**2.10** *Pectinophora gossypiella* **(Saunders) (Lepidoptera: Gelechiidae)**

**Identification:** The moth is small and dark brown with blackish bands on the forewings, and hind wings are silvery grey. Eggs are flattened oval and striate about 0.5 mm long, 0.25 mm wide. The larvae are pinkish with dark brown head and about 15 mm length. Pupae are in a thin silken cocoon among the lint inside a seed, in between bracts or in cracks in the soil.

**Life cycle and damage:** The pink bollworm female lays the eggs on the bolls or in between bracts or on buds and flowers. After 4-25 days, due to the weather conditions, eggs hatch and larvae crawl to the bolls. Larva full grown in 25-35 days and the pupal period is about 6-20 days. The larvae feed early in the season from the inside of the green bolls. Seeds being destroyed in addition to retardation of lint development, lint weakened and stained both inside the boll and in the gin, causing lint yield losses. In addition, infested bolls open prematurely and are invaded by saprophytic fungi.

**Monitoring:** monitoring can be done with pheromone baited traps as well as by sampling flowers and bolls to record damage levels in cotton fields (Lykouressisa et al., 2005).

**Economic and action thresholds**: the economic threshold is 8 moths per trap (glossyplure pheromone traps) per day for 3 consecutive days. The number of traps should be 5 per ha or 10% infested flowers or bolls with live larvae (Sabesh, 2004).

**Control:** Biological control of larvae with *Chelonus* sp., *Camptothlipsis* sp., and *C. blackburni*  (Cam.) is effective against overwintering stage. Parasitoids include *Trichogramma brasiliensis*  (Ashm.), *Bracon kirkpatricki* (Wilkinson), *Chelonus blackburni* (Cameron); predatory mites such as *Pyemotes ventricosus* (Newport) and *P. herfsi* (Oudemans) are widely reported on reducing bollworm population. Also, entomopathogenic nematodes (Rhabditida: Steinernematidae) such as S*teinernema riobravis* (Cabanillas, Poinar and Raulston) and *Steinernema carpocapsae* (Weiser) may control pests infestations. Applying insecticides is advised if the threshold is exceeded. Application of carbaryl 50 WP, quinalphos 25 EC, profenofos 50 EC, or fumigation of seeds with aluminum phosphide at 18 tablets per 100 cu. m. is recommended (Gouge et al., 1998; Navarajan, 2007; Salama, 1983; Vennila, n.d.).

#### **2.11** *Heliothis armigera* **(Hübner) and** *Heliothis punctigera* **(Wallengren) (Lepidoptera: Noctuidea)**

**Identification:** moth of *H. armigera* is about 35 mm long, with a small pale patch in the dark section of the hind wing; while in *H. punctigera* the dark section is uniform. Eggs of both species are 0.5 mm in diameter, sculptured with longitudinal ribs. *H. armigera* larvae have white hairs around head; medium larvae have saddle of dark pigment on 4th segment from head, and have dark legs. *H. punctigera* larvae have black hairs on the prothorax, dark triangles on the first abdominal segment with light legs. Pupa is smooth surfaced, brown, rounded both anterior and posterior with two tapering parallel spines at posterior tip (Vennila, n.d.).

**Life cycle and damage:** *H. punctigera* is known as native budworm; and *H. armigera* is the cotton bollworm or corn earworm. *H. armigera* occurs throughout the Africa, Western Europe and Australian pacific region. The adults lay their eggs on young terminal branches of the cotton and after 2 or 3 days the eggs hatch and larvae go through the young leaves and flower buds. So, they burrow fruit and feed from developing seeds and fibers until

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larval ultimate period. Bollworms have four or five generations and in the last generation burrow into the soil around the base of plant for overwintering and the pupae emerge from the soil in the next spring. *H. punctigera* is similar to *H. armigera*; just there are a few differences between them, such as *H. armigera* usually prefers grass or cereal crops but *H. punctigera* prefers to feed on broadleaf species (e.g. cotton, sunflower, soybean, canola, safflower, linseed and etc.). The diapause is not common in *H. punctigera* (Vennila, n.d.). *H. armigera* also severely damage other oilseeds such as sunflower.

**Monitoring:** monitore from seedling emergence to maturity of the cotton for the presence of eggs and larvae. Pheromone traps (5 per ha) will detect the presence and intensity of adults (Yvette & Jensen, 2009).

**Economic and action thresholds**: the economic threshold in early stages of the crop is 2-3 larvae with about 3 mm length/m or 1 larva > 8 mm and for the time when 15-40% of the bolls opened, 5 larvae with 3 mm length/m or 2 larva > 8 mm/m (Yvette & Jensen, 2009).

**Control:** mechanical cultivation of the soil at the end of the season destroys the tunnels and shelters made by the larvae and can kill over 90% of the pupae in the soil. *Trichogramma*  spp., *Compoletis chloridae* (Uchida) can release against early instar larvae and Tachinids: *Carcelia illota* (Curran), *Goniopthalmus halli* (Mesnil.) and *Paleorixa laxa* (Curran) have been recorded on late larval instars of *H. armigera* (Vennila, n.d.). Spraying insecticides can be applied by consulting the field guide because *H. armigera* indicates resistance to insecticides (Salama, 1983). Recently, planting of transgenic *Bacillus thuringiensis* (Bt) cotton seeds is approved (Menon & Jayaraman, 2002).

#### **2.12** *Earias insulana* **(Boisd.) and** *Earias vittella* **(F.) (Lepidoptera: Noctuidae)**

**Identification:** *E. vittella* moth has green forewings with a white streak on each of them whereas that of *E. insulana* is completely green. The eggs are less than 0.5 mm diameter, crown-shaped, sculptured and blue. The larva of *E. vittella* is brownish with a longitudinal white stripe on the dorsal side and without finger-shaped processes on its body. Larva is cream with orange dots on the prothroax. The boat shaped tough silken cocoon is dirty white brownish (Navarajan, 2007).

**Life cycle and damage:** They are known as spotted bollworm. Females lay eggs singly on most parts of the cotton such as flower buds, bolls, peduncles, bracts, leaf axils and veins on the under surface of leaf and after 3 days eggs hatch. The larval period is about 10-12 days. In the early vegetative stage of the crop the larvae cause damage to the terminal bud of the shoots and channel downwards or into inter node which redound to drying the shoot. Afterward, in the later stages of the crop growth; the larvae migrate to the buds, flowers, bolls and fresh parts of the plants and damaged them. Tunnel in bolls is often from below, angled to the peduncle. Larvae do not confine their feeding to a complete single boll; hence damage is disproportionate to their numbers. So, heavy shedding of early formed flower buds is observed in cotton fields and the lint from attacked bolls will not be clean. The period of pupae is 7-10 days. The total life cycle ranges from 20 to 22 days (Navarajan, 2007).

**Monitoring:** monitor the population fluctuation by installation synthetic sex pheromone traps. Also, determine larval infestation in bolls of cotton (Qureshi & Ahmed, 1991)

**Economic and action thresholds**: the economic threshold is differ from region to region, Navarajan (2007) stated 5% damaged fruiting bodies or one larva per plant from 20


larval ultimate period. Bollworms have four or five generations and in the last generation burrow into the soil around the base of plant for overwintering and the pupae emerge from the soil in the next spring. *H. punctigera* is similar to *H. armigera*; just there are a few differences between them, such as *H. armigera* usually prefers grass or cereal crops but *H. punctigera* prefers to feed on broadleaf species (e.g. cotton, sunflower, soybean, canola, safflower, linseed and etc.). The diapause is not common in *H. punctigera* (Vennila, n.d.). *H.* 

**Monitoring:** monitore from seedling emergence to maturity of the cotton for the presence of eggs and larvae. Pheromone traps (5 per ha) will detect the presence and intensity of adults

**Economic and action thresholds**: the economic threshold in early stages of the crop is 2-3 larvae with about 3 mm length/m or 1 larva > 8 mm and for the time when 15-40% of the bolls opened, 5 larvae with 3 mm length/m or 2 larva > 8 mm/m (Yvette & Jensen, 2009). **Control:** mechanical cultivation of the soil at the end of the season destroys the tunnels and shelters made by the larvae and can kill over 90% of the pupae in the soil. *Trichogramma*  spp., *Compoletis chloridae* (Uchida) can release against early instar larvae and Tachinids: *Carcelia illota* (Curran), *Goniopthalmus halli* (Mesnil.) and *Paleorixa laxa* (Curran) have been recorded on late larval instars of *H. armigera* (Vennila, n.d.). Spraying insecticides can be applied by consulting the field guide because *H. armigera* indicates resistance to insecticides (Salama, 1983). Recently, planting of transgenic *Bacillus thuringiensis* (Bt) cotton seeds is

**2.12** *Earias insulana* **(Boisd.) and** *Earias vittella* **(F.) (Lepidoptera: Noctuidae)** 

**Identification:** *E. vittella* moth has green forewings with a white streak on each of them whereas that of *E. insulana* is completely green. The eggs are less than 0.5 mm diameter, crown-shaped, sculptured and blue. The larva of *E. vittella* is brownish with a longitudinal white stripe on the dorsal side and without finger-shaped processes on its body. Larva is cream with orange dots on the prothroax. The boat shaped tough silken cocoon is dirty

**Life cycle and damage:** They are known as spotted bollworm. Females lay eggs singly on most parts of the cotton such as flower buds, bolls, peduncles, bracts, leaf axils and veins on the under surface of leaf and after 3 days eggs hatch. The larval period is about 10-12 days. In the early vegetative stage of the crop the larvae cause damage to the terminal bud of the shoots and channel downwards or into inter node which redound to drying the shoot. Afterward, in the later stages of the crop growth; the larvae migrate to the buds, flowers, bolls and fresh parts of the plants and damaged them. Tunnel in bolls is often from below, angled to the peduncle. Larvae do not confine their feeding to a complete single boll; hence damage is disproportionate to their numbers. So, heavy shedding of early formed flower buds is observed in cotton fields and the lint from attacked bolls will not be clean. The period of pupae is 7-10 days. The total life cycle ranges from 20 to 22 days (Navarajan, 2007). **Monitoring:** monitor the population fluctuation by installation synthetic sex pheromone

traps. Also, determine larval infestation in bolls of cotton (Qureshi & Ahmed, 1991)

**Economic and action thresholds**: the economic threshold is differ from region to region, Navarajan (2007) stated 5% damaged fruiting bodies or one larva per plant from 20

*armigera* also severely damage other oilseeds such as sunflower.

(Yvette & Jensen, 2009).

approved (Menon & Jayaraman, 2002).

white brownish (Navarajan, 2007).


Fig. 2. Some effective pesticides against cotton pests and their efficiency on parasitoids, predators and bees (Yvette & Jensen, 2009).

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randomly counted plants. However in the other study, Qureshi & Ahmed (1991) declared that a mean trap catches of 9-12 moths per night was associated with economic injury level

**Control**: application of insecticides such as phosalone 35 EC, carbaryl 50 WP, endosulfan 35 EC, monocrotophos 40 SC, thiodicarb 75 WP, or profenofos 50 EC are advised. Also, the synthetic pyrethroids, fenvalerate, deltamethrin and permethrin has been reported to be

*Arachis villosulicarpa* Hoehne: known as groundnut; cultivated in some states of Brazil. *Vigna subterranea* L.: known as Bambara groundnut; originated in West Africa and a

*Macrotyloma geocarpum* Harms: known as geocarpa groundnut, Hausa groundnut, or

*Arachis hypogaea* L.: known as peanut, earthnuts, ground nuts, goober peas, monkey nuts, pygmy nuts and pig nuts. About 41.5% of world production is in China, 18.2% in India and

Also, roots and: *Apios americana* Medik.: known as potato bean, hopniss, Indian potato or

*Conopodium majus* Gouan: known as kippernut, cipernut, arnut, jarnut, hawknut, earth

**Identification:** females are reddish, and more or less elliptical. The males are slightly smaller and wedge shaped. They have a black spot on either side of their relatively colorless bodies. Eggs are spherical, shiny, straw colored. Larvae are slightly larger than the egg, pinkish, and have three pairs of legs. They have two nymphal stages, the protonymph and deutonymph. The nymphal stage differs from the larval stage by being slightly larger,

**Life cycle and damage:** the females lay eggs singly on the underside of the leaf or attached to the silken webs spun which hatch in 3 days. The larval stage lasts a short time, perhaps a day and afterward formed the nymphs. Nymphal stage lasts about 4 days. Spider mites feed on the underside of the uppermost leaves. They can be very serious pests during extended dry periods (Mau & Kessing, 2007a). Resistance of peanut, and wild species of *Arachis* has

**Monitoring:** monitor for areas of light colored (chlorotic) plants, especially along field

**Control:** mites quickly resist to pesticide so consult with county Cooperative Service

**Economic and action thresholds:** No threshold has been set for mites (Linker et al., n.d.).

A few of the insect pests that cause economic losses to groundnut are introduced here:

chestnut, groundnut, and earthnut, native to Europe and parts of North Africa. *Panax* spp*.:* is in parts of north America and eastern Asia (Wikipedia, 2010).

**3.1** *Tetranychus cinnabarinus* **(Bois.) (Acari: Tetranychidae)** 

reddish or greenish, and having 4 pairs of legs (Mau & Kessing, 2007a).

been declared to the two spotted spider mite in the USA (Lynch, 1990).

Extension agent which pesticides are associated with mite problems.

edges. Look under the top leaves to see if mites are present (Linker et al., n.d.).

and the economic threshold is 10% larval damage.

effective against bollworms (Navarajan, 2007).

Kersting's groundnut, in Sub-Saharan Africa.

groundnut, native to eastern North America.

6.8% in the United States of America.

**3. Groundnuts** 

Groundnuts contain seeds of:

traditional food plant in Africa.

Fig. 2. Some effective pesticides against cotton pests and their efficiency on parasitoids,

predators and bees (Yvette & Jensen, 2009).

randomly counted plants. However in the other study, Qureshi & Ahmed (1991) declared that a mean trap catches of 9-12 moths per night was associated with economic injury level and the economic threshold is 10% larval damage.

**Control**: application of insecticides such as phosalone 35 EC, carbaryl 50 WP, endosulfan 35 EC, monocrotophos 40 SC, thiodicarb 75 WP, or profenofos 50 EC are advised. Also, the synthetic pyrethroids, fenvalerate, deltamethrin and permethrin has been reported to be effective against bollworms (Navarajan, 2007).
