**6.3** *Cylindrocopturus adspersus* **(LeConte) (Coleoptera: Curculionidae)**

**Identification:** Sunflower stem weevil adults are less than 4-5 mm long and grayish brown with white markings on the wing covers and thorax. The snout, eyes and antennae are black. Eggs are very small about 0.51 mm long by 0.33 mm wide, oval and yellow, and are difficult to see. Larvae are approximately 6 mm long at maturity. Larvae are legless and creamy white with a small, brown head capsule. They are normally in a curled or C-shaped. Pupae are similar in size to the adult and are creamy white (Knodel et al., n.d.).

**Life cycle and damage**: adult emerge from overwintered stalks or root crowns and mating occurs soon after emergence. Adults feed on stem and leaf tissues which causes minor damage to them. Females lay eggs individually in the stem tissue around the first node (cotyledon) or inside the epidermis of sunflower stems. First instar larvae feed on sub epidermal and vascular tissue in the stem. Feeding is concentrated in the pith tissue as the larvae develop to third and fourth instar stages. It has about five to seven larval instars. Larvae feed apically and last instars descend to the lower portion of the stalk or root crown and excavate overwintering chambers by chewing cavities into the stem cortex. They have only one generation per year. The stem may break, causing a loss of the entire head prior to harvest. Stalk lodging is most severe during drought stress or when high winds occur as plants are drying prior to harvest. Lodging typically occurs at or slightly above the soil line, in contrast to breakage attributed to stalk diseases. Lodging is a good indicator of larval densities; however, lodging is influenced by other factors, including stalk diameter, cortex and pith thickness of the stem, weight of sunflower heads, wind velocity and direction, position of larvae in overwintering chambers in the stalk (Knodel et al., n.d.).

**Monitoring:** monitor the field and count number of weevils. Adults can be found on both surfaces of the leaves, the lower portions of the stem, in leaf axils, within the dried cotyledons or in soil cracks at the base of the plant. Field scouting for adults should begin when plants are in the eight to 10 leaf stages. Five randomly sampling sites are determined 70-100 feet in from the field margin and in each sample site, five plants is selected. It is recommended to use an X pattern (or W pattern) to space sample sites throughout the entire field (Knodel et al., n.d.). According to the Michaud et al., (2011) scouting adults is really difficult and not recommended in many cases. So, in a region with a history of stem weevil problems growers may assume that any dry land sunflowers will be at risk, and that their impact on the crop will increase with adversity of growing conditions.

**Economic and action thresholds:** The economic threshold is one adult per three plants, or about 40 larvae per stalk at the end of the season (Knodel et al., n.d.).

**Control**: delayed planting and reducing plant population increases stalk diameter which is useful for controlling *C. adspersus* (Knodel et al., n.d.). Systemic pesticides such as carbofuran give simultaneous control of stem weevils and most other stem-infesting insects,

Oilseed Pests 167

stage, the plant becomes significantly dehydrated and encapsulation of the larvae within a soil cocoon begins. Larvae overwinter within the cocoon among the remaining roots in the soil and it has one generation per year (Knodel et al., n.d.). When larvae are exceptionally

**Economic and action thresholds:** No economic thresholds have been established for root

**Control**: There are currently no management recommendations for sunflower root weevil. However, growers should realize that significant burrowing in sunflower fields and numerous uprooted plants are often caused by mammals foraging for root weevil larvae

**Identification:** They are known as the gray seed weevil, and the red seed weevil, respectively. The gray seed weevil is about 8 mm long and pale gray, with a gently curving snout. Adults can frequently be found hiding under the bracts of sunflower buds either prior to or during bloom. *S. fulvus* is a small, reddish-brown weevil, about 3-4 mm long. Adults are most easily seen on the faces of blooming sunflowers feeding on pollen, or hiding behind the flower bracts. Infested seeds are not noticeably different from healthy ones, but display an exit hole near the top once the larva has matured and left (Michaud et al., 2011). **Life cycle and damage**: *S. sordidus* females favor flowers in the late bud stage for oviposition, laying their eggs singly at the base of the developing seeds. Upon hatching, larvae bore into the seeds at their base, destroying the ovaries. At maturity, larvae exit the seeds and drop to the ground where they seek overwintering sites in the soil. The larvae feed within developing seeds and cause a galling response, leaving affected seeds swollen in appearance, but empty. Adult weevils of *S. fulvus* seek sunflowers in bloom and females must feed on pollen for at least four days before they can produce eggs. Females lay egg individually and directly into a seed and this requires a seed in the appropriate developmental stage. Developing larvae do not usually consume the seed completely, but significantly reduce kernel weight and oil content. The time frame of larval development is such that a percentage of larvae may still be present in seed at harvest, leading to temperature and moisture problems in storage. Larvae often can be found in seeds at harvest, especially when harvest is early, but most die in storage without causing further damage. They can result in yield reductions. However, the red seed weevil is more commonly responsible for economic damage than the gray seed weevil. Both of them have

**Monitoring:** monitoring should be done as the field approaches 85 % bloom, or when 80 % of plants are past the R4 stage. Count the number of weevils on the faces of five of the most mature flowers at each of five sites. This process can be facilitated by spraying the faces of each flower with a DEET-containing mosquito repellent that will cause weevils to quickly exit the flower. For more information refer to the monitoring section of *C. assimilis* in

**6.6** *Smicronyx sordidus* **(LeConte) and** *Smicronyx fulvus* **(LeConte) (Coleoptera:** 

abundant, they may cause plant wilting and lodging (Michaud et al., 2011).

**Monitoring:** monitoring is not so important for this pest species.

weevils.

(Michaud et al., 2011).

one generation per year (Michaud et al., 2011).

mustard (Michaud et al., 2011).

**Curculionidae)** 

and may also preserve stalk integrity by delaying processes of deterioration. Although seed treatments can be useful for improving seedling establishment, their duration of activity within the plant is not sufficient to provide control of stem weevils. Applying insecticides such as Beta-cyfluthrin, Chlorpyrifos, Chlorpyrifos plus gamma-cyhalothrin (Cobalt), Chlorpyrifos plus zeta-cypermethrin, Deltamethrin, Esfenvalerate, and Gamma-cyhalothrin (Proaxis) is recommended if the threshold is exceeded (Michaud et al., 2011).

#### **6.4** *Apion occidentale* **(Fall) (Coleoptera: Curculionidae)**

**Identification:** It is known as black sunflower stem weevil. Adults are shiny black and less than 3 mm long. The snout is very narrow and protrudes forward from the head, which is small in relation to the rather large, almost globosely body. Larvae are similar in appearance to the sunflower stem weevil larvae, except they are only 3 mm long at maturity and more yellow with a more pointed posterior (Knodel et al., n.d.).

**Life cycle and damage**: Adults overwinter in soil or plant residue; after they emerge they feed on leaf and stem tissue. Females lay eggs under the epidermis in leaf petioles or stems near leaf axils. Larvae feed in vascular and pith tissues of stems and petioles. Newly emerged larvae tunnel in the pith of the stem, pupate and emerge as adults. second generation adults feed on the leaves and stems of the plant, but as the plant matures and the leaves begin to die, adults move under the bracts of the sunflower head, where they can be observed feeding until the plants are harvested. Adults move into the soil to overwinter. Although feeding damage is seldom significant, however, this species has been associated with the transmission of the pathogen *Phoma macdonaldii* (Boerma), the causal agent of phoma black stem. Stand loss can occur where extremely high populations are feeding on sunflower seedlings. In most cases, however, populations are too low to cause economic damage, and stalk tunneling only results in minor injury to the plant (Knodel et al., n.d.).

**Monitoring:** refer to the monitoring section for *C. adspersus*.

**Economic and action thresholds:** no action threshold has been set for this species.

**Control**: This species, has not been considered as an economically important pest in cultivated sunflower fields. Controlling other pests such as *C. adspersus* appears to give simultaneous control of *A. occidentale*.

#### **6.5** *Baris strenua* **(LeConte) (Coleoptera: Curculionidae)**

**Identification:** Sunflower root weevil adults are rather robust weevils, with a somewhat oval-shaped body. Adults are dull black and 6 mm long with a short, almost blunt, downward projecting snout. Larvae are 6 mm long at maturity, legless, and have a white body with a small, brown head capsule (Knodel et al., n.d.).

**Life cycle and damage**: Adults feed on sunflower foliage in early morning and late afternoon. About two weeks after emergence, adults begin to congregate around the root zone near the soil surface. They continue feeding and mating occur during this period. Feeding activity produces callus tissue, under which the bright yellow eggs are deposited two or three at a time. First instar larvae are not very mobile and feed on the epidermal and cortical cells of the roots. Most feeding (consisting of circular tunnels) and development to fourth instar takes place in the same area where egg hatching occurs. In the fourth larval

and may also preserve stalk integrity by delaying processes of deterioration. Although seed treatments can be useful for improving seedling establishment, their duration of activity within the plant is not sufficient to provide control of stem weevils. Applying insecticides such as Beta-cyfluthrin, Chlorpyrifos, Chlorpyrifos plus gamma-cyhalothrin (Cobalt), Chlorpyrifos plus zeta-cypermethrin, Deltamethrin, Esfenvalerate, and Gamma-cyhalothrin

**Identification:** It is known as black sunflower stem weevil. Adults are shiny black and less than 3 mm long. The snout is very narrow and protrudes forward from the head, which is small in relation to the rather large, almost globosely body. Larvae are similar in appearance to the sunflower stem weevil larvae, except they are only 3 mm long at maturity and more

**Life cycle and damage**: Adults overwinter in soil or plant residue; after they emerge they feed on leaf and stem tissue. Females lay eggs under the epidermis in leaf petioles or stems near leaf axils. Larvae feed in vascular and pith tissues of stems and petioles. Newly emerged larvae tunnel in the pith of the stem, pupate and emerge as adults. second generation adults feed on the leaves and stems of the plant, but as the plant matures and the leaves begin to die, adults move under the bracts of the sunflower head, where they can be observed feeding until the plants are harvested. Adults move into the soil to overwinter. Although feeding damage is seldom significant, however, this species has been associated with the transmission of the pathogen *Phoma macdonaldii* (Boerma), the causal agent of phoma black stem. Stand loss can occur where extremely high populations are feeding on sunflower seedlings. In most cases, however, populations are too low to cause economic damage, and stalk tunneling only results in minor injury to the plant (Knodel et al., n.d.).

(Proaxis) is recommended if the threshold is exceeded (Michaud et al., 2011).

**6.4** *Apion occidentale* **(Fall) (Coleoptera: Curculionidae)** 

yellow with a more pointed posterior (Knodel et al., n.d.).

**Monitoring:** refer to the monitoring section for *C. adspersus*.

**6.5** *Baris strenua* **(LeConte) (Coleoptera: Curculionidae)** 

body with a small, brown head capsule (Knodel et al., n.d.).

simultaneous control of *A. occidentale*.

**Economic and action thresholds:** no action threshold has been set for this species.

**Control**: This species, has not been considered as an economically important pest in cultivated sunflower fields. Controlling other pests such as *C. adspersus* appears to give

**Identification:** Sunflower root weevil adults are rather robust weevils, with a somewhat oval-shaped body. Adults are dull black and 6 mm long with a short, almost blunt, downward projecting snout. Larvae are 6 mm long at maturity, legless, and have a white

**Life cycle and damage**: Adults feed on sunflower foliage in early morning and late afternoon. About two weeks after emergence, adults begin to congregate around the root zone near the soil surface. They continue feeding and mating occur during this period. Feeding activity produces callus tissue, under which the bright yellow eggs are deposited two or three at a time. First instar larvae are not very mobile and feed on the epidermal and cortical cells of the roots. Most feeding (consisting of circular tunnels) and development to fourth instar takes place in the same area where egg hatching occurs. In the fourth larval stage, the plant becomes significantly dehydrated and encapsulation of the larvae within a soil cocoon begins. Larvae overwinter within the cocoon among the remaining roots in the soil and it has one generation per year (Knodel et al., n.d.). When larvae are exceptionally abundant, they may cause plant wilting and lodging (Michaud et al., 2011).

**Monitoring:** monitoring is not so important for this pest species.

**Economic and action thresholds:** No economic thresholds have been established for root weevils.

**Control**: There are currently no management recommendations for sunflower root weevil. However, growers should realize that significant burrowing in sunflower fields and numerous uprooted plants are often caused by mammals foraging for root weevil larvae (Michaud et al., 2011).

#### **6.6** *Smicronyx sordidus* **(LeConte) and** *Smicronyx fulvus* **(LeConte) (Coleoptera: Curculionidae)**

**Identification:** They are known as the gray seed weevil, and the red seed weevil, respectively. The gray seed weevil is about 8 mm long and pale gray, with a gently curving snout. Adults can frequently be found hiding under the bracts of sunflower buds either prior to or during bloom. *S. fulvus* is a small, reddish-brown weevil, about 3-4 mm long. Adults are most easily seen on the faces of blooming sunflowers feeding on pollen, or hiding behind the flower bracts. Infested seeds are not noticeably different from healthy ones, but display an exit hole near the top once the larva has matured and left (Michaud et al., 2011).

**Life cycle and damage**: *S. sordidus* females favor flowers in the late bud stage for oviposition, laying their eggs singly at the base of the developing seeds. Upon hatching, larvae bore into the seeds at their base, destroying the ovaries. At maturity, larvae exit the seeds and drop to the ground where they seek overwintering sites in the soil. The larvae feed within developing seeds and cause a galling response, leaving affected seeds swollen in appearance, but empty. Adult weevils of *S. fulvus* seek sunflowers in bloom and females must feed on pollen for at least four days before they can produce eggs. Females lay egg individually and directly into a seed and this requires a seed in the appropriate developmental stage. Developing larvae do not usually consume the seed completely, but significantly reduce kernel weight and oil content. The time frame of larval development is such that a percentage of larvae may still be present in seed at harvest, leading to temperature and moisture problems in storage. Larvae often can be found in seeds at harvest, especially when harvest is early, but most die in storage without causing further damage. They can result in yield reductions. However, the red seed weevil is more commonly responsible for economic damage than the gray seed weevil. Both of them have one generation per year (Michaud et al., 2011).

**Monitoring:** monitoring should be done as the field approaches 85 % bloom, or when 80 % of plants are past the R4 stage. Count the number of weevils on the faces of five of the most mature flowers at each of five sites. This process can be facilitated by spraying the faces of each flower with a DEET-containing mosquito repellent that will cause weevils to quickly exit the flower. For more information refer to the monitoring section of *C. assimilis* in mustard (Michaud et al., 2011).

Oilseed Pests 169

**Identification:** Sunflower maggot is the only tephritid species found in the stalks of cultivated sunflowers. The showy yellow adult has a wing span of about 13 mm and a body length of 6 mm. The eyes are bright green and the wings bear broad dark bands that form a fairly distinct F pattern near the wing tip. Eggs are 1 mm long and are white and elongated. Larvae are yellow-white, headless and legless, tapered from anterior to posterior and

**Life cycle and damage**: Adults emerge and flies have been noted in shelterbelts and field margins. Females lay eggs singly in stem tissue near the apical meristem, and larvae feed in the stalk pith, creating large tunnels. The maggots, when fully developed, emerge from the stalk. Larvae develop through three instars in approximately six weeks. This species overwinters as a larva in plant debris in the soil. The sunflower maggot has one generation per year. Feeding is confined to the pith, which acts as a supporting structure, and is not critical to plant nutrition. Secondary fungal infections also are associated with tunneling by the larvae within the stalk. Stalks are not weakened and seed yield is not reduced, even with

**Monitoring:** no scouting methods have been established for sunflower maggot.

**Control**: controlling other pests of sunflower will manage maggot infestations.

**Economic and action thresholds:** no thresholds has been established for sunflower maggot.

**6.9** *Trichoplusia ni* **(Hübner)***, Thysanoplusia orichalcea* **(F.) (Lepidoptera: Noctuidae) Identification:** *T. ni* is known as cabbage loopers. Moths are dark, smoky, and gray variegated with light grayish brown. Characteristic small silvery oval spots and U-shaped silvery white marks are on the middle of the forewings. Hind wings are pale brown with the veins conspicuously visible. Males have tufts of gold hair at the tip of the abdomen. Eggs are hemispherical, pale green or white with shallow ridges that meet at the center of the egg. The newly emerged caterpillars are translucent white. Once feeding starts the larvae become pale green, with a thin white line running lengthwise down each side of the body and two white lines along the middle of the back. Pupae are yellow green with a few brown patches when newly formed and gradually darken to dark brown before adult emergence. The pupation occurs in white transparent silken cocoon in folded leaf (Mau et al., 2007). *T. orichalcea* is known as soybean looper, but larvae are an occasional pest of sunflower. The moth forewings are brown with a large, bright gold patch. Hind wings are fawn-colored, darkening towards the outer margins. The Eggs are pale yellow-green, ribbed and flat. Very small larvae are green all over but medium larvae usually have prominent dark and white striping. Larvae pupate under leaves in a thin silken cocoon. Pupae are dark above and pale

**Life cycle and damage**: females of *T. ni* lay eggs singly on the lower leaf surface near the leaf margin. Eggs hatch in 3-4 days. This is one of the major pests of sunflower. The young larvae feed on chlorophyll contents and make part of leaf transparent. As the larvae grown they feed on the leaf margins and during severe infestation only midribs are left. The presence of small transparent leaf spot, devoid of chlorophyll symbolizes the beginning of pest population. The caterpillar stage lasts for 12-20 days. The pupal stage lasts for 9 days

**6.8** *Strauzia longipennis* **(Wiedemann) (Diptera: Tephritidae)** 

approximately (7 mm) long at maturity (Knodel et al., n.d.).

severe pith destruction (Knodel et al., n.d.).

underneath (Brier, 2010).

**Economic and action thresholds:** No economic threshold has been established for the gray seed weevil and it is generally considered a less serious pest than the red seed weevil. Thresholds calculated for red seed weevil are sometimes used for gray seed weevil and control of gray seed weevil requires pesticide applications prior to bloom, when about 10- 15% of plants have reached the R4 stage. Generally, the threshold for oilseed sunflowers falls somewhere between 10 and 20 weevils per flower, but the threshold is much lower for confection sunflowers (usually 1 or 2 weevils per flower) because of industry standards that demand seed damage remain below 3-4 % of kernels. Research suggests that approximately 27 damaged kernels result for every adult weevil observed at the early bloom stage. An early treatment should be followed by continued scouting at 4-5 day intervals, as adult emergence continues over several weeks (Michaud et al., 2011).

**Control**: tillage has been shown to reduce survival of overwintering weevils. Chemical treatments are recommended if the threshold is exceeded. Beta-cyfluthrin (Baythroid XL); Chlorpyrifos; Chlorpyrifos plus gamma-cyhalothrin (Cobalt); Chlorpyrifos plus zetacypermethrin (Stallion); Deltamethrin (Delta Gold); Gamma-cyhalothrin (Proaxis); Lambdacyhalothrin, Parathion, methyl (Cheminova Methyl 4EC) are appropriate for controlling seed weevils (Michaud et al., 2011).

#### **6.7** *Pterohelaeus alternatus* **(Pascoe),** *Pterohelaeus darlingensis* **(Carter) and**  *Gonocephalum macleayi* **(Blackburn) (Coleoptera: Tenebrionidae)**

**Identification:** They are known as striate false wireworm, Eastern false wireworm and Southern false wireworm, respectively. Adult beetles of *Pterohelaeus* spp. are 20 mm long and dark grey-black with a distinctive 'pie-dish' shape formed by flanges around the outline of the beetle. Adults of *Gonocephalum* spp. are 9 mm long, dark grey-black and often covered in soil. There are flanges around the outline of the thorax (behind the head). Larvae are up to 30 mm long, shiny and cream, yellow or tan with three pairs of legs behind the head. They are hard-bodied, cylindrical and segmented with a rounded head (Murray, 2010).

**Life cycle and damage**: females lay eggs singly in moist soil, usually under trash or lowgrowing weeds. Both adults and larvae attack sunflower and damage of them may necessitate replanting. The larvae feed on decaying vegetable and crop residues in the soil; they also feed on newly germinating seed and the growing points of seedlings which results in patchy stands. Damage is most common in early-planted crops where crop residue has become scarce. They are major pests of seedling field crops and especially attack sunflower, soybeans, and mungbeans. They usually have one generation per year (Brien, 2011).

**Monitoring:** monitoring can be difficult; either hand sift 10 soil samples (30 x 30 cm) or place 10 germinating seed baits monitoring for soil-dwelling insects throughout the paddock. Pitfall traps can be used for counting the number of false wireworms (Brien, 2011).

**Economic and action thresholds:** The action threshold is observing more than 25 wireworm larvae in 20 germinating seed baits (Murray, 2010).

**Control**: Use of press wheels at planting; clean cultivation during summer can be effective against wireworms. Control of adults is obtained by baiting with insecticide-treated cracked and larvae can be controlled by insecticide applications at planting or insecticide-treated seed (Brien, 2011).

**Economic and action thresholds:** No economic threshold has been established for the gray seed weevil and it is generally considered a less serious pest than the red seed weevil. Thresholds calculated for red seed weevil are sometimes used for gray seed weevil and control of gray seed weevil requires pesticide applications prior to bloom, when about 10- 15% of plants have reached the R4 stage. Generally, the threshold for oilseed sunflowers falls somewhere between 10 and 20 weevils per flower, but the threshold is much lower for confection sunflowers (usually 1 or 2 weevils per flower) because of industry standards that demand seed damage remain below 3-4 % of kernels. Research suggests that approximately 27 damaged kernels result for every adult weevil observed at the early bloom stage. An early treatment should be followed by continued scouting at 4-5 day intervals, as adult

**Control**: tillage has been shown to reduce survival of overwintering weevils. Chemical treatments are recommended if the threshold is exceeded. Beta-cyfluthrin (Baythroid XL); Chlorpyrifos; Chlorpyrifos plus gamma-cyhalothrin (Cobalt); Chlorpyrifos plus zetacypermethrin (Stallion); Deltamethrin (Delta Gold); Gamma-cyhalothrin (Proaxis); Lambdacyhalothrin, Parathion, methyl (Cheminova Methyl 4EC) are appropriate for controlling

**Identification:** They are known as striate false wireworm, Eastern false wireworm and Southern false wireworm, respectively. Adult beetles of *Pterohelaeus* spp. are 20 mm long and dark grey-black with a distinctive 'pie-dish' shape formed by flanges around the outline of the beetle. Adults of *Gonocephalum* spp. are 9 mm long, dark grey-black and often covered in soil. There are flanges around the outline of the thorax (behind the head). Larvae are up to 30 mm long, shiny and cream, yellow or tan with three pairs of legs behind the head. They are hard-bodied, cylindrical and segmented with a rounded head (Murray, 2010).

**Life cycle and damage**: females lay eggs singly in moist soil, usually under trash or lowgrowing weeds. Both adults and larvae attack sunflower and damage of them may necessitate replanting. The larvae feed on decaying vegetable and crop residues in the soil; they also feed on newly germinating seed and the growing points of seedlings which results in patchy stands. Damage is most common in early-planted crops where crop residue has become scarce. They are major pests of seedling field crops and especially attack sunflower,

**Monitoring:** monitoring can be difficult; either hand sift 10 soil samples (30 x 30 cm) or place 10 germinating seed baits monitoring for soil-dwelling insects throughout the paddock. Pitfall traps can be used for counting the number of false wireworms (Brien, 2011). **Economic and action thresholds:** The action threshold is observing more than 25 wireworm

**Control**: Use of press wheels at planting; clean cultivation during summer can be effective against wireworms. Control of adults is obtained by baiting with insecticide-treated cracked and larvae can be controlled by insecticide applications at planting or insecticide-treated

soybeans, and mungbeans. They usually have one generation per year (Brien, 2011).

larvae in 20 germinating seed baits (Murray, 2010).

seed (Brien, 2011).

**6.7** *Pterohelaeus alternatus* **(Pascoe),** *Pterohelaeus darlingensis* **(Carter) and** 

*Gonocephalum macleayi* **(Blackburn) (Coleoptera: Tenebrionidae)** 

emergence continues over several weeks (Michaud et al., 2011).

seed weevils (Michaud et al., 2011).

#### **6.8** *Strauzia longipennis* **(Wiedemann) (Diptera: Tephritidae)**

**Identification:** Sunflower maggot is the only tephritid species found in the stalks of cultivated sunflowers. The showy yellow adult has a wing span of about 13 mm and a body length of 6 mm. The eyes are bright green and the wings bear broad dark bands that form a fairly distinct F pattern near the wing tip. Eggs are 1 mm long and are white and elongated. Larvae are yellow-white, headless and legless, tapered from anterior to posterior and approximately (7 mm) long at maturity (Knodel et al., n.d.).

**Life cycle and damage**: Adults emerge and flies have been noted in shelterbelts and field margins. Females lay eggs singly in stem tissue near the apical meristem, and larvae feed in the stalk pith, creating large tunnels. The maggots, when fully developed, emerge from the stalk. Larvae develop through three instars in approximately six weeks. This species overwinters as a larva in plant debris in the soil. The sunflower maggot has one generation per year. Feeding is confined to the pith, which acts as a supporting structure, and is not critical to plant nutrition. Secondary fungal infections also are associated with tunneling by the larvae within the stalk. Stalks are not weakened and seed yield is not reduced, even with severe pith destruction (Knodel et al., n.d.).

**Monitoring:** no scouting methods have been established for sunflower maggot.

**Economic and action thresholds:** no thresholds has been established for sunflower maggot.

**Control**: controlling other pests of sunflower will manage maggot infestations.

#### **6.9** *Trichoplusia ni* **(Hübner)***, Thysanoplusia orichalcea* **(F.) (Lepidoptera: Noctuidae)**

**Identification:** *T. ni* is known as cabbage loopers. Moths are dark, smoky, and gray variegated with light grayish brown. Characteristic small silvery oval spots and U-shaped silvery white marks are on the middle of the forewings. Hind wings are pale brown with the veins conspicuously visible. Males have tufts of gold hair at the tip of the abdomen. Eggs are hemispherical, pale green or white with shallow ridges that meet at the center of the egg. The newly emerged caterpillars are translucent white. Once feeding starts the larvae become pale green, with a thin white line running lengthwise down each side of the body and two white lines along the middle of the back. Pupae are yellow green with a few brown patches when newly formed and gradually darken to dark brown before adult emergence. The pupation occurs in white transparent silken cocoon in folded leaf (Mau et al., 2007). *T. orichalcea* is known as soybean looper, but larvae are an occasional pest of sunflower. The moth forewings are brown with a large, bright gold patch. Hind wings are fawn-colored, darkening towards the outer margins. The Eggs are pale yellow-green, ribbed and flat. Very small larvae are green all over but medium larvae usually have prominent dark and white striping. Larvae pupate under leaves in a thin silken cocoon. Pupae are dark above and pale underneath (Brier, 2010).

**Life cycle and damage**: females of *T. ni* lay eggs singly on the lower leaf surface near the leaf margin. Eggs hatch in 3-4 days. This is one of the major pests of sunflower. The young larvae feed on chlorophyll contents and make part of leaf transparent. As the larvae grown they feed on the leaf margins and during severe infestation only midribs are left. The presence of small transparent leaf spot, devoid of chlorophyll symbolizes the beginning of pest population. The caterpillar stage lasts for 12-20 days. The pupal stage lasts for 9 days

Oilseed Pests 171

body. There are initially gregarious, but disperse once their initial food plant is consumed

**Life cycle and damage**: Females lay their eggs in large clusters, often as many as 100. Even large plants can be completely skeletonized by larval feeding, but more damage can occur when egg clusters are laid on young plants in the V4-V6 stage, in which case the entire plant is quickly consumed and larvae migrate to neighboring plants, sometimes creating a bare

**Economic and action thresholds:** The action threshold for defoliation of established plants is 25%, but treatment can only be justified if larvae are still less than 3 cm long, as larger

**6.12** *Euxoa messoria* **(Harris),** *Euxoa ochrogaster* **(Guenee),** *Feltia jaculifera* **(Walker)** 

**Identification:** They are known as darksided cutworm, redbacked cutworm and dingy cutworm, respectively. The adult of darksided cutworm has light and grayish brown forewings with indistinct markings. Larvae are pale brown dorsally and white on the ventral areas. The sides have numerous indistinct stripes. At maturity, they are about 32 to 38 mm long and 6 mm wide. Redbacked cutworm moth has reddish brown forewings with characteristic bean-shaped markings. Larvae are dull gray to brown and are about 25 to 32 mm long when mature. Larvae can be distinguished from other cutworm species by two dull reddish stripes along the back. Dingy cutworm forewings are dark brown with beanshaped markings as in redbacked cutworm adults. Hind wings of the male are whitish with a broad, dark border on the outer margin; in the female, they are uniform dark gray. Larvae are dull, dingy brown body mottled with cream color and have a thin light line down the middle of the back with a series of diagonal markings on either side (Knodel et al., n.d.).

**Life cycle and damage**: Females of darksided and redbacked cutworm moths lay their eggs in the soil. The larvae continue to feed and grow until when mature; mature larvae pupate in earthen cells near the soil surface. The pupal period lasts about three weeks. Both species have one generation per year. Adult dingy cutworms lay eggs on plants in the family Asteraceae in the fall. Larvae develop to the second or third instar in the fall and overwinter in the soil. It has one generation per year. Due to the larval feedings seedlings being cut off from 25 mm below the soil surface to as much as 25-50 mm above the soil surface. Young leaves may be severely chewed from cutworms (notably the darksided cutworm) climbing up to feed on the plant foliage. During the daytime, cutworms usually are found just beneath the soil surface near the base of recently damaged plants and feed at night. Wilted or dead plants indicate the presence of cutworms. Cut plants may dry and blow away, leaving bare patches in the field as evidence of cutworm infestations (Knodel et al., n.d.).

**Monitoring:** monitoring should be done as soon as sunflower plants emerge, and fields should be checked at least twice per week. A trowel or similar tool should be used to dig around damaged plants to determine if cutworms are present. The Z pattern should be used to determine cutworm population levels by examining five 1-square-foot (30 by 30 cm) soil

samples per site (in the row) for a total of 25 samples (Knodel et al., n.d.).

hole in the field. They have typically two generations per year (Michaud et al., 2011).

**Control**: Use materials registered for painted lady caterpillars on sunflower.

**Monitoring:** refer to the *V. cardui* monitoring in sunflower*.*

larvae will soon cease feeding (Michaud et al., 2011).

(Michaud et al., 2011).

**(Lepidoptera: Noctuidae)** 

(Mau et al., 2007). *T. orichalcea* small larvae feed on only one side of the leaf. Developed larvae chew holes in the leaf, and then feed from the leaf margin. Larvae are primarily foliage feeders in soybeans but will attack the flowers and developing pods (Brier, 2010).

**Monitoring:** Beat-sheet is preferred sampling method for loopers. Also, light and pheromone traps can be used for monitoring and determining the moths peak (Brier, 2010).

**Economic and action thresholds:** An action threshold for *T. ni* is observing 0.5 cabbage looper per plant. In the case of *T. orichalcea* in pre-flowering crops, looper control is warranted if defoliation exceeds 33%. Tolerable defoliation drops to 15-20% once flowering and podding commences (Brier, 2010; Maxwell & Fadamiro, 2006).

**Control:** loopers can be controlled biologically by releasing *Copidosoma floridanum* (Ashmead)*, Voria ruralis* (Fallen), *Hyposoter exiguae* (Viereck), *Enicospilus* sp. and *Disophrys lutea* (Brulle). Also, conservation bio-control agents like green muscardine fungus, NPV, B.t. may be effective for reducing population build up. If the threshold is exceeded applying insecticides such as quinalphos 25 EC and Endosulfan 4% is recommended (TIFP, n.d.-c).

#### **6.10** *Vanessa cardui* **(L.) (Lepidoptera: Nymphalidae)**

**Identification:** The painted lady adult has a pointed forewing with a distinctive transverse white bar. The intensity of reddish coloration on the wings varies greatly, with some individuals brightly colored and others appearing quite drab. The eggs are green and barrelshaped. The larvae are spiny, covered with bristles, and range in background coloration from mottled, pale green to dark, purplish hues (Michaud et al., 2011).

**Life cycle and damage**: During summer, loosely-knit swarms migrate northward in search of suitable food plants. When large numbers of adults arrive in sunflower fields there is the potential for substantial defoliation to occur. Females lay eggs singly on the upper surfaces of leaves and the eggs hatch after 3-5 days. The larvae feed singly, skeletonizing leaves and tying up silken nests that typically accumulate piles of larval frass. So, damage is normally confined to individual plants, but when many plants are affected, an effort to estimate percent defoliation in the field may be justified. The caterpillar takes 7-11 days to turn into a chrysalis and 7–11 days for the chrysalis to turn into a butterfly (Michaud et al., 2011).

**Monitoring:** monitor by walking and examining 20 plants at each of five separate locations and determine percentage of defoliation in each location (Michaud et al., 2011).

**Economic and action thresholds:** action threshold is when plants have sustained 25% defoliation and larvae are still less than 3 cm long (Michaud et al., 2011).

**Control**: Applying insecticides is advised if the threshold is exceeded. Chlorpyrifos plus gamma-cyhalothrin (Cobalt); Chlorpyrifos plus zeta-cypermethrin (Stallion); Gammacyhalothrin (Proaxis) and Lambda-cyhalothrin are recommended (Michaud et al., 2011).

#### **6.11** *Chlosyne (Charidryas) nycteis* **(Doubleday) (Lepidoptera: Nymphalidae)**

**Identification:** Silvery Checkerspot is similar in appearance and biology to the painted lady, just the silvery checkerspot has more yellow and less red coloration on the wings. The lower surface of the hind wing bears a large, white crescent on its margin. The larvae are dark and covered with branching bristles with a distinctive yellow line running down each side of the

(Mau et al., 2007). *T. orichalcea* small larvae feed on only one side of the leaf. Developed larvae chew holes in the leaf, and then feed from the leaf margin. Larvae are primarily foliage feeders in soybeans but will attack the flowers and developing pods (Brier, 2010).

**Monitoring:** Beat-sheet is preferred sampling method for loopers. Also, light and pheromone traps can be used for monitoring and determining the moths peak (Brier, 2010). **Economic and action thresholds:** An action threshold for *T. ni* is observing 0.5 cabbage looper per plant. In the case of *T. orichalcea* in pre-flowering crops, looper control is warranted if defoliation exceeds 33%. Tolerable defoliation drops to 15-20% once flowering

**Control:** loopers can be controlled biologically by releasing *Copidosoma floridanum* (Ashmead)*, Voria ruralis* (Fallen), *Hyposoter exiguae* (Viereck), *Enicospilus* sp. and *Disophrys lutea* (Brulle). Also, conservation bio-control agents like green muscardine fungus, NPV, B.t. may be effective for reducing population build up. If the threshold is exceeded applying insecticides such as quinalphos 25 EC and Endosulfan 4% is recommended (TIFP, n.d.-c).

**Identification:** The painted lady adult has a pointed forewing with a distinctive transverse white bar. The intensity of reddish coloration on the wings varies greatly, with some individuals brightly colored and others appearing quite drab. The eggs are green and barrelshaped. The larvae are spiny, covered with bristles, and range in background coloration

**Life cycle and damage**: During summer, loosely-knit swarms migrate northward in search of suitable food plants. When large numbers of adults arrive in sunflower fields there is the potential for substantial defoliation to occur. Females lay eggs singly on the upper surfaces of leaves and the eggs hatch after 3-5 days. The larvae feed singly, skeletonizing leaves and tying up silken nests that typically accumulate piles of larval frass. So, damage is normally confined to individual plants, but when many plants are affected, an effort to estimate percent defoliation in the field may be justified. The caterpillar takes 7-11 days to turn into a chrysalis and 7–11 days for the chrysalis to turn into a butterfly (Michaud et al., 2011).

**Monitoring:** monitor by walking and examining 20 plants at each of five separate locations

**Economic and action thresholds:** action threshold is when plants have sustained 25%

**Control**: Applying insecticides is advised if the threshold is exceeded. Chlorpyrifos plus gamma-cyhalothrin (Cobalt); Chlorpyrifos plus zeta-cypermethrin (Stallion); Gammacyhalothrin (Proaxis) and Lambda-cyhalothrin are recommended (Michaud et al., 2011).

**Identification:** Silvery Checkerspot is similar in appearance and biology to the painted lady, just the silvery checkerspot has more yellow and less red coloration on the wings. The lower surface of the hind wing bears a large, white crescent on its margin. The larvae are dark and covered with branching bristles with a distinctive yellow line running down each side of the

and determine percentage of defoliation in each location (Michaud et al., 2011).

**6.11** *Chlosyne (Charidryas) nycteis* **(Doubleday) (Lepidoptera: Nymphalidae)** 

defoliation and larvae are still less than 3 cm long (Michaud et al., 2011).

and podding commences (Brier, 2010; Maxwell & Fadamiro, 2006).

from mottled, pale green to dark, purplish hues (Michaud et al., 2011).

**6.10** *Vanessa cardui* **(L.) (Lepidoptera: Nymphalidae)** 

body. There are initially gregarious, but disperse once their initial food plant is consumed (Michaud et al., 2011).

**Life cycle and damage**: Females lay their eggs in large clusters, often as many as 100. Even large plants can be completely skeletonized by larval feeding, but more damage can occur when egg clusters are laid on young plants in the V4-V6 stage, in which case the entire plant is quickly consumed and larvae migrate to neighboring plants, sometimes creating a bare hole in the field. They have typically two generations per year (Michaud et al., 2011).

**Monitoring:** refer to the *V. cardui* monitoring in sunflower*.*

**Economic and action thresholds:** The action threshold for defoliation of established plants is 25%, but treatment can only be justified if larvae are still less than 3 cm long, as larger larvae will soon cease feeding (Michaud et al., 2011).

**Control**: Use materials registered for painted lady caterpillars on sunflower.

#### **6.12** *Euxoa messoria* **(Harris),** *Euxoa ochrogaster* **(Guenee),** *Feltia jaculifera* **(Walker) (Lepidoptera: Noctuidae)**

**Identification:** They are known as darksided cutworm, redbacked cutworm and dingy cutworm, respectively. The adult of darksided cutworm has light and grayish brown forewings with indistinct markings. Larvae are pale brown dorsally and white on the ventral areas. The sides have numerous indistinct stripes. At maturity, they are about 32 to 38 mm long and 6 mm wide. Redbacked cutworm moth has reddish brown forewings with characteristic bean-shaped markings. Larvae are dull gray to brown and are about 25 to 32 mm long when mature. Larvae can be distinguished from other cutworm species by two dull reddish stripes along the back. Dingy cutworm forewings are dark brown with beanshaped markings as in redbacked cutworm adults. Hind wings of the male are whitish with a broad, dark border on the outer margin; in the female, they are uniform dark gray. Larvae are dull, dingy brown body mottled with cream color and have a thin light line down the middle of the back with a series of diagonal markings on either side (Knodel et al., n.d.).

**Life cycle and damage**: Females of darksided and redbacked cutworm moths lay their eggs in the soil. The larvae continue to feed and grow until when mature; mature larvae pupate in earthen cells near the soil surface. The pupal period lasts about three weeks. Both species have one generation per year. Adult dingy cutworms lay eggs on plants in the family Asteraceae in the fall. Larvae develop to the second or third instar in the fall and overwinter in the soil. It has one generation per year. Due to the larval feedings seedlings being cut off from 25 mm below the soil surface to as much as 25-50 mm above the soil surface. Young leaves may be severely chewed from cutworms (notably the darksided cutworm) climbing up to feed on the plant foliage. During the daytime, cutworms usually are found just beneath the soil surface near the base of recently damaged plants and feed at night. Wilted or dead plants indicate the presence of cutworms. Cut plants may dry and blow away, leaving bare patches in the field as evidence of cutworm infestations (Knodel et al., n.d.).

**Monitoring:** monitoring should be done as soon as sunflower plants emerge, and fields should be checked at least twice per week. A trowel or similar tool should be used to dig around damaged plants to determine if cutworms are present. The Z pattern should be used to determine cutworm population levels by examining five 1-square-foot (30 by 30 cm) soil samples per site (in the row) for a total of 25 samples (Knodel et al., n.d.).

Oilseed Pests 173

Defoliation of 20 to 30% was associated with significant increases in total dry matter, seed yield, and number of capitula. Further defoliation resulted in decreases of dry weight, seed

**Economic and action thresholds:** action threshold is when 8 or more grasshoppers per

**Identification:** the synonym of safflower aphids is *Uroleucon compositae* (Theobald). Adults are about 1.5-2 mm long, black with pear-shaped body and conspicuous cornicles. Nymphs

**Life cycle and damage:** It is a serious pest of safflower. During pre-flowering stage both nymphs and adults suck the cell sap from shoot apices, peduncles, leaves and stem, secrete a honey dew like secretion on upper surface of the leaves and plant parts forming a black sooty mold which hinders photosynthetic activity resulting in stunted growth. In sever attacks the plants dry up. Yield losses cause by aphids is about 40-50% and infestation may occur 30-45 days old crop. It has four nymphal stages (TNAU, n.d.-a). There are other major aphids species that cause severe or moderate damage to safflower such as *Uroleucon compositae* (Theobold), *Dactynotus orientali*s sp., *Dactyonotus jaceae* (Linn.), *Macrosiphum sonchi*  (H.R.L.), *Macrosiphum sonchi* (Linn.), *Macrosiphum compositae* (Theobold), *Macrosiphum*  spp.(jaceae), *M. persicae*, *Aphis fafia* (Scop) and *Capitophorus eleagni* (Del Guercio)

**Economic and action thresholds:** The economic threshold level is observing 50-60 aphids/5cm twig/plant (Martínez, 1999). However, the economic threshold level differs according to the variety. For *U. compositae* ETL was determined 48.78 aphids/5 cm apical twig/plant on Bhima variety of safflower, with exposure periods of about 2-3 weeks from first aphid incidence. On Annigeri-1 variety of safflower, the ETL was estimated at 38.5 aphids/5 cm apical twig/plant with exposure periods of 2-3 weeks from first aphid

**Control:** planting resistant varieties and early sowing escape the peak pest incidence. Application of balanced fertilizer, intercropping and mixed cropping reduces the pest population. Intercultural operations like harrowing; hoeing can reduces the weeds which are host plants for safflower aphids. Also, releasing natural enemies can be used in

**Identification:** Capsule fly or safflower bud fly adults are ash colored; black obscured by a dense gray microtrichia and wing with characteristic diffused pattern. They have light

**7.2** *Dactynotus carthami* **(Hille Ris Lambers) [basionym] (Homoptera: Aphididae)** 

yield, and capitula number (Mundel & Johnson, 1987).

square yard occur in the field (Knodel et al., 2010).

are reddish brown (Martínez, 1999).

(Hanumantharaya et al., 2008).

**Monitoring:** install yellow traps for monitoring aphids.

augmentation programs (Hanumantharaya et al., 2008).

**7.3** *Acanthiophilus helianthi* **(Rossi) (Diptera: Tephritidae)** 

brown legs. Maggot is dirty white in color (Martínez, 1999).

appearance (Hanumantharaya et al., 2008).

**Monitoring:** refer to the monitoring section for grasshoppers in cotton.

**Control:** refer to the control section for grasshoppers in cotton.

**Economic and action thresholds:** The economic threshold is one larva per square foot (30 by 30 cm) or 25-30% stand reduction (Knodel et al., n.d.).

**Control**: Several insecticides are registered for cutworm control in sunflowers. Post emergent treatment with an insecticide provides quick control of surface feeding cutworms. Best results occur if insecticide applied at night. Seed treatment will provide suppression of cutworm activity (Knodel et al., n.d.).

#### **6.13** *Psittacula krameri krameri* **(Scopoli),** *Psittacula krameri manillensis* **(Bechstein) and** *Psittacula krameri borealis* **(Neumann)**

**Identification:** They are known as African ring-necked parakeet, Indian ring-necked parakeet and Neumann's ring-necked parakeet, respectively. *P. K. krameri* is green, face, abdomen and under wing-coverts yellowish-green; nape and back of head variably washed with blue; chin, broad cheek-stripe; narrow band to nape pink; upperside of middle tailfeathers blue with greenish-yellow tips, outer feathers green; underside of outer tail-feathers olive-yellowish, middle feathers blackish; bill blackish-red with black tips; iris yellowishwhite; feet greenish-grey. *P. K. manillensis* is much darker; face stronger green; blue tinge to nape extends in many birds to back of head; breast and abdomen feathers tinged bluishgrey; upper mandible red, lower mandible black; larger. However, *P. K. borealis* is as *krameri*, but face pale green; breast and abdomen feathers in both sexes with marked grey-white tinge; smaller upper mandible red with black tip (Rana, n.d.).

**Life cycle and damage**: They mostly observed in small groups. They clutch 2-6 eggs; which incubated in 21 to 24 days; and fledging period is about 6 to 7 weeks. The birds' damage starts from the milky stage and continues till harvest. They consume an average of 152 seeds per day. The damage of the birds was highest at the mature stage, 23.8%, and minimum, 7.60%, on the emerging stage of sunflower. Also, other birds such as sparrows, crows and blackbirds can damage sunflower crops (Ahmad et al., 2011; TNAU, n.d.-b)**.** 

**Control**: Establishment of scare crows in the field; bursting of crackers and carbide guns, tying polythene bags may decrease birds' infestations. Destruction of bird nest in and around the field and deploying two laborers per hectare to scare away the birds may be effective. Spraying of neem kernel powder solution at 10 g/liter of water after seed shedding for repelling the birds can be applied (TNAU, n.d.-b).
