**3. Stored product pests**

### **3.1. The Indian meal moth (***Plodia interpunctella* **[Hübner]; Lepidoptera, Pyralidae)**

The Indian meal moth is a serious and widespread pest of many stored food commodities (Sedlacek et al., 1996). The larval stage causes the injury. Larvae feed on flour and meal products, dried fruits, nuts, bird food, and dried pet foods. More unusual recorded foods include chocolate and cocoa beans, coffee substitute, cookies, flour, dried mangelwurzel, and even the toxic seeds of Jimsonweed (*Datura stramonium*). As the larva feeds it spins a web, leaving behind a silken thread wherever it crawls. Small particles of food often adhere loosely to the thread, making it conspicuous. Many times an infestation is noticed when moths are seen flying around the home in the evening. They are attracted to lights and often appear in front of the television screen (Sedlacek et al., 1996).

The Indian meal moth has a wingspan of about 18-20 mm. The color of the outer two-thirds of the wings is bronze to reddish brown, while the part of the wings closer to the body is grayish white. The larvae (caterpillars) are about 12-13 mm long when mature. They are a dirty white color, sometimes exhibiting pink or green hues. The pupa (resting stage) is in a loose silken cocoon spun by the larva, and is a light brown color (Hinton, 1943).

A female Indian meal moth can lay from 100 to 300 eggs during her lifetime. Eggs are laid singly or in groups on the food materials. Within a few days the tiny whitish caterpillars emerge. These larvae feed for a few weeks, and when they are mature they often crawl up the walls to where wall and ceiling meet, or crawl to the top of the cupboard, to spin the silken cocoon in which they pupate and from which the adult moth emerges. Mating occurs and the life cycle repeats itself. In warm weather the cycle may take only 6 to 8 weeks (Hinton, 1943).

Female *P. interpunctella* and females of other stored product moths of the subfamiliy Phycitinae produce Z-9, E-12-tetradecandienyl acetate as a component of their sex pheromone blends (Bra‐ dy et al., 1971). Traps baited with synthetic pheromone are effective and widely used to monitor male stored-product moths (Vick et al., 1986; Chambers, 1990). Pheromone-baited traps have proven successful in detecting low level infestations of these moths (Vick et al., 1986).

In 2004-2005, pheromone traps (VARL+ type, (Csal♀m♂N® Budapest, Hungary) were used to monitor the occurrence of Indianmeal moth in Slovenia. The pheromone traps were set from March to December. Indianmeal moth was monitored during 2004 and 2005 in Želimlje and Jable and during 2004-2006 in Obrije. In Želimlje, the lepidopterian pests were monitored using two traps hung under the ceiling of a corn open air storage (part of a barn). It was used for storage of corn (corncobs) from harvest (the end of Sep‐ tember) till the end of July. In the lower part (under this corn open air storage) corn that was ground into flour was kept. In Obrije, an organic farm was monitored using four traps, three in the storage room and one in the mill. In Jable, the traps were placed in the Agricultural Centre, with one trap in the grain storage, a second one in the mill, and two outside the building (in front of the storage). At none of these locations were treat‐ ments against stored pests performed. Following the manufacturer's instructions, the pheromone lures were changed monthly. They were checked in 7 day intervals (Želimlje) or 14 day intervals (Obrije and Jable). The trapped males were stored in the lab at room temperature until identification. The determination was carried out using a Olympus SZ30 (manufacturer: Olympus Europa Gmbh, Hamburg, Germany) stereomicroscope (magnification about 10 times). The number of the trapped moths/day was calculated as the intervals were not the same for all the locations (Trdan et al., 2010).

The Goat Moth (*Cossus cossus* [L.]; Lepidoptera, Cossidae)

150 Insecticides - Development of Safer and More Effective Technologies

appear in front of the television screen (Sedlacek et al., 1996).

In warm weather the cycle may take only 6 to 8 weeks (Hinton, 1943).

Tortricidae)

**3. Stored product pests**

The European grape berry moth (*Clysia ambiguella* [Hübner]; Lepidoptera, Tortricidae)

**3.1. The Indian meal moth (***Plodia interpunctella* **[Hübner]; Lepidoptera, Pyralidae)**

The Indian meal moth is a serious and widespread pest of many stored food commodities (Sedlacek et al., 1996). The larval stage causes the injury. Larvae feed on flour and meal products, dried fruits, nuts, bird food, and dried pet foods. More unusual recorded foods include chocolate and cocoa beans, coffee substitute, cookies, flour, dried mangelwurzel, and even the toxic seeds of Jimsonweed (*Datura stramonium*). As the larva feeds it spins a web, leaving behind a silken thread wherever it crawls. Small particles of food often adhere loosely to the thread, making it conspicuous. Many times an infestation is noticed when moths are seen flying around the home in the evening. They are attracted to lights and often

The Indian meal moth has a wingspan of about 18-20 mm. The color of the outer two-thirds of the wings is bronze to reddish brown, while the part of the wings closer to the body is grayish white. The larvae (caterpillars) are about 12-13 mm long when mature. They are a dirty white color, sometimes exhibiting pink or green hues. The pupa (resting stage) is in a

A female Indian meal moth can lay from 100 to 300 eggs during her lifetime. Eggs are laid singly or in groups on the food materials. Within a few days the tiny whitish caterpillars emerge. These larvae feed for a few weeks, and when they are mature they often crawl up the walls to where wall and ceiling meet, or crawl to the top of the cupboard, to spin the silken cocoon in which they pupate and from which the adult moth emerges. Mating occurs and the life cycle repeats itself.

Female *P. interpunctella* and females of other stored product moths of the subfamiliy Phycitinae produce Z-9, E-12-tetradecandienyl acetate as a component of their sex pheromone blends (Bra‐ dy et al., 1971). Traps baited with synthetic pheromone are effective and widely used to monitor male stored-product moths (Vick et al., 1986; Chambers, 1990). Pheromone-baited traps have

In 2004-2005, pheromone traps (VARL+ type, (Csal♀m♂N® Budapest, Hungary) were used to monitor the occurrence of Indianmeal moth in Slovenia. The pheromone traps were set from March to December. Indianmeal moth was monitored during 2004 and 2005 in Želimlje and Jable and during 2004-2006 in Obrije. In Želimlje, the lepidopterian pests were monitored using two traps hung under the ceiling of a corn open air storage (part of a barn). It was used for storage of corn (corncobs) from harvest (the end of Sep‐

proven successful in detecting low level infestations of these moths (Vick et al., 1986).

loose silken cocoon spun by the larva, and is a light brown color (Hinton, 1943).

The European Grapevine Moth (*Lobesia botrana* [Denis & Schiffermüller]; Lepidoptera,

Figure 1. Number of *Plodia interpunctella* males caught by pheromone traps in Želimlje (1), Obrije (2) and Jable (3) in 2004 (a) and 2005 (b). The males of Indianmeal moth were most numerous in Obrije during the three years of the study. The results suggest two peaks of **Figure 2.** Number of *Plodia interpunctella* males caught by pheromone traps in Želimlje (1), Obrije (2) and Jable (3) in 2004 (a) and 2005 (b).

**3.2. Mediterranean Flour Moth (***Ephestia kuehniella* **[Zeller]; Lepidoptera, Pyralidae)** 

activity of Indianmeal moth outside wheat flour meal compared to inside of them.

insects (Cox and Bell, 1991).

flight activity, perhaps correlated with generations, of this moth, with the first being rather more numerous (figure 2). The first peak occurred during the second half of July (7-9 males/trap/day). In all three years, the second peak was in the middle of September, with captures of 2 males/trap/day. In Jable, the pest also showed two capture peaks as in Obrije, but captures were less numerous. This can be explained by the fact that two traps were set outside the storage, were only single specimens were captured. The first peak in captures at this location was during the second half of July, and captures were five times more numerous in 2004 (4 males/trap/day) compared to the next year. The second peak in captures was less numerous and appeared at the end of August and in September. In Želimlje captures of Indianmeal moth were the least numerous, probably because monitoring was in a nonprotected open air storage, where corncobs were stored. There was never more than 1 male/trap/day caught at this location, and adults were active from the beginning of June till the end of September (both years) (Trdan et al., 2010). Part of this research was published by Selišnik in 2007. These results are opposite to reports of Campbell and Arbogast (2004), who found the greater

*E. kuehniella* is found worlwide but not abundant in the tropic region. The complete life-cycle of this species takes about 50 days. Mediterranean Flour Moth larvae mainly feed on wheat flour but are recorded from a wide range of commodities and from dead The males of Indianmeal moth were most numerous in Obrije during the three years of the study. The results suggest two peaks of flight activity, perhaps correlated with gener‐ ations, of this moth, with the first being rather more numerous (figure 2). The first peak occurred during the second half of July (7-9 males/trap/day). In all three years, the sec‐ ond peak was in the middle of September, with captures of 2 males/trap/day. In Jable, the pest also showed two capture peaks as in Obrije, but captures were less numerous. This can be explained by the fact that two traps were set outside the storage, were only single specimens were captured. The first peak in captures at this location was during the second half of July, and captures were five times more numerous in 2004 (4 males/ trap/day) compared to the next year. The second peak in captures was less numerous and appeared at the end of August and in September. In Želimlje captures of Indianmeal moth were the least numerous, probably because monitoring was in a non-protected open air storage, where corncobs were stored. There was never more than 1 male/ trap/day caught at this location, and adults were active from the beginning of June till the end of September (both years) (Trdan et al., 2010). Part of this research was publish‐ ed by Selišnik in 2007. These results are opposite to reports of Campbell and Arbogast (2004), who found the greater activity of Indianmeal moth outside wheat flour meal com‐ pared to inside of them.

#### **3.2. Mediterranean Flour Moth (***Ephestia kuehniella* **[Zeller]; Lepidoptera, Pyralidae)**

*E. kuehniella* is found worlwide but not abundant in the tropic region. The complete life-cy‐ cle of this species takes about 50 days. Mediterranean Flour Moth larvae mainly feed on wheat flour but are recorded from a wide range of commodities and from dead insects (Cox and Bell, 1991).

The surface of the newly laid eggs of *E. kuehniella* is white in colour, and shining irides‐ cent when observed by reflected light (Garcia-Barros, 2000). Just before hatching the egg turns light yellow in color due to the development of the embryo which can be seen through the shell of the egg at this time. The egg is 500-550 µm long by 290-325 µm wide. *E. kuehniella* larvae are 0.866 mm long and 0.199 mm wide on average immediately after hatching (Garcia-Barros, 2000). The newly hatched larvae are cream coloured and sparsely covered with long hairs. *E. kuehniella* larvae have six instars (Cox and Bell, 1991). Mature larvae crawl to the surface of the material on which they have fed, and spin silk cocoons intermingled with particles of meal and flour for pupation. Pupae are pale green at the early stage and then turn to reddish brown on the dorsal side of the thoerax. On the last day of development, pupae become dark in color (Garcia-Barros, 2000). Adults are 10-14 mm long when at rest, with wingspan beiing 20-25 mm; forew‐ ings are blue-grey with transverse dark wavy bars and a row of dark spots at the tip; hindwing are dirty white with fuscous veins.

Figure 2. Number of *Ephestia kuehniella* males caught by pheromone traps in Želimlje (1), Obrije (2) and Jable (3) in 2004 (a) and 2005 (b).

**Time interval**

**Figure 3.** Number of *Ephestia kuehniella* males caught by pheromone traps in Želimlje (1), Obrije (2) and Jable (3) in

Mediterranean flour moth captures in the pheromone traps were more numerous than cap‐ tures of *Plodia interpunctella*. The captures of this pest, which appeared to have two peaks in capture, was most numerous in Želimlje, where the first peak was in the beginning of June (both years) – 22 to 25 males/trap/day. Later in the year the abundance of this moth de‐

fuscous veins.

2004 (a) and 2005 (b).

02.05.-09.05. 09.05.-16.05. 16.05.-23.05. 23.05.-30.05. 30.05.-06.06. 06.06.-13.06. 13.06.-20.06. 20.06.-27.06. 27.06.-04.07. 04.07.-11.07. 11.07.-17.07. 17.07.-22.07. 22.07.-01.08. 01.08.-08.08. 08.08.-17.08. 17.08.-22.08. 22.08.-01.09. 01.09.-06.09. 06.09.-12.09. 12.09.-19.09. 19.09.-27.09. 27.09.-05.10. 05.10.-17.10. 17.10.-01.11.

23.04.-05.05.

18.05.-03.06.

03.06.-23.06.

23.06.-15.07.

15.07.- 28.7.

28.07.-11.08.

11.08.-24.08.

24.08.-08.09.

08.09.-22.09.

22.09.-06.10.

6.10.-19.10.

19.10.-04.11.

4.11.-15.11.

**No. males/trap/day**

05.05.-19.05.

19.05.-02.06.

02.06.-16.06.

16.06.-30.06.

30.06.-14.07.

14.07.-28.07.

28.07.-11.08.

11.08.-25.08.

25.08.-09.09.

2a) 2b)

09.09.-22.09.

22.09.-06.10.

06.10.-19.10.

19.10.-04.11.

4.11.-15.11.

1a) 1b)

The surface of the newly laid eggs of *E. kuehniella* is white in colour, and shining iridescent when observed by reflected light (Garcia-Barros, 2000). Just before hatching the egg turns light yellow in color due to the development of the embryo which can be seen through the shell of the egg at this time. The egg is 500-550 μm long by 290-325 μm wide. *E. kuehniella* larvae are 0.866 mm long and 0.199 mm wide on average immediately after hatching (Garcia-Barros, 2000). The newly hatched larvae are cream coloured and sparsely covered with long hairs. *E. kuehniella* larvae have six instars (Cox and Bell, 1991). Mature larvae crawl to the surface of the material on which they have fed, and spin silk cocoons intermingled with particles of meal and flour for pupation. Pupae are pale green at the early stage and then turn to reddish brown on the dorsal side of the thoerax. On the last day of development, pupae become dark in color (Garcia-Barros, 2000). Adults are 10-14 mm long when at rest, with wingspan beiing 20- 25 mm; forewings are blue-grey with transverse dark wavy bars and a row of dark spots at the tip; hindwing are dirty white with

20.04.-04.05.

04.05.-18.05.

18.05.-01.06.

01.06.-15.06.

15.06.-29.06.

29.06.-14.07.

14.07.-27.07.

27.07.-10.08.

10.08.-24.08.

24.08.-07.09.

07.09.-21.09.

21.09.-07.10.

07.10.-19.10.

19.10.-02.11.

02.11.-16.11.

16.11.-07.12.

28.03.-10.04. 10.04.-25.04.

Research on Seasonal Dynamics of 14 Different Insects Pests in Slovenia Using Pheromone Traps

23.03.-06.04.

06.04.-20.04.

20.04.-04.05.

04.05.-18.05.

18.05.-01.06.

01.06.-15.06.

15.06.-29.06.

29.06.-14.07.

14.07.-27.07.

27.07.-10.08.

10.08.-24.08.

24.08.-07.09.

07.09.-21.09.

21.09.-07.10.

07.10.-19.10.

19.10.-02.11.

02.11.-16.11.

16.11.-07.12.

25.04.-08.05.

08.05.-22.05.

22.05.-01.06.

01.06.-05.06.

05.06.-11.06.

11.06.-26.06.

26.06.-03.07.

03.07.-10.07.

10.07.-16.07.

16.07.-24.07.

24.07.-01.08.

01.08.-14.08.

http://dx.doi.org/10.5772/53186

153

14.08.-22.08.

22.08.-04.09.

04.09.-10.10.

In Slovenia the pest was monitored simultaneously with *Plodia interpunctella* males (in the same pheromone lures) since the manufacturer does not offer a specific pheromone for each species. Therefore the same material and methods as it is presented for

Mediterranean flour moth captures in the pheromone traps were more numerous than captures of *Plodia interpunctella*. The captures of this pest, which appeared to have two peaks in capture, was most numerous in Želimlje, where the first peak was in the beginning of June (both years) – 22 to 25 males/trap/day. Later in the year the abundance of this moth decreased significantly, possibly also due to removal of the stored corncobs from the previous season. Single males were found in the traps till the end of the monitoring in October. In closed storage rooms, In Obrije and Jable, captures of Mediterranean flour moth were less numerous, the peak being about 7 males/trap/day in Obrije in the second half of July. The males at these locations were spotted from the

**3.3. The Angoumois grain moth (***Sitotroga cerealella* **[Olivier]; Lepidoptera, Gelechiidae)**

*Plodia interpunctella* (see the 5th paragraph of the chapter 1.1.) was used (Trdan et al., 2010).

beginning of June until October (Figure 3). Part of this research was published by Selišnik in 2007.

In Slovenia the pest was monitored simultaneously with *Plodia interpunctella* males (in the same pheromone lures) since the manufacturer does not offer a specific pheromone for each species. Therefore the same material and methods as it is presented for *Plodia interpunctella* (see the 5th paragraph of the chapter 1.1.) was used (Trdan et al., 2010).

The males of Indianmeal moth were most numerous in Obrije during the three years of the study. The results suggest two peaks of flight activity, perhaps correlated with gener‐ ations, of this moth, with the first being rather more numerous (figure 2). The first peak occurred during the second half of July (7-9 males/trap/day). In all three years, the sec‐ ond peak was in the middle of September, with captures of 2 males/trap/day. In Jable, the pest also showed two capture peaks as in Obrije, but captures were less numerous. This can be explained by the fact that two traps were set outside the storage, were only single specimens were captured. The first peak in captures at this location was during the second half of July, and captures were five times more numerous in 2004 (4 males/ trap/day) compared to the next year. The second peak in captures was less numerous and appeared at the end of August and in September. In Želimlje captures of Indianmeal moth were the least numerous, probably because monitoring was in a non-protected open air storage, where corncobs were stored. There was never more than 1 male/ trap/day caught at this location, and adults were active from the beginning of June till the end of September (both years) (Trdan et al., 2010). Part of this research was publish‐ ed by Selišnik in 2007. These results are opposite to reports of Campbell and Arbogast (2004), who found the greater activity of Indianmeal moth outside wheat flour meal com‐

**3.2. Mediterranean Flour Moth (***Ephestia kuehniella* **[Zeller]; Lepidoptera, Pyralidae)**

*E. kuehniella* is found worlwide but not abundant in the tropic region. The complete life-cy‐ cle of this species takes about 50 days. Mediterranean Flour Moth larvae mainly feed on wheat flour but are recorded from a wide range of commodities and from dead insects (Cox

The surface of the newly laid eggs of *E. kuehniella* is white in colour, and shining irides‐ cent when observed by reflected light (Garcia-Barros, 2000). Just before hatching the egg turns light yellow in color due to the development of the embryo which can be seen through the shell of the egg at this time. The egg is 500-550 µm long by 290-325 µm wide. *E. kuehniella* larvae are 0.866 mm long and 0.199 mm wide on average immediately after hatching (Garcia-Barros, 2000). The newly hatched larvae are cream coloured and sparsely covered with long hairs. *E. kuehniella* larvae have six instars (Cox and Bell, 1991). Mature larvae crawl to the surface of the material on which they have fed, and spin silk cocoons intermingled with particles of meal and flour for pupation. Pupae are pale green at the early stage and then turn to reddish brown on the dorsal side of the thoerax. On the last day of development, pupae become dark in color (Garcia-Barros, 2000). Adults are 10-14 mm long when at rest, with wingspan beiing 20-25 mm; forew‐ ings are blue-grey with transverse dark wavy bars and a row of dark spots at the tip;

In Slovenia the pest was monitored simultaneously with *Plodia interpunctella* males (in the same pheromone lures) since the manufacturer does not offer a specific pheromone for each species. Therefore the same material and methods as it is presented for *Plodia interpunctella*

(see the 5th paragraph of the chapter 1.1.) was used (Trdan et al., 2010).

pared to inside of them.

152 Insecticides - Development of Safer and More Effective Technologies

hindwing are dirty white with fuscous veins.

and Bell, 1991).

long and 0.199 mm wide on average immediately after hatching (Garcia-Barros, 2000). The newly hatched larvae are cream coloured and sparsely covered with long hairs. *E. kuehniella* larvae have six instars (Cox and Bell, 1991). Mature larvae crawl to the **Figure 3.** Number of *Ephestia kuehniella* males caught by pheromone traps in Želimlje (1), Obrije (2) and Jable (3) in 2004 (a) and 2005 (b).

Figure 2. Number of *Ephestia kuehniella* males caught by pheromone traps in Želimlje (1), Obrije (2) and Jable (3) in 2004 (a) and 2005 (b).

The surface of the newly laid eggs of *E. kuehniella* is white in colour, and shining iridescent when observed by reflected light (Garcia-Barros, 2000). Just before hatching the egg turns light yellow in color due to the development of the embryo which can be seen through the shell of the egg at this time. The egg is 500-550 μm long by 290-325 μm wide. *E. kuehniella* larvae are 0.866 mm

surface of the material on which they have fed, and spin silk cocoons intermingled with particles of meal and flour for pupation.

manufacturer does not offer a specific pheromone for each species. Therefore the same material and methods as it is presented for

Mediterranean flour moth captures in the pheromone traps were more numerous than captures of *Plodia interpunctella*. The captures of this pest, which appeared to have two peaks in capture, was most numerous in Želimlje, where the first peak was in the beginning of June (both years) – 22 to 25 males/trap/day. Later in the year the abundance of this moth decreased significantly, possibly also due to removal of the stored corncobs from the previous season. Single males were found in the traps till the end of the monitoring in October. In closed storage rooms, In Obrije and Jable, captures of Mediterranean flour moth were less numerous, the peak being about 7 males/trap/day in Obrije in the second half of July. The males at these locations were spotted from the

**3.3. The Angoumois grain moth (***Sitotroga cerealella* **[Olivier]; Lepidoptera, Gelechiidae)**

Pupae are pale green at the early stage and then turn to reddish brown on the dorsal side of the thoerax. On the last day of development, pupae become dark in color (Garcia-Barros, 2000). Adults are 10-14 mm long when at rest, with wingspan beiing 20- 25 mm; forewings are blue-grey with transverse dark wavy bars and a row of dark spots at the tip; hindwing are dirty white with fuscous veins. In Slovenia the pest was monitored simultaneously with *Plodia interpunctella* males (in the same pheromone lures) since the Mediterranean flour moth captures in the pheromone traps were more numerous than cap‐ tures of *Plodia interpunctella*. The captures of this pest, which appeared to have two peaks in capture, was most numerous in Želimlje, where the first peak was in the beginning of June (both years) – 22 to 25 males/trap/day. Later in the year the abundance of this moth de‐

*Plodia interpunctella* (see the 5th paragraph of the chapter 1.1.) was used (Trdan et al., 2010).

beginning of June until October (Figure 3). Part of this research was published by Selišnik in 2007.

creased significantly, possibly also due to removal of the stored corncobs from the previous season. Single males were found in the traps till the end of the monitoring in October. In closed storage rooms, In Obrije and Jable, captures of Mediterranean flour moth were less numerous, the peak being about 7 males/trap/day in Obrije in the second half of July. The males at these locations were spotted from the beginning of June until October (Figure 3). Part of this research was published by Selišnik in 2007.

*Sitotroga cerealella* (Olivier) is an important pest of stored grains, whose biology has been well researched (Shazali, 1990). The Angoumois grain moth overwinters as mature larvae that pupate in a silken cocoon in the grain during early spring. Larvae feed inside whole grains on the germ and endosperm, completely destroying the kernel (Arbogast and Mullen, 1987). This insect prefers damp grain to old dry grain, especially barley, corn, oats, wheat, and various seeds. This pest may infest grain, especially wheat

Adults are small, buff or yellowish-white moths with pale yellow forewings and gray, pointed hind wings with a wingspan of 12 mm. The forewings are marked with a few darker lines, and the hind wings are notched at the apical end. The wings also have long fringe around the margins. Mature larvae are pale yellow and about 6 mm long with poorly developed prolegs on the abdomen (Arbogast and Mullen, 1987). Adults emerge in May and June and females begin laying eggs singly or in clusters on or near the grain. Eggs hatch in about a week during the summer, but may require up to four weeks to hatch when temperatures are cooler. Young larvae enter the grain immediately. Larvae mature in two to three weeks, and construct an escape tunnel in the grain through which adults can later emerge. The pupal stage lasts about two weeks (Shazali, 1990). Under favourable conditions, the life cycle may be completed in five to seven weeks. In colder climates, larvae become dormant for four to five months and the life cycle may take up to six months to complete. In unheated storage, there are two generations each year. In heated storage, there are

The results of investigation in Slovenia (for material and methods see the 5th paragraph of chapter 1.1.), which was performed in Obrije in the period 2005-2006, showing a typical two peaks in flight activity, allow the conclusion, that, on the average, the species under investigation develop two generations under the conditions in Central Slovenia (Figure 4). The results of our research showed that in 2005, the first males of Angoumois grain moth were caught in the first half of June, while more substantial numbers (more than 2 males/trap/day) were observed in Obrije in the first half of July. This period may correspond with the peak of first generation of the year. As the study went on, a second peak was observed in the midst of September (6 males/trap/day), which could indicate a second generation. The adults were active till the first half of November. In 2006, the pest was less numerous and the first specimens were found in the traps during the second half of June. As in 2005, two peaks in trap capture were observed, the

Research on Seasonal Dynamics of 14 Different Insects Pests in Slovenia Using Pheromone Traps

peaks being 1 male/trap/day at the beginning of July and in the midst of September (Trdan et al., 2010; Zalokar, 2010).

**Time interval**

20.04.-04.05.

04.05.-17.05.

17.05.-31.05.

31.05.-14.06.

14.06.-28.06.

28.06.-12.07.

12.07.-26.07.

26.07.-09.08.

09.08.-23.08.

23.08.-06.09.

06.09.-20.09.

20.09.-04.10.

04.10.-18.10.

18.10.-01.11.

http://dx.doi.org/10.5772/53186

155

01.11.-14.11.

14.11.-29.11.

29.11.-13.12.

Figure 3. Number of *Sitotroga cerealella* males caught by pheromone traps in Obrije in 2005 (a) and 2006 (b).

**4.1. Swede midge (***Contarinia nasturtii* **[Kieffer]; Diptera, Cecidomyiidae)** 

The Swede midge is a pest of most cultivated Brassicaceae such as broccoli, canola, cauli‐ flower, cabbage, and Brussels sprouts. The species primarily has a Palaearctic distribution and occurs throughout Europe and southwestern Asia to the Caucasus (Olfert *et al*., 2006). Plant damage is caused by larval feeding; symptoms include misshapen plants and the for‐ mation of galls on leaves and flowers (Bardner et al., 1971). The larval stage overwinters in the soil, adults emerge in May and females lay eggs, in clusters of 2–50, on the surface of actively growing plants. Larvae feed on actively growing stems, leaves, and flowers, then drop to the soil to pupate. During the growing season, adults can emerge within 2 weeks or larvae enter diapause in autumn. Depending on temperature and soil moisture, *C. nasturtii* may have 2–5 generations (Hallett and Heal, 2001). Temperature and moisture have been identified to be the two most important factors responsible for population distribution, growth, and control. Population growth was greatest in warm, moist seasons and reduced

In 2004, the occurrence of Swede midge on four locations in Slovenia (Ljubljana, Rakitnica, Zakl near Braslovče, Škocjan near Koper) was investigated (Figure 5). Pheromone traps of the Swiss producer (Agroscope FAW, Wädenswill) were set in fields with Brassica plants. The aim of the research was to determine a population dynamics of the pest in vegetation period, to establish the number of generations it develops per year in geographically and cli‐ matically different regions. Understanding of the pest bionomics would help to set a strat‐ egy for control of Swede midge in Brassica plants. The results of the monitoring indicate that the species has 4 generations per year, also in the continental part of the country. In all four locations a generation was also established in September (Trdan et al., 2005a). Part of

**4.1. Swede midge (***Contarinia nasturtii* **[Kieffer]; Diptera, Cecidomyiidae)**

**Figure 4.** Number of *Sitotroga cerealella* males caught by pheromone traps in Obrije in 2005 (a) and 2006 (b).

growth was greatest in warm, moist seasons and reduced in cool or dry seasons (Readshaw, 1966).

The Swede midge is a pest of most cultivated Brassicaceae such as broccoli, canola, cauliflower, cabbage, and Brussels sprouts. The species primarily has a Palaearctic distribution and occurs throughout Europe and southwestern Asia to the Caucasus (Olfert *et al*., 2006). Plant damage is caused by larval feeding; symptoms include misshapen plants and the formation of galls on leaves and flowers (Bardner et al., 1971). The larval stage overwinters in the soil, adults emerge in May and females lay eggs, in clusters of 2– 50, on the surface of actively growing plants. Larvae feed on actively growing stems, leaves, and flowers, then drop to the soil to pupate. During the growing season, adults can emerge within 2 weeks or larvae enter diapause in autumn. Depending on temperature and soil moisture, *C. nasturtii* may have 2–5 generations (Hallett and Heal, 2001). Temperature and moisture have been identified to be the two most important factors responsible for population distribution, growth, and control. Population

In 2004, the occurrence of Swede midge on four locations in Slovenia (Ljubljana, Rakitnica, Zakl near Braslovče, Škocjan near Koper) was investigated (Figure 5). Pheromone traps of the Swiss producer (Agroscope FAW, Wädenswill) were set in fields with Brassica plants. The aim of the research was to determine a population dynamics of the pest in vegetation period, to establish the

**4. Vegetable pests** 

in cool or dry seasons (Readshaw, 1966).

this research was published by Walland in 2007.

**4. Vegetable pests**

23.03.-06.04. 06.04.-20.04. 20.04.-04.05. 04.05.-18.05. 18.05.-01.06. 01.06.-15.06. 15.06.-29.06. 29.06.-14.07. 14.07.-27.07. 27.07.-10-08. 10.08.-24.08. 24.08.-07.09. 07.09.-21.09. 21.09.-07.10. 07.10.-19.10. 19.10.-02.11. 02.11.-16.11. 16.11.-07.12.

a)

**No. males/trap/day**

and corn, before harvest while it is still standing in the field (Arbogast and Mullen, 1987).

usually four to five generations per year (Arbogast and Mullen, 1987).

#### **3.3. The Angoumois grain moth (***Sitotroga cerealella* **[Olivier]; Lepidoptera, Gelechiidae)**

*Sitotroga cerealella* (Olivier) is an important pest of stored grains, whose biology has been well researched (Shazali, 1990). The Angoumois grain moth overwinters as mature larvae that pupate in a silken cocoon in the grain during early spring. Larvae feed inside whole grains on the germ and endosperm, completely destroying the kernel (Arbogast and Mullen, 1987). This insect prefers damp grain to old dry grain, especially barley, corn, oats, wheat, and various seeds. This pest may infest grain, especially wheat and corn, before harvest while it is still standing in the field (Arbogast and Mullen, 1987).

Adults are small, buff or yellowish-white moths with pale yellow forewings and gray, point‐ ed hind wings with a wingspan of 12 mm. The forewings are marked with a few darker lines, and the hind wings are notched at the apical end. The wings also have long fringe around the margins. Mature larvae are pale yellow and about 6 mm long with poorly devel‐ oped prolegs on the abdomen (Arbogast and Mullen, 1987). Adults emerge in May and June and females begin laying eggs singly or in clusters on or near the grain. Eggs hatch in about a week during the summer, but may require up to four weeks to hatch when temperatures are cooler. Young larvae enter the grain immediately. Larvae mature in two to three weeks, and construct an escape tunnel in the grain through which adults can later emerge. The pu‐ pal stage lasts about two weeks (Shazali, 1990). Under favourable conditions, the life cycle may be completed in five to seven weeks. In colder climates, larvae become dormant for four to five months and the life cycle may take up to six months to complete. In unheated storage, there are two generations each year. In heated storage, there are usually four to five generations per year (Arbogast and Mullen, 1987).

The results of investigation in Slovenia (for material and methods see the 5th paragraph of chapter 1.1.), which was performed in Obrije in the period 2005-2006, showing a typical two peaks in flight activity, allow the conclusion, that, on the average, the species under investi‐ gation develop two generations under the conditions in Central Slovenia (Figure 4). The re‐ sults of our research showed that in 2005, the first males of Angoumois grain moth were caught in the first half of June, while more substantial numbers (more than 2 males/trap/ day) were observed in Obrije in the first half of July. This period may correspond with the peak of first generation of the year. As the study went on, a second peak was observed in the midst of September (6 males/trap/day), which could indicate a second generation. The adults were active till the first half of November. In 2006, the pest was less numerous and the first specimens were found in the traps during the second half of June. As in 2005, two peaks in trap capture were observed, the peaks being 1 male/trap/day at the beginning of July and in the midst of September (Trdan et al., 2010; Zalokar, 2010).

*Sitotroga cerealella* (Olivier) is an important pest of stored grains, whose biology has been well researched (Shazali, 1990). The Angoumois grain moth overwinters as mature larvae that pupate in a silken cocoon in the grain during early spring. Larvae feed inside whole grains on the germ and endosperm, completely destroying the kernel (Arbogast and Mullen, 1987). This insect prefers damp grain to old dry grain, especially barley, corn, oats, wheat, and various seeds. This pest may infest grain, especially wheat

Adults are small, buff or yellowish-white moths with pale yellow forewings and gray, pointed hind wings with a wingspan of 12 mm. The forewings are marked with a few darker lines, and the hind wings are notched at the apical end. The wings also have long fringe around the margins. Mature larvae are pale yellow and about 6 mm long with poorly developed prolegs on the abdomen (Arbogast and Mullen, 1987). Adults emerge in May and June and females begin laying eggs singly or in clusters on or near the grain. Eggs hatch in about a week during the summer, but may require up to four weeks to hatch when temperatures are cooler. Young larvae enter the grain immediately. Larvae mature in two to three weeks, and construct an escape tunnel in the grain through which adults can later emerge. The pupal stage lasts about two weeks (Shazali, 1990). Under favourable conditions, the life cycle may be completed in five to seven weeks. In colder climates, larvae become dormant for four to five months and the life cycle may take up to six months to complete. In unheated storage, there are two generations each year. In heated storage, there are

The results of investigation in Slovenia (for material and methods see the 5th paragraph of chapter 1.1.), which was performed in Obrije in the period 2005-2006, showing a typical two peaks in flight activity, allow the conclusion, that, on the average, the species under investigation develop two generations under the conditions in Central Slovenia (Figure 4). The results of our research showed that in 2005, the first males of Angoumois grain moth were caught in the first half of June, while more substantial numbers (more than 2 males/trap/day) were observed in Obrije in the first half of July. This period may correspond with the peak of first

and corn, before harvest while it is still standing in the field (Arbogast and Mullen, 1987).

usually four to five generations per year (Arbogast and Mullen, 1987).

peaks being 1 male/trap/day at the beginning of July and in the midst of September (Trdan et al., 2010; Zalokar, 2010).

Figure 3. Number of *Sitotroga cerealella* males caught by pheromone traps in Obrije in 2005 (a) and 2006 (b). **Figure 4.** Number of *Sitotroga cerealella* males caught by pheromone traps in Obrije in 2005 (a) and 2006 (b).

#### **4.1. Swede midge (***Contarinia nasturtii* **[Kieffer]; Diptera, Cecidomyiidae) 4. Vegetable pests**

**4. Vegetable pests** 

creased significantly, possibly also due to removal of the stored corncobs from the previous season. Single males were found in the traps till the end of the monitoring in October. In closed storage rooms, In Obrije and Jable, captures of Mediterranean flour moth were less numerous, the peak being about 7 males/trap/day in Obrije in the second half of July. The males at these locations were spotted from the beginning of June until October (Figure 3).

**3.3. The Angoumois grain moth (***Sitotroga cerealella* **[Olivier]; Lepidoptera, Gelechiidae)**

*Sitotroga cerealella* (Olivier) is an important pest of stored grains, whose biology has been well researched (Shazali, 1990). The Angoumois grain moth overwinters as mature larvae that pupate in a silken cocoon in the grain during early spring. Larvae feed inside whole grains on the germ and endosperm, completely destroying the kernel (Arbogast and Mullen, 1987). This insect prefers damp grain to old dry grain, especially barley, corn, oats, wheat, and various seeds. This pest may infest grain, especially wheat and corn, before harvest

Adults are small, buff or yellowish-white moths with pale yellow forewings and gray, point‐ ed hind wings with a wingspan of 12 mm. The forewings are marked with a few darker lines, and the hind wings are notched at the apical end. The wings also have long fringe around the margins. Mature larvae are pale yellow and about 6 mm long with poorly devel‐ oped prolegs on the abdomen (Arbogast and Mullen, 1987). Adults emerge in May and June and females begin laying eggs singly or in clusters on or near the grain. Eggs hatch in about a week during the summer, but may require up to four weeks to hatch when temperatures are cooler. Young larvae enter the grain immediately. Larvae mature in two to three weeks, and construct an escape tunnel in the grain through which adults can later emerge. The pu‐ pal stage lasts about two weeks (Shazali, 1990). Under favourable conditions, the life cycle may be completed in five to seven weeks. In colder climates, larvae become dormant for four to five months and the life cycle may take up to six months to complete. In unheated storage, there are two generations each year. In heated storage, there are usually four to five

The results of investigation in Slovenia (for material and methods see the 5th paragraph of chapter 1.1.), which was performed in Obrije in the period 2005-2006, showing a typical two peaks in flight activity, allow the conclusion, that, on the average, the species under investi‐ gation develop two generations under the conditions in Central Slovenia (Figure 4). The re‐ sults of our research showed that in 2005, the first males of Angoumois grain moth were caught in the first half of June, while more substantial numbers (more than 2 males/trap/ day) were observed in Obrije in the first half of July. This period may correspond with the peak of first generation of the year. As the study went on, a second peak was observed in the midst of September (6 males/trap/day), which could indicate a second generation. The adults were active till the first half of November. In 2006, the pest was less numerous and the first specimens were found in the traps during the second half of June. As in 2005, two peaks in trap capture were observed, the peaks being 1 male/trap/day at the beginning of

Part of this research was published by Selišnik in 2007.

154 Insecticides - Development of Safer and More Effective Technologies

while it is still standing in the field (Arbogast and Mullen, 1987).

generations per year (Arbogast and Mullen, 1987).

July and in the midst of September (Trdan et al., 2010; Zalokar, 2010).

#### species primarily has a Palaearctic distribution and occurs throughout Europe and southwestern Asia to the Caucasus (Olfert *et al*., **4.1. Swede midge (***Contarinia nasturtii* **[Kieffer]; Diptera, Cecidomyiidae)**

flowers (Bardner et al., 1971). The larval stage overwinters in the soil, adults emerge in May and females lay eggs, in clusters of 2– 50, on the surface of actively growing plants. Larvae feed on actively growing stems, leaves, and flowers, then drop to the soil to pupate. During the growing season, adults can emerge within 2 weeks or larvae enter diapause in autumn. Depending on temperature and soil moisture, *C. nasturtii* may have 2–5 generations (Hallett and Heal, 2001). Temperature and moisture have been identified to be the two most important factors responsible for population distribution, growth, and control. Population growth was greatest in warm, moist seasons and reduced in cool or dry seasons (Readshaw, 1966). In 2004, the occurrence of Swede midge on four locations in Slovenia (Ljubljana, Rakitnica, Zakl near Braslovče, Škocjan near Koper) was investigated (Figure 5). Pheromone traps of the Swiss producer (Agroscope FAW, Wädenswill) were set in fields with Brassica plants. The aim of the research was to determine a population dynamics of the pest in vegetation period, to establish the The Swede midge is a pest of most cultivated Brassicaceae such as broccoli, canola, cauli‐ flower, cabbage, and Brussels sprouts. The species primarily has a Palaearctic distribution and occurs throughout Europe and southwestern Asia to the Caucasus (Olfert *et al*., 2006). Plant damage is caused by larval feeding; symptoms include misshapen plants and the for‐ mation of galls on leaves and flowers (Bardner et al., 1971). The larval stage overwinters in the soil, adults emerge in May and females lay eggs, in clusters of 2–50, on the surface of actively growing plants. Larvae feed on actively growing stems, leaves, and flowers, then drop to the soil to pupate. During the growing season, adults can emerge within 2 weeks or larvae enter diapause in autumn. Depending on temperature and soil moisture, *C. nasturtii* may have 2–5 generations (Hallett and Heal, 2001). Temperature and moisture have been identified to be the two most important factors responsible for population distribution, growth, and control. Population growth was greatest in warm, moist seasons and reduced in cool or dry seasons (Readshaw, 1966).

The Swede midge is a pest of most cultivated Brassicaceae such as broccoli, canola, cauliflower, cabbage, and Brussels sprouts. The

2006). Plant damage is caused by larval feeding; symptoms include misshapen plants and the formation of galls on leaves and

In 2004, the occurrence of Swede midge on four locations in Slovenia (Ljubljana, Rakitnica, Zakl near Braslovče, Škocjan near Koper) was investigated (Figure 5). Pheromone traps of the Swiss producer (Agroscope FAW, Wädenswill) were set in fields with Brassica plants. The aim of the research was to determine a population dynamics of the pest in vegetation period, to establish the number of generations it develops per year in geographically and cli‐ matically different regions. Understanding of the pest bionomics would help to set a strat‐ egy for control of Swede midge in Brassica plants. The results of the monitoring indicate that the species has 4 generations per year, also in the continental part of the country. In all four locations a generation was also established in September (Trdan et al., 2005a). Part of this research was published by Walland in 2007.

In similar research, which lasted from the beginning of April to the beginning of November 2006, a seasonal dynamics of Swede midge was investigated at the Laboratory Field of the Biotechnical Faculty in Ljubljana (Trdan and Bobnar, 2007; Trdan *et al*., 2008). The males of Swede midge were trapped with already mentioned traps of Swiss producer The phero‐ mone capsules were changed in 4-week intervals, while the males were counted on about every 7th day. The first massive occurrence of Swede midge (0.4 males/trap/day) was estab‐ lished in the 2nd decade of May, while the highest number of males (8/trap/day) were caught in the 2nd decade of July. In the 3rd decade of October, the last adults were found in the traps. Based on the results of monitoring we ascertained that in the central Slovenia the Swede midge has 3-4 generations. number of generations it develops per year in geographically and climatically different regions. Understanding of the pest bionomics would help to set a strategy for control of Swede midge in Brassica plants. The results of the monitoring indicate that the species has 4 generations per year, also in the continental part of the country. In all four locations a generation was also established in September (Trdan et al., 2005a). Part of this research was published by Walland in 2007. In similar research, which lasted from the beginning of April to the beginning of November 2006, a seasonal dynamics of Swede midge was investigated at the Laboratory Field of the Biotechnical Faculty in Ljubljana (Trdan and Bobnar, 2007; Trdan *et al*., 2008). The males of Swede midge were trapped with already mentioned traps of Swiss producer The pheromone capsules were changed in 4-week intervals, while the males were counted on about every 7th day. The first massive occurrence of Swede midge (0.4

larvae feed on the lower leaf surface 62-78 % of the time, chewing irregular patches in the leaves (Harcourt, 1957). All the leaf tissues are consumed except the veins. On some leaves, the larvae feed on all but the upper epidermis creating a "windowing" effect. The last stage larva is a voracious feeder; it causes more injury than the first three larval instars. Total de‐ velopment time from the egg to pupal stage averages 25 to 30 days, depending on weather, with a range of about 17 to 51 days. The number of generations varies from four in cold cli‐ mates to eight to 12 in the south. Overwintering survival is positively correlated with the

Research on Seasonal Dynamics of 14 Different Insects Pests in Slovenia Using Pheromone Traps

From the beginning of April to the beginning of November 2006, a seasonal dynamics of di‐ amondback moth was investigated at the Laboratory Field of the Biotechnical Faculty in Ljubljana. The males were trapped with the Hungarian traps type RAG (Plant Protection In‐ stitute, Hungarian Academy of Sciences). The pheromone capsules were changed in 4-week intervals, while the males were counted on about every 7th day. The first massive occurrence of diamondback moth (1.6 males/trap/day) was established in the 2nd decade of April, and the pest remained active until the 2nd decade of September (figure 6). The adults were the most numerous in the period between the end of May to the middle of June, but even then their number did not exceed three males caught per day. Based on the results of monitoring we ascertained that in the central Slovenia the diamondback moth has 4 generations (Trdan

abundance of snowfall in northern climates (Eigenbrode and Shelton, 1990).

and Bobnar, 2007; Rešetič, 2008).

0 0.5 1 1.5 2 2.5 3

**No.**

**males/trap/day**

4 Apr ‐ 10 Apr 10 Apr ‐ 18 Apr 18 Apr ‐ 24 Apr 24 Apr ‐ 3 May 3 May ‐ 8 May

8 15 22 29 May ‐ 5 Jun

5 Jun ‐ 12 Jun 12 Jun ‐ 19 Jun 19 Jun ‐ 26 Jun 26 Jun ‐ 3 Jul

**Time interval**

3 Jul ‐ 10 Jul

10 Jul ‐ 17 Jul

Flea beetles (Coleoptera: Chrysomelidae) inhabit a wide range of environments where cru‐ ciferous plants grow, including fields, gardens, and uncultivated areas. Although flea bee‐ tles colonize crops every year, their population densities vary widely between years (Andersen et al., 2005). Flea beetles are univoltine. They overwinter as adults, usually out‐

17 Jul ‐ 24 Jul 24 Jul ‐ 31 Jul 31 Jul ‐ 7 Aug

> 7

17 23 28 Aug ‐ 4 Sep 4 Sep ‐ 11 Sep 11 Sep ‐ 18 Sep 18 Sep ‐ 25 Sep 25 Sep ‐ 2 Oct

Ljubljana

http://dx.doi.org/10.5772/53186

157

Aug ‐ 28 Aug

Aug ‐ 23 Aug

Aug ‐ 17 Aug

May ‐ 29 May

May ‐ 22 May

May ‐ 15 May

damage.

**No.**

**males/trap/day**

4 Apr ‐ 10 Apr 18 Apr ‐ 24 Apr 3 May ‐ 8 May

15

May ‐ 22 May

**5. Field crop pests** 

Figure 5. Population dynamics of *Plutella xylostella* males in Ljubljana in 2006.

**Figure 6.** Population dynamics of *Plutella xylostella* males in Ljubljana in 2006.

**4.3. Flea beetles (***Phyllotreta* **spp.; Coleoptera, Chrysomelidae)**

Figure 6. Population dynamics of *Phyllotreta* spp. males in Ljubljana in 2006.

29 May ‐ 5 Jun

12 Jun ‐ 19 Jun 26 Jun ‐ 3 Jul 10 Jul ‐ 17 Jul

**Time interval**

24 Jul ‐ 31 Jul

> 7

> Aug ‐ 17 Aug

that in Central Slovenia the pest under our investigation has 1-2 generation (firure 7).

**4.3. Flea beetles (***Phyllotreta* **spp.; Coleoptera, Chrysomelidae)** 

Flea beetles (Coleoptera: Chrysomelidae) inhabit a wide range of environments where cruciferous plants grow, including fields, gardens, and uncultivated areas. Although flea beetles colonize crops every year, their population densities vary widely between years (Andersen et al., 2005). Flea beetles are univoltine. They overwinter as adults, usually outside fields, in margins, in hedgerows, and beneath shrubs, although some find shelter within fields in leaf litter, in stubble, or in grassy areas (Andersen et al., 2005)*.* Physical conditions at their overwintering sites may fluctuate daily, seasonally, and between years. Various species of flea beetle feed on the leaves of Brassica plants throughout the entire growing season (Vig, 2002; Trdan et al., 2005b; Bohinc et al., 2012). The beetles usually cause most problems on young plants, as these are small and hence, can tolerate only small amounts of

From the beginning of April until the beginning of November 2006, a seasonal dynamics of flea beetles was investigated in Ljubljana (Trdan and Bobnar, 2007; Kržišnik, 2009). The number of males was monitored with pheromone traps (type KLP+) of Hungarian producer. Pheromone baits were changed once per month, and the males which were caught in the traps were counted once per week. The beetles were the most numerous in the second and third ten-days period of July, while the last flea beetle was found in the beginning of November. Weather conditions in the growth period of cabbage, above all the rainfall and air temperature, had important influence on the number of the beetles. Based on the results of flea beetles monitoring we can conclude

23 4 Sep ‐ 11 Sep 18 Sep ‐ 25 Sep 2 Oct ‐ 9 Oct 16 Oct ‐ 23 Oct 30 Oct ‐ 6 Nov Ljubljana

Aug ‐ 28 Aug

In a related research, which was performed in 2006 (Bohinc, 2008), it was confirmed, that the use of synthetic insecticides and fungicides have an influence on a population dynamics of the above mentioned pest. males/trap/day) was established in the 2nd decade of May, while the highest number of males (8/trap/day) were caught in the 2nd decade of July. In the 3rd decade of October, the last adults were found in the traps. Based on the results of monitoring we ascertained that in the central Slovenia the Swede midge has 3-4 generations. In a related research, which was performed in 2006 (Bohinc, 2008), it was confirmed, that the use of synthetic insecticides and

fungicides have an influence on a population dynamics of the above mentioned pest.

Figure 4. Population dynamics of *Contarinia nasturtii* males in Ljubljana in 2004. **Figure 5.** Population dynamics of *Contarinia nasturtii* males in Ljubljana in 2004.

generations (Trdan and Bobnar, 2007; Rešetič, 2008).

#### **4.2. The diamondback moth (***Plutella xylostella* **[L.]; Lepidoptera, Plutellidae) 4.2. The diamondback moth (***Plutella xylostella* **[L.]; Lepidoptera, Plutellidae)**

include both cultivated and wild-growing plants of the family Cruciferae, as well as several ornamentals, such as wallflower, candytuft, stocks, and alyssum. Cultivated crops that are attacked include broccoli, Brussels sprouts, cabbage, cauliflower, Chinese broccoli, Chinese cabbage, flowering white cabbage, head cabbage, mustard cabbage and watercress. Weed hosts, such as mustard and radish, are important reservoir hosts for the species. The first instars sometimes feed in the spongy plant tissue beneath the leaf surface forming shallow mines that appear as numerous white marks. These mines are usually not longer than the length of the body. The larvae are surface feeders in all subsequent stages. These larvae feed on the lower leaf surface 62-78 % of the time, chewing irregular patches in the leaves (Harcourt, 1957). All the leaf tissues are consumed except the veins. On some leaves, the larvae feed on all but the upper epidermis creating a "windowing" effect. The last stage larva is a voracious feeder; it causes more injury than the first three larval instars. Total The diamondback moth is a cosmopolitan species that probably originated in the Mediterra‐ nean region (Hardy, 1938). Host plants include both cultivated and wild-growing plants of the family Cruciferae, as well as several ornamentals, such as wallflower, candytuft, stocks, and alyssum. Cultivated crops that are attacked include broccoli, Brussels sprouts, cabbage, cauliflower, Chinese broccoli, Chinese cabbage, flowering white cabbage, head cabbage, mustard cabbage and watercress. Weed hosts, such as mustard and radish, are important reservoir hosts for the species.

The diamondback moth is a cosmopolitan species that probably originated in the Mediterranean region (Hardy, 1938). Host plants

From the beginning of April to the beginning of November 2006, a seasonal dynamics of diamondback moth was investigated at the Laboratory Field of the Biotechnical Faculty in Ljubljana. The males were trapped with the Hungarian traps type RAG (Plant Protection Institute, Hungarian Academy of Sciences). The pheromone capsules were changed in 4-week intervals, while the males were counted on about every 7th day. The first massive occurrence of diamondback moth (1.6 males/trap/day) was established in the 2nd decade of April, and the pest remained active until the 2nd decade of September (figure 6). The adults were the most numerous in the period between the end of May to the middle of June, but even then their number did not exceed three males caught per day. Based on the results of monitoring we ascertained that in the central Slovenia the diamondback moth has 4

development time from the egg to pupal stage averages 25 to 30 days, depending on weather, with a range of about 17 to 51 days. The number of generations varies from four in cold climates to eight to 12 in the south. Overwintering survival is positively correlated with the abundance of snowfall in northern climates (Eigenbrode and Shelton, 1990). The first instars sometimes feed in the spongy plant tissue beneath the leaf surface forming shallow mines that appear as numerous white marks. These mines are usually not longer than the length of the body. The larvae are surface feeders in all subsequent stages. These

larvae feed on the lower leaf surface 62-78 % of the time, chewing irregular patches in the leaves (Harcourt, 1957). All the leaf tissues are consumed except the veins. On some leaves, the larvae feed on all but the upper epidermis creating a "windowing" effect. The last stage larva is a voracious feeder; it causes more injury than the first three larval instars. Total de‐ velopment time from the egg to pupal stage averages 25 to 30 days, depending on weather, with a range of about 17 to 51 days. The number of generations varies from four in cold cli‐ mates to eight to 12 in the south. Overwintering survival is positively correlated with the abundance of snowfall in northern climates (Eigenbrode and Shelton, 1990).

In similar research, which lasted from the beginning of April to the beginning of November 2006, a seasonal dynamics of Swede midge was investigated at the Laboratory Field of the Biotechnical Faculty in Ljubljana (Trdan and Bobnar, 2007; Trdan *et al*., 2008). The males of Swede midge were trapped with already mentioned traps of Swiss producer The phero‐ mone capsules were changed in 4-week intervals, while the males were counted on about every 7th day. The first massive occurrence of Swede midge (0.4 males/trap/day) was estab‐ lished in the 2nd decade of May, while the highest number of males (8/trap/day) were caught in the 2nd decade of July. In the 3rd decade of October, the last adults were found in the traps. Based on the results of monitoring we ascertained that in the central Slovenia the Swede

number of generations it develops per year in geographically and climatically different regions. Understanding of the pest bionomics would help to set a strategy for control of Swede midge in Brassica plants. The results of the monitoring indicate that the species has 4 generations per year, also in the continental part of the country. In all four locations a generation was also established

In similar research, which lasted from the beginning of April to the beginning of November 2006, a seasonal dynamics of Swede midge was investigated at the Laboratory Field of the Biotechnical Faculty in Ljubljana (Trdan and Bobnar, 2007; Trdan *et al*., 2008). The males of Swede midge were trapped with already mentioned traps of Swiss producer The pheromone capsules were changed in 4-week intervals, while the males were counted on about every 7th day. The first massive occurrence of Swede midge (0.4 males/trap/day) was established in the 2nd decade of May, while the highest number of males (8/trap/day) were caught in the 2nd decade of July. In the 3rd decade of October, the last adults were found in the traps. Based on the results of monitoring we

In a related research, which was performed in 2006 (Bohinc, 2008), it was confirmed, that the use of synthetic insecticides and

In a related research, which was performed in 2006 (Bohinc, 2008), it was confirmed, that the use of synthetic insecticides and fungicides have an influence on a population dynamics of

in September (Trdan et al., 2005a). Part of this research was published by Walland in 2007.

ascertained that in the central Slovenia the Swede midge has 3-4 generations.

156 Insecticides - Development of Safer and More Effective Technologies

Figure 4. Population dynamics of *Contarinia nasturtii* males in Ljubljana in 2004.

**Figure 5.** Population dynamics of *Contarinia nasturtii* males in Ljubljana in 2004.

and radish, are important reservoir hosts for the species.

generations (Trdan and Bobnar, 2007; Rešetič, 2008).

**4.2. The diamondback moth (***Plutella xylostella* **[L.]; Lepidoptera, Plutellidae)** 

The diamondback moth is a cosmopolitan species that probably originated in the Mediterra‐ nean region (Hardy, 1938). Host plants include both cultivated and wild-growing plants of the family Cruciferae, as well as several ornamentals, such as wallflower, candytuft, stocks, and alyssum. Cultivated crops that are attacked include broccoli, Brussels sprouts, cabbage, cauliflower, Chinese broccoli, Chinese cabbage, flowering white cabbage, head cabbage, mustard cabbage and watercress. Weed hosts, such as mustard and radish, are important

The first instars sometimes feed in the spongy plant tissue beneath the leaf surface forming shallow mines that appear as numerous white marks. These mines are usually not longer than the length of the body. The larvae are surface feeders in all subsequent stages. These

**4.2. The diamondback moth (***Plutella xylostella* **[L.]; Lepidoptera, Plutellidae)**

correlated with the abundance of snowfall in northern climates (Eigenbrode and Shelton, 1990).

The diamondback moth is a cosmopolitan species that probably originated in the Mediterranean region (Hardy, 1938). Host plants include both cultivated and wild-growing plants of the family Cruciferae, as well as several ornamentals, such as wallflower, candytuft, stocks, and alyssum. Cultivated crops that are attacked include broccoli, Brussels sprouts, cabbage, cauliflower, Chinese broccoli, Chinese cabbage, flowering white cabbage, head cabbage, mustard cabbage and watercress. Weed hosts, such as mustard

The first instars sometimes feed in the spongy plant tissue beneath the leaf surface forming shallow mines that appear as numerous white marks. These mines are usually not longer than the length of the body. The larvae are surface feeders in all subsequent stages. These larvae feed on the lower leaf surface 62-78 % of the time, chewing irregular patches in the leaves (Harcourt, 1957). All the leaf tissues are consumed except the veins. On some leaves, the larvae feed on all but the upper epidermis creating a "windowing" effect. The last stage larva is a voracious feeder; it causes more injury than the first three larval instars. Total development time from the egg to pupal stage averages 25 to 30 days, depending on weather, with a range of about 17 to 51 days. The number of generations varies from four in cold climates to eight to 12 in the south. Overwintering survival is positively

From the beginning of April to the beginning of November 2006, a seasonal dynamics of diamondback moth was investigated at the Laboratory Field of the Biotechnical Faculty in Ljubljana. The males were trapped with the Hungarian traps type RAG (Plant Protection Institute, Hungarian Academy of Sciences). The pheromone capsules were changed in 4-week intervals, while the males were counted on about every 7th day. The first massive occurrence of diamondback moth (1.6 males/trap/day) was established in the 2nd decade of April, and the pest remained active until the 2nd decade of September (figure 6). The adults were the most numerous in the period between the end of May to the middle of June, but even then their number did not exceed three males caught per day. Based on the results of monitoring we ascertained that in the central Slovenia the diamondback moth has 4

fungicides have an influence on a population dynamics of the above mentioned pest.

midge has 3-4 generations.

the above mentioned pest.

**No.**

**males/trap/day**

27 May ‐ 3 Jun

reservoir hosts for the species.

3 Jun ‐ 9 Jun 9 Jun ‐ 17 Jun 17 Jun ‐ 24 Jun 24 Jun ‐ 30 Jun 30 Jun ‐ 7 Jul

7 Jul ‐ 15 Jul 15 Jul ‐ 22 Jul 22 Jul ‐ 28 Jul 28 Jul ‐ 9 Aug

> 9

16 23

**Time interval**

31 Aug ‐ 6 Sep 6 Sep ‐ 13 Sep 13 Sep ‐ 20 Sep 20 Sep ‐ 27 Sep 27 Sep ‐ 4 Oct

4 Oct ‐ 11 Oct 11 Oct ‐ 18 Oct 18 Oct ‐ 25 Oct 25 Oct ‐ 4 Nov 4 Nov ‐ 9 Nov

9 16

Nov ‐ 25 Nov Ljubljana

Nov ‐ 16 Nov

Aug ‐ 31 Aug

Aug ‐ 23 Aug

Aug ‐ 16 Aug From the beginning of April to the beginning of November 2006, a seasonal dynamics of di‐ amondback moth was investigated at the Laboratory Field of the Biotechnical Faculty in Ljubljana. The males were trapped with the Hungarian traps type RAG (Plant Protection In‐ stitute, Hungarian Academy of Sciences). The pheromone capsules were changed in 4-week intervals, while the males were counted on about every 7th day. The first massive occurrence of diamondback moth (1.6 males/trap/day) was established in the 2nd decade of April, and the pest remained active until the 2nd decade of September (figure 6). The adults were the most numerous in the period between the end of May to the middle of June, but even then their number did not exceed three males caught per day. Based on the results of monitoring we ascertained that in the central Slovenia the diamondback moth has 4 generations (Trdan and Bobnar, 2007; Rešetič, 2008).

Figure 5. Population dynamics of *Plutella xylostella* males in Ljubljana in 2006. **Figure 6.** Population dynamics of *Plutella xylostella* males in Ljubljana in 2006.

Figure 6. Population dynamics of *Phyllotreta* spp. males in Ljubljana in 2006.

29 May ‐ 5 Jun

12 Jun ‐ 19 Jun

26 Jun ‐ 3 Jul 10 Jul ‐ 17 Jul

**Time interval**

24 Jul ‐ 31 Jul

> 7

> Aug ‐ 17 Aug

that in Central Slovenia the pest under our investigation has 1-2 generation (firure 7).

damage.

**No.**

**males/trap/day**

4 Apr ‐ 10 Apr 18 Apr ‐ 24 Apr 3 May ‐ 8 May

15

May ‐ 22 May

**5. Field crop pests** 

#### **4.3. Flea beetles (***Phyllotreta* **spp.; Coleoptera, Chrysomelidae)**

**4.3. Flea beetles (***Phyllotreta* **spp.; Coleoptera, Chrysomelidae)** 

gardens, and uncultivated areas. Although flea beetles colonize crops every year, their population densities vary widely between years (Andersen et al., 2005). Flea beetles are univoltine. They overwinter as adults, usually outside fields, in margins, in hedgerows, and beneath shrubs, although some find shelter within fields in leaf litter, in stubble, or in grassy areas (Andersen et al., 2005)*.* Physical conditions at their overwintering sites may fluctuate daily, seasonally, and between years. Various species of flea beetle feed on the leaves of Brassica plants throughout the entire growing season (Vig, 2002; Trdan et al., 2005b; Bohinc et al., 2012). The beetles usually cause most problems on young plants, as these are small and hence, can tolerate only small amounts of Flea beetles (Coleoptera: Chrysomelidae) inhabit a wide range of environments where cru‐ ciferous plants grow, including fields, gardens, and uncultivated areas. Although flea bee‐ tles colonize crops every year, their population densities vary widely between years (Andersen et al., 2005). Flea beetles are univoltine. They overwinter as adults, usually out‐

Flea beetles (Coleoptera: Chrysomelidae) inhabit a wide range of environments where cruciferous plants grow, including fields,

From the beginning of April until the beginning of November 2006, a seasonal dynamics of flea beetles was investigated in Ljubljana (Trdan and Bobnar, 2007; Kržišnik, 2009). The number of males was monitored with pheromone traps (type KLP+) of Hungarian producer. Pheromone baits were changed once per month, and the males which were caught in the traps were counted once per week. The beetles were the most numerous in the second and third ten-days period of July, while the last flea beetle was found in the beginning of November. Weather conditions in the growth period of cabbage, above all the rainfall and air temperature, had important influence on the number of the beetles. Based on the results of flea beetles monitoring we can conclude

23 4 Sep ‐ 11 Sep 18 Sep ‐ 25 Sep 2 Oct ‐ 9 Oct 16 Oct ‐ 23 Oct 30 Oct ‐ 6 Nov Ljubljana

Aug ‐ 28 Aug 3 May ‐ 8 May

8 15 22 29 May ‐ 5 Jun

5 Jun ‐ 12 Jun 12 Jun ‐ 19 Jun 19 Jun ‐ 26 Jun 26 Jun ‐ 3 Jul

**Time interval**

3 Jul ‐ 10 Jul

10 Jul ‐ 17 Jul

17 Jul ‐ 24 Jul 24 Jul ‐ 31 Jul 31 Jul ‐ 7 Aug

> 7

17 23 28 Aug ‐ 4 Sep 4 Sep ‐ 11 Sep 11 Sep ‐ 18 Sep 18 Sep ‐ 25 Sep 25 Sep ‐ 2 Oct

Ljubljana

threads. In spring and in the beginning of summer, they mine leaves, usually along main veins, also piercing holes in petioles. The damaged leaves roll and blacken. A black clump of rotten leaves fastened with silk threads is formed instead of the central rosette. In hot and dry years, such damage frequently causes the whole plant to die since the outer leaves die off quickly and new ones are not formed because of the central rosette loss. Caterpillars of the following generations penetrate into roots. In the upper part of the roots they gnaw out narrow, twisting grooves or holes under thin skin, sometimes boring to a depth of 5 cm. These holes under skin also injure lateral parts of roots. The damaged roots become languid and rotten. In parent beet plants, the caterpillars injure flower buds, unripe seeds, and tips of growing floriferous stalks, piercing holes; as a result, the stalks are bent, and yield of seeds sharply falls (Robert and Blaisinger, 1978). The economic damage threshold is exceed‐

Beet moth is a dangerous pest of sugar beet especially in southern Europe (Robert and Blaisinger, 1978). Caterpillars can also feed on other plants of the family Chenopodiaceae (pigweed, seablite, saltwort etc.). The caterpillars skeletonize leaves, braiding them with silk threads. In spring and in the beginning of summer, they mine leaves, usually along main veins, also piercing holes in petioles. The damaged leaves roll and blacken. A black clump of rotten leaves fastened with silk threads is formed instead of the central rosette. In hot and dry years, such damage frequently causes the whole plant to die since the outer leaves die off quickly and new ones are not formed because of the central rosette loss. Caterpillars of the following generations penetrate into roots. In the upper part of the roots they gnaw out narrow, twisting grooves or holes under thin skin, sometimes boring to a depth of 5 cm. These holes under skin also injure lateral parts of roots. The damaged roots become languid and rotten. In parent beet plants, the caterpillars injure flower buds, unripe seeds, and tips of growing floriferous stalks, piercing holes; as a result, the stalks are bent, and yield of seeds sharply falls (Robert and Blaisinger, 1978). The economic damage threshold is exceeded when 4-5 larvae are

Research on Seasonal Dynamics of 14 Different Insects Pests in Slovenia Using Pheromone Traps

There are two to five generations a year depending on the climate. Moth flight after wintering begins in April, during shooting of beet in spring. One generation develops 40-65 days. The pest numbers increase in every following generation, reaching maximum

In the beginning of this century, the sugarbeet moth was a new pest of sugarbeet in Slovenia. The first noticeable occurrence of the pest was recorded in 2003, which was distinctively drier and warmer than an average year. Such weather conditions are especially suitable for this species. In 2004, monitoring of the pest was carried out on four locations: Cvetkovci, Rakičan, Gornji Lenart near Brežice and Kranj. The occurrence of the pest was determined by means of setting pheromone traps on the margins of the sugarbeet fields. The greatest number of sugarbeet moths was caught in traps in Gornji Lenart near Brežice, where sugarbeet was grown in close vicinity in 2003. In Kranj, there was no trace of the pest at all. Based on one-year results of the monitoring of the sugarbeet moth we came to a conclusion that in 2004 in Slovenia the pest had 2 generations (figure 8). The sugarbeet moth has caused no severe yield loss in Slovenia so far. Consequently, no insecticides have been registered for its control as yet (Valič et al., 2005; Čepin, 2006). After 2006, the production of sugarbeet has stopped in Slovenia, and that is also one of the reasons that the pest

by the end of summer. This species overwinters as a pupa or partly-grown larva (Robert and Blaisinger, 1978).

This species overwinters as a pupa or partly-grown larva (Robert and Blaisinger, 1978).

There are two to five generations a year depending on the climate. Moth flight after wintering begins in April, during shooting of beet in spring. One generation develops 40-65 days. The pest numbers increase in every following generation, reaching maximum by the end of summer.

In the beginning of this century, the sugarbeet moth was a new pest of sugarbeet in Sloven‐ ia. The first noticeable occurrence of the pest was recorded in 2003, which was distinctively drier and warmer than an average year. Such weather conditions are especially suitable for this species. In 2004, monitoring of the pest was carried out on four locations: Cvetkovci, Ra‐ kičan, Gornji Lenart near Brežice and Kranj. The occurrence of the pest was determined by means of setting pheromone traps on the margins of the sugarbeet fields. The greatest num‐ ber of sugarbeet moths was caught in traps in Gornji Lenart near Brežice, where sugarbeet

was not recorded in the fodder beet field in the vicinity of Škoflja Loka during monitoring in 2010 (Dolenec, 2012).

**5.2. The turnip moth (***Agrotis segetum* **[Denis & Schiffermüller]; Lepidoptera, Noctuidae)** 

The turnip moth is distributed across the European and the Mediterranean regions. *Agrotis segetum* is an important economic insect of turnip, lettuce, Swedes, wild-growing plants, couch grass, bindweed and plantain. Infestation also occurs in neighbouring

The adult has a 40 mm wingspan; dark brown fore wings with, in the middle, a uniform spot and a clearer circular spot. The hind wings are white in the male and grey in the female. The periphery of the wings bears a thin black border. Larva is 45 to 50 mm, reddish head and a greyish body with two parallel longitudinal lines in the middle region. On each segment, 2 small black spots at the front and two at the back, bearing a small bristle as well.The young caterpillar first nibbles the wild-growing plants and then

**5.1. Beet moth (***Scrobipalpa ocellatella* **Boyd; Lepidoptera, Gelechiidae)** 

ed when 4-5 larvae are found on 70% of plants (Valič et al., 2005).

Figure 7. Population dynamics of *Scrobipalpa ocellatella* males in Gornji Lenart near Brežice in 2004.

**Figure 8.** Population dynamics of *Scrobipalpa ocellatella* males in Gornji Lenart near Brežice in 2004.

**Time interval**

vegetables including red beet, potato, cereals, tobacco and vine (Wood et al., 2009).

found on 70% of plants (Valič et al., 2005).

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

**No.**

**males/trap/day**

18 Apr ‐ 1 May

1 15 29 12 Jun ‐ 26 Jun

26 Jun ‐ 10 Jul 10 Jul ‐ 1 Aug 1 Aug ‐ 7 Aug

7 21 Aug ‐ 4 Sep 4 Sep ‐ 18 Sep 18 Sep ‐ 2 Oct

Gornji Lenart near Brežice

http://dx.doi.org/10.5772/53186

159

Aug ‐ 21 Aug

May ‐ 12 Jun

May ‐ 29 May

May ‐ 15 May

Aug ‐ 28 Aug

Aug ‐ 23 Aug

Aug ‐ 17 Aug

May ‐ 29 May

May ‐ 22 May

May ‐ 15 May

Figure 5. Population dynamics of *Plutella xylostella* males in Ljubljana in 2006.

side fields, in margins, in hedgerows, and beneath shrubs, although some find shelter with‐ in fields in leaf litter, in stubble, or in grassy areas (Andersen et al., 2005). Physical conditions at their overwintering sites may fluctuate daily, seasonally, and between years. Various species of flea beetle feed on the leaves of Brassica plants throughout the entire growing season (Vig, 2002; Trdan et al., 2005b; Bohinc et al., 2012). The beetles usually cause most problems on young plants, as these are small and hence, can tolerate only small amounts of damage. **4.3. Flea beetles (***Phyllotreta* **spp.; Coleoptera, Chrysomelidae)**  Flea beetles (Coleoptera: Chrysomelidae) inhabit a wide range of environments where cruciferous plants grow, including fields, gardens, and uncultivated areas. Although flea beetles colonize crops every year, their population densities vary widely between years (Andersen et al., 2005). Flea beetles are univoltine. They overwinter as adults, usually outside fields, in margins, in hedgerows, and beneath shrubs, although some find shelter within fields in leaf litter, in stubble, or in grassy areas (Andersen et al., 2005)*.* Physical conditions at their overwintering sites may fluctuate daily, seasonally, and between years. Various species of flea beetle feed on the leaves of Brassica plants throughout the entire growing season (Vig, 2002; Trdan et al., 2005b; Bohinc et al., 2012). The beetles usually cause most problems on young plants, as these are small and hence, can tolerate only small amounts of

Figure 6. Population dynamics of *Phyllotreta* spp. males in Ljubljana in 2006. **Figure 7.** Population dynamics of *Phyllotreta* spp. males in Ljubljana in 2006.

From the beginning of April until the beginning of November 2006, a seasonal dynamics of flea beetles was investigated in Ljubljana (Trdan and Bobnar, 2007; Kržišnik, 2009). The number of males was monitored with pheromone traps (type KLP+) of Hungarian producer. Pheromone baits were changed once per month, and the males which were caught in the traps were counted once per week. The beetles were the most numerous in the second and third ten-days period of July, while the last flea beetle was found in the beginning of November. Weather conditions in the growth period of cabbage, above all the rainfall and air temperature, had important influence on the number of the beetles. Based on the results of flea beetles monitoring we can conclude that in Central Slovenia the pest under our investigation has 1-2 generation (firure 7). **5. Field crop pests**  From the beginning of April until the beginning of November 2006, a seasonal dynamics of flea beetles was investigated in Ljubljana (Trdan and Bobnar, 2007; Kržišnik, 2009). The number of males was monitored with pheromone traps (type KLP+) of Hungarian producer. Pheromone baits were changed once per month, and the males which were caught in the traps were counted once per week. The beetles were the most numerous in the second and third ten-days period of July, while the last flea beetle was found in the beginning of No‐ vember. Weather conditions in the growth period of cabbage, above all the rainfall and air temperature, had important influence on the number of the beetles. Based on the results of flea beetles monitoring we can conclude that in Central Slovenia the pest under our investi‐ gation has 1-2 generation (firure 7).

### **5. Field crop pests**

damage.

0 0.5 1 1.5 2 2.5 3

**No.**

**males/trap/day**

4 Apr ‐ 10 Apr 10 Apr ‐ 18 Apr 18 Apr ‐ 24 Apr 24 Apr ‐ 3 May

#### **5.1. Beet moth (***Scrobipalpa ocellatella* **Boyd; Lepidoptera, Gelechiidae)**

Beet moth is a dangerous pest of sugar beet especially in southern Europe (Robert and Blai‐ singer, 1978). Caterpillars can also feed on other plants of the family Chenopodiaceae (pig‐ weed, seablite, saltwort etc.). The caterpillars skeletonize leaves, braiding them with silk threads. In spring and in the beginning of summer, they mine leaves, usually along main veins, also piercing holes in petioles. The damaged leaves roll and blacken. A black clump of rotten leaves fastened with silk threads is formed instead of the central rosette. In hot and dry years, such damage frequently causes the whole plant to die since the outer leaves die off quickly and new ones are not formed because of the central rosette loss. Caterpillars of the following generations penetrate into roots. In the upper part of the roots they gnaw out narrow, twisting grooves or holes under thin skin, sometimes boring to a depth of 5 cm. These holes under skin also injure lateral parts of roots. The damaged roots become languid and rotten. In parent beet plants, the caterpillars injure flower buds, unripe seeds, and tips of growing floriferous stalks, piercing holes; as a result, the stalks are bent, and yield of seeds sharply falls (Robert and Blaisinger, 1978). The economic damage threshold is exceed‐ ed when 4-5 larvae are found on 70% of plants (Valič et al., 2005). **5.1. Beet moth (***Scrobipalpa ocellatella* **Boyd; Lepidoptera, Gelechiidae)**  Beet moth is a dangerous pest of sugar beet especially in southern Europe (Robert and Blaisinger, 1978). Caterpillars can also feed on other plants of the family Chenopodiaceae (pigweed, seablite, saltwort etc.). The caterpillars skeletonize leaves, braiding them with silk threads. In spring and in the beginning of summer, they mine leaves, usually along main veins, also piercing holes in petioles. The damaged leaves roll and blacken. A black clump of rotten leaves fastened with silk threads is formed instead of the central rosette. In hot and dry years, such damage frequently causes the whole plant to die since the outer leaves die off quickly and new ones are not formed because of the central rosette loss. Caterpillars of the following generations penetrate into roots. In the upper part of the roots they gnaw out narrow, twisting grooves or holes under thin skin, sometimes boring to a depth of 5 cm. These holes under skin also injure lateral parts of roots. The damaged roots become languid and rotten. In parent beet plants, the caterpillars injure flower buds, unripe seeds, and tips of growing floriferous stalks, piercing holes; as a result, the stalks are bent, and yield of seeds sharply falls (Robert and Blaisinger, 1978). The economic damage threshold is exceeded when 4-5 larvae are

side fields, in margins, in hedgerows, and beneath shrubs, although some find shelter with‐ in fields in leaf litter, in stubble, or in grassy areas (Andersen et al., 2005). Physical conditions at their overwintering sites may fluctuate daily, seasonally, and between years. Various species of flea beetle feed on the leaves of Brassica plants throughout the entire growing season (Vig, 2002; Trdan et al., 2005b; Bohinc et al., 2012). The beetles usually cause most problems on young plants, as these are small and hence, can tolerate only small

Flea beetles (Coleoptera: Chrysomelidae) inhabit a wide range of environments where cruciferous plants grow, including fields, gardens, and uncultivated areas. Although flea beetles colonize crops every year, their population densities vary widely between years (Andersen et al., 2005). Flea beetles are univoltine. They overwinter as adults, usually outside fields, in margins, in hedgerows, and beneath shrubs, although some find shelter within fields in leaf litter, in stubble, or in grassy areas (Andersen et al., 2005)*.* Physical conditions at their overwintering sites may fluctuate daily, seasonally, and between years. Various species of flea beetle feed on the leaves of Brassica plants throughout the entire growing season (Vig, 2002; Trdan et al., 2005b; Bohinc et al., 2012). The beetles usually cause most problems on young plants, as these are small and hence, can tolerate only small amounts of

From the beginning of April until the beginning of November 2006, a seasonal dynamics of flea beetles was investigated in Ljubljana (Trdan and Bobnar, 2007; Kržišnik, 2009). The number of males was monitored with pheromone traps (type KLP+) of Hungarian producer. Pheromone baits were changed once per month, and the males which were caught in the traps were counted once per week. The beetles were the most numerous in the second and third ten-days period of July, while the last flea beetle was found in the beginning of November. Weather conditions in the growth period of cabbage, above all the rainfall and air temperature, had important influence on the number of the beetles. Based on the results of flea beetles monitoring we can conclude

23 4 Sep ‐ 11 Sep 18 Sep ‐ 25 Sep 2 Oct ‐ 9 Oct 16 Oct ‐ 23 Oct 30 Oct ‐ 6 Nov Ljubljana

Aug ‐ 28 Aug

Figure 5. Population dynamics of *Plutella xylostella* males in Ljubljana in 2006.

Figure 6. Population dynamics of *Phyllotreta* spp. males in Ljubljana in 2006.

**Figure 7.** Population dynamics of *Phyllotreta* spp. males in Ljubljana in 2006.

29 May ‐ 5 Jun

12 Jun ‐ 19 Jun

26 Jun ‐ 3 Jul 10 Jul ‐ 17 Jul

**Time interval**

24 Jul ‐ 31 Jul

From the beginning of April until the beginning of November 2006, a seasonal dynamics of flea beetles was investigated in Ljubljana (Trdan and Bobnar, 2007; Kržišnik, 2009). The number of males was monitored with pheromone traps (type KLP+) of Hungarian producer. Pheromone baits were changed once per month, and the males which were caught in the traps were counted once per week. The beetles were the most numerous in the second and third ten-days period of July, while the last flea beetle was found in the beginning of No‐ vember. Weather conditions in the growth period of cabbage, above all the rainfall and air temperature, had important influence on the number of the beetles. Based on the results of flea beetles monitoring we can conclude that in Central Slovenia the pest under our investi‐

Beet moth is a dangerous pest of sugar beet especially in southern Europe (Robert and Blai‐ singer, 1978). Caterpillars can also feed on other plants of the family Chenopodiaceae (pig‐ weed, seablite, saltwort etc.). The caterpillars skeletonize leaves, braiding them with silk

7

Aug ‐ 17 Aug

that in Central Slovenia the pest under our investigation has 1-2 generation (firure 7).

**5.1. Beet moth (***Scrobipalpa ocellatella* **Boyd; Lepidoptera, Gelechiidae)**

**4.3. Flea beetles (***Phyllotreta* **spp.; Coleoptera, Chrysomelidae)** 

amounts of damage.

**No.**

**males/trap/day**

4 Apr ‐ 10 Apr 18 Apr ‐ 24 Apr 3 May ‐ 8 May

15

May ‐ 22 May

0 0.5 1 1.5 2 2.5 3

**No.**

**males/trap/day**

4 Apr ‐ 10 Apr 10 Apr ‐ 18 Apr 18 Apr ‐ 24 Apr 24 Apr ‐ 3 May 3 May ‐ 8 May

158 Insecticides - Development of Safer and More Effective Technologies

8 15 22 29 May ‐ 5 Jun

5 Jun ‐ 12 Jun 12 Jun ‐ 19 Jun 19 Jun ‐ 26 Jun

26 Jun ‐ 3 Jul

**Time interval**

3 Jul ‐ 10 Jul 10 Jul ‐ 17 Jul 17 Jul ‐ 24 Jul 24 Jul ‐ 31 Jul 31 Jul ‐ 7 Aug

> 7

17 23 28 Aug ‐ 4 Sep 4 Sep ‐ 11 Sep 11 Sep ‐ 18 Sep 18 Sep ‐ 25 Sep 25 Sep ‐ 2 Oct

Ljubljana

Aug ‐ 28 Aug

Aug ‐ 23 Aug

Aug ‐ 17 Aug

May ‐ 29 May

May ‐ 22 May

May ‐ 15 May

**5. Field crop pests** 

**5. Field crop pests**

gation has 1-2 generation (firure 7).

damage.

Figure 7. Population dynamics of *Scrobipalpa ocellatella* males in Gornji Lenart near Brežice in 2004. **Figure 8.** Population dynamics of *Scrobipalpa ocellatella* males in Gornji Lenart near Brežice in 2004.

vegetables including red beet, potato, cereals, tobacco and vine (Wood et al., 2009).

found on 70% of plants (Valič et al., 2005).

There are two to five generations a year depending on the climate. Moth flight after wintering begins in April, during shooting of beet in spring. One generation develops 40-65 days. The pest numbers increase in every following generation, reaching maximum by the end of summer. This species overwinters as a pupa or partly-grown larva (Robert and Blaisinger, 1978). In the beginning of this century, the sugarbeet moth was a new pest of sugarbeet in Slovenia. The first noticeable occurrence of the pest was recorded in 2003, which was distinctively drier and warmer than an average year. Such weather conditions are especially There are two to five generations a year depending on the climate. Moth flight after wintering begins in April, during shooting of beet in spring. One generation develops 40-65 days. The pest numbers increase in every following generation, reaching maximum by the end of summer. This species overwinters as a pupa or partly-grown larva (Robert and Blaisinger, 1978).

suitable for this species. In 2004, monitoring of the pest was carried out on four locations: Cvetkovci, Rakičan, Gornji Lenart near

The turnip moth is distributed across the European and the Mediterranean regions. *Agrotis segetum* is an important economic insect of turnip, lettuce, Swedes, wild-growing plants, couch grass, bindweed and plantain. Infestation also occurs in neighbouring

The adult has a 40 mm wingspan; dark brown fore wings with, in the middle, a uniform spot and a clearer circular spot. The hind wings are white in the male and grey in the female. The periphery of the wings bears a thin black border. Larva is 45 to 50 mm, reddish head and a greyish body with two parallel longitudinal lines in the middle region. On each segment, 2 small black spots at the front and two at the back, bearing a small bristle as well.The young caterpillar first nibbles the wild-growing plants and then

Brežice and Kranj. The occurrence of the pest was determined by means of setting pheromone traps on the margins of the sugarbeet fields. The greatest number of sugarbeet moths was caught in traps in Gornji Lenart near Brežice, where sugarbeet was grown in close vicinity in 2003. In Kranj, there was no trace of the pest at all. Based on one-year results of the monitoring of the sugarbeet moth we came to a conclusion that in 2004 in Slovenia the pest had 2 generations (figure 8). The sugarbeet moth has caused no severe yield loss in Slovenia so far. Consequently, no insecticides have been registered for its control as yet (Valič et al., 2005; Čepin, 2006). After 2006, the production of sugarbeet has stopped in Slovenia, and that is also one of the reasons that the pest was not recorded in the fodder beet field in the vicinity of Škoflja Loka during monitoring in 2010 (Dolenec, 2012). **5.2. The turnip moth (***Agrotis segetum* **[Denis & Schiffermüller]; Lepidoptera, Noctuidae)**  In the beginning of this century, the sugarbeet moth was a new pest of sugarbeet in Sloven‐ ia. The first noticeable occurrence of the pest was recorded in 2003, which was distinctively drier and warmer than an average year. Such weather conditions are especially suitable for this species. In 2004, monitoring of the pest was carried out on four locations: Cvetkovci, Ra‐ kičan, Gornji Lenart near Brežice and Kranj. The occurrence of the pest was determined by means of setting pheromone traps on the margins of the sugarbeet fields. The greatest num‐ ber of sugarbeet moths was caught in traps in Gornji Lenart near Brežice, where sugarbeet

was grown in close vicinity in 2003. In Kranj, there was no trace of the pest at all. Based on one-year results of the monitoring of the sugarbeet moth we came to a conclusion that in 2004 in Slovenia the pest had 2 generations (figure 8). The sugarbeet moth has caused no se‐ vere yield loss in Slovenia so far. Consequently, no insecticides have been registered for its control as yet (Valič et al., 2005; Čepin, 2006). After 2006, the production of sugarbeet has stopped in Slovenia, and that is also one of the reasons that the pest was not recorded in the fodder beet field in the vicinity of Škoflja Loka during monitoring in 2010 (Dolenec, 2012).

cel on each location) where sugarbeet was sowed. Pheromone capsules were replaced once a month and the butterflies captured in them were counted in 2-3 week intervals. We ascer‐ tained that, under favourable climatic conditions, the turnip moth are able to overmultiply; that occurs when the air temperature rises above 12°C. The amount of rainfall does not in‐ fluence the bionomics of the pest. In the neighbouring countries turnip moth develops two generations per year. Based on our observations in 2004 turnip moth appears in two genera‐ tions also in Slovenia (figure 9). Similar conclusions were gained also in two researches, which took place in the vicinity of Škofja Loka; Kalan (2010), monitored the pest in 2008 on the corn field, and Dolenec (2012) studied the seasonal dynamics of the butterfly in 2010 on the fodder beet field. On the other side Srebernjak (2009) confirmed the occurrence of three

Research on Seasonal Dynamics of 14 Different Insects Pests in Slovenia Using Pheromone Traps

http://dx.doi.org/10.5772/53186

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generations of the same pest on the corn field in the vicinity of Novo mesto.

Adults are present from late May to September (Polesny et al., 2000).

fruits such as plum that mature in mid- to late summer (Hrdy et al., 1996).

**6.1. The Plum Fruit Moth (***Grapholita funebrana* **[Treitschke]; Lepidoptera, Tortricidae)**

A native of Europe, *Grapholita funebrana* has spread to most other fruit-growing regions of the Palaearctic. It is currently present from Europe and northern Africa across Asia Minor and Central Asia to China, Korea, and Japan (Hrdy et al., 1996). *Grapholita funebrana* is one of the most important lepidopteran pests of fruit in Europe. Larvae can cause significant dam‐ age to apricot, cherry, peach, plum, and other *Prunus* species. The Plum Fruit Moth com‐ pletes 1-3 generations per year; two generations are most common over most of its range.

First generation females lay eggs singly on fruitlets. Second generation females lay eggs near the base of maturing fruit. Larvae tunnel into the fruit and feed inside. Last instar larvae bore out of the fruit and overwinter in a cocoon spun on tree bark or in the soil. Pupation occurs the following spring. Larvae of the second generation cause the most damage to

Distribution of plum fruit moth in plum crowns and its apperance in the vicinity of the trees was investigated in 2007 in Dolenja vas near Ribnica (Pogorelc, 2008). Pheromone traps were placed in the first half of February on two trees. Experiment has lasted till the end of Sep‐ tember. The purpose of experiment was to find out in which parts of the crowns or how far from the trees the pest appears. It was found out that pest was the most abundant at sunny exposure of crowns, on SE and SW crown parts. Inside of crowns and in northern part of crowns, the pest was less abundant. Before the flowering of plums the abundance of the plum fruit moth in plum crowns and in the vicinity of the trees was almost same numbers. During the flowering and growing season, the number of the moths was higher inside crowns. Plum fruit moth appeared also in the vicinity of the trees. On baits, 10 and 20 m away of them, quite high number of the males has been caught. Air temperature and amount of rain also influenced moth apperance. From the data of our research we can con‐ clude that pest had two generations per year (figure 10), whose the second generation was more abundant from the first generation. In a related research Humski et al. (2005) and

**6. Fruit tree and grapevine pests**

#### **5.2. The turnip moth (***Agrotis segetum* **[Denis & Schiffermüller]; Lepidoptera, Noctuidae)**

The turnip moth is distributed across the European and the Mediterranean regions. *Agrotis segetum* is an important economic insect of turnip, lettuce, Swedes, wild-growing plants, couch grass, bindweed and plantain. Infestation also occurs in neighbouring vegetables in‐ cluding red beet, potato, cereals, tobacco and vine (Wood et al., 2009).

The adult has a 40 mm wingspan; dark brown fore wings with, in the middle, a uniform spot and a clearer circular spot. The hind wings are white in the male and grey in the fe‐ male. The periphery of the wings bears a thin black border. Larva is 45 to 50 mm, reddish head and a greyish body with two parallel longitudinal lines in the middle region. On each segment, 2 small black spots at the front and two at the back, bearing a small bristle as well.The young caterpillar first nibbles the wild-growing plants and then attacks the neigh‐ bouring cultivated species. It feeds at night, gnawing the foliage and cutting the petioles. During the day, it conceals itself by rolling up under a lump of earth or at a slight depth in the ground (Anderson and Löfquist, 1996). attacks the neighbouring cultivated species. It feeds at night, gnawing the foliage and cutting the petioles. During the day, it

conceals itself by rolling up under a lump of earth or at a slight depth in the ground (Anderson and Löfquist, 1996).

Figure 8. Population dynamics of *Agrotis segetum* males in Rakičan in 2004. **Figure 9.** Population dynamics of *Agrotis segetum* males in Rakičan in 2004.

same pest on the corn field in the vicinity of Novo mesto.

mature in mid- to late summer (Hrdy et al., 1996).

6. Fruit tree and grapevine pests

In 2004, the monitoring of turnip moth in sugarbeet (*Beta vulgaris* var. *altissima* Döll.) were performed in two locations in Slovenia: Cvetkovci near Ormož, Rakičan and Kranj (Zalokar, 2006). Pheromone traps (VARL type, Csal♀m♂N® Budapest, Hungary) were used for monitoring the pest under investigation. Four baits were set along the margins of fields (one parcel on each location) where sugarbeet was sowed. Pheromone capsules were replaced once a month and the butterflies captured in them were counted in 2-3 week intervals. We ascertained that, under favourable climatic conditions, the turnip moth are able to overmultiply; that occurs when the air temperature rises above 12°C. The amount of rainfall does not influence the bionomics of the pest. In the In 2004, the monitoring of turnip moth in sugarbeet (*Beta vulgaris* var. *altissima* Döll.) were performed in two locations in Slovenia: Cvetkovci near Ormož, Rakičan and Kranj (Zalokar, 2006). Pheromone traps (VARL type, Csal♀m♂N® Budapest, Hungary) were used for mon‐ itoring the pest under investigation. Four baits were set along the margins of fields (one par‐

**6.1. The Plum Fruit Moth (***Grapholita funebrana* **[Treitschke]; Lepidoptera, Tortricidae)** 

are most common over most of its range. Adults are present from late May to September (Polesny et al., 2000).

neighbouring countries turnip moth develops two generations per year. Based on our observations in 2004 turnip moth appears in two generations also in Slovenia (figure 9). Similar conclusions were gained also in two researches, which took place in the vicinity of Škofja Loka; Kalan (2010), monitored the pest in 2008 on the corn field, and Dolenec (2012) studied the seasonal dynamics of the butterfly in 2010 on the fodder beet field. On the other side Srebernjak (2009) confirmed the occurrence of three generations of the

A native of Europe, *Grapholita funebrana* has spread to most other fruit-growing regions of the Palaearctic. It is currently present from Europe and northern Africa across Asia Minor and Central Asia to China, Korea, and Japan (Hrdy et al., 1996). *Grapholita funebrana* is one of the most important lepidopteran pests of fruit in Europe. Larvae can cause significant damage to apricot, cherry, peach, plum, and other *Prunus* species. The Plum Fruit Moth completes 1-3 generations per year; two generations

First generation females lay eggs singly on fruitlets. Second generation females lay eggs near the base of maturing fruit. Larvae tunnel into the fruit and feed inside. Last instar larvae bore out of the fruit and overwinter in a cocoon spun on tree bark or in the soil. Pupation occurs the following spring. Larvae of the second generation cause the most damage to fruits such as plum that cel on each location) where sugarbeet was sowed. Pheromone capsules were replaced once a month and the butterflies captured in them were counted in 2-3 week intervals. We ascer‐ tained that, under favourable climatic conditions, the turnip moth are able to overmultiply; that occurs when the air temperature rises above 12°C. The amount of rainfall does not in‐ fluence the bionomics of the pest. In the neighbouring countries turnip moth develops two generations per year. Based on our observations in 2004 turnip moth appears in two genera‐ tions also in Slovenia (figure 9). Similar conclusions were gained also in two researches, which took place in the vicinity of Škofja Loka; Kalan (2010), monitored the pest in 2008 on the corn field, and Dolenec (2012) studied the seasonal dynamics of the butterfly in 2010 on the fodder beet field. On the other side Srebernjak (2009) confirmed the occurrence of three generations of the same pest on the corn field in the vicinity of Novo mesto.
