**3.8** *Diabrotica undecimpunctata howardi* **(Barber) (Coleoptera: Chrysomelidae)**

**Identification:** adults are greenish-yellow beetles and have 12 irregular black spots on their backs. Eggs are about 0.5 mm long, oval and yellow. The damage to peanuts, however, is caused by the whitish-clear tender looking larvae. The larvae are 12-19 mm long and have a dark head, and a small dark spot at the rear (Mossler & Aerts, 2009).

**Life cycle and damage**: The southern corn rootworm female lays 200-1200 eggs in the soil near host plants. They usually hatch in 1-2 weeks, depending on the temperature. Larvae damage peanuts by feeding on the pods and pegs in the soil. These pests tend to be a problem more often in damp weather and on heavier type soils; however, it can occur in sandy soils. Larvae develop over about 2-4 weeks. They then pupate in the soil and adults emerge about 1-2 weeks later. Adults may also be vectors of plant pathogenic bacteria and viruses, e.g. *Pantoea stewartii* subsp. *stewartii* (synonym: *Erwinia stewartii*) (Linker et al., n.d.).

**Monitoring:** monitor after pegging with a hand trowel or small spade to unearth the nuts under 2-3 row feet of plants (without digging up the plants). Monitor randomly, but check low, moist spots or areas of heavier soil where plants are most likely to show signs of damage. Examine the pegs and pods for small holes and signs of boring (Linker et al., n.d.).

**Economic and action thresholds:** no threshold has been set for rootworm. However, if 10% of samples showed live larvae or fresh damage, treatment is advised (Linker et al., n.d.).

**Control:** management of this pest can be quite frustrating because it feeds underground. Early-planted fields or crop rotated ones are at less risk from damage. Apply insecticides such as Chlorpyrifos if the threshold is exceeded (Mossler & Aerts, 2009).

#### **3.9** *Stomopteryx submissella* **(Frey) and** *Aproaerema modicella* **(Deventer) (Lepidoptera: Gelechiidae)**

**Identification:** The moth of *S. submissella* is brownish gray, 6 mm long with 10 mm wing span. The eggs are shiny white. The larvae are about 1 mm long at first and enlarge as the larvae grow. Pupation takes place in the webbing (Jasani, 2009). *A. modicella* moths are brownish grey, 6 mm long with 10 mm wing span. Forewings have white spot on the costal margin. The larvae are green in color with dark head and prothroax (TNAU, n.d.-c).

**Life cycle and damage**: leaf miner is one of the most important pests of groundnut. The females lay eggs singly underside of the leaflets. Young larvae initially mine into the leaflets, feed on the mesophyll and form small brown blotches on the leaf. Afterward larvae web the leaflets together and feed on them, remaining within the folds (Jasani, 2009). In the USA plant resistance has been confirmed to the *A. modicella* (Lynch, 1990).

Oilseed Pests 137

**Identification:** the moths emerge from the soil at the onset of the south-west monsoon. They are brownish-white moths with a 40-50 mm wing span. The larvae are light brown and turn

**Life cycle and damage**: Females lay around 800-1000 eggs in clusters of 50-100 on the host plants. The eggs hatch in 2-3 days and tiny first instar caterpillars remain under the cover of natural vegetation for about 8-10 days. A week to 10 days old caterpillars spreads to the fields and start feeding. Red hairy caterpillars cause defoliation of the crop as they are voracious feeders and often migrate from one field to another devastating whatever crops come their way. After about 30-40 days of feeding the larvae burrow into soil, usually in the undisturbed soil of field or non-cropped areas and pupate for diapauses. They have one

**Monitoring:** monitor by erection of 12 light traps per ha for 20-45 days (Jasani, 2009).

Quinalphos 25 EC, Nuvan (76%) can control full grown insect pests (TNAU, n.d.-c).

reddish brown and are found in the soil close to the plant (Jasani, 2009).

**Identification:** Tobacco bud worm moths are light brown with a wing span of about 30 mm and mottled forewings. The eggs are laid in the masses about 4 × 7 mm and appear golden brown on the upper surface of leaves. Young larvae are light green in color. Full grown larvae are stout, cylindrical and pale greenish brown with dark markings. The pupae are

**Life cycle and damage**: females lay around 2000 eggs on the abaxial surface of groundnut leaves, in batches of 200-300 each. The larval and pupal periods take about 20 and 7-10 days, respectively. Freshly hatched larvae feed gregariously, scraping the chlorophyll, and they disperse very soon. Larvae feed mostly during night time. Later stages feed voraciously on the foliage at night, hiding usually in the soil around the base of the plants during the day. Sometimes the feeding is so heavy that only petioles and branches are left behind. In light soil, caterpillar bores into the pods. The total life cycle is completed in 30 days and there may be as many as 12 generations annually in southern India (Jasani, 2009; Mallikarjuna et al., 2004). Peanut and its wild species have three flavonoids chlorogenic acid, quercetin and

**Economic and action thresholds:** Economic threshold is when 15-20% of plants are affected. **Control**: there are different methods for managing this pest. The cultural techniques are: deep ploughing in summer to expose the pupae to predatory birds; early sowing to escape crop from pest infestations; mechanical weeding at 15-20 days after sowing; and intercropping one row of castor for every 5 or 6 rows of groundnut. Crop rotation with sorghum, pearl millet or maize should be followed. Vegetative traps utilizing jatropa (wild castor) or ipomoea prevent the migration of the grown up larvae. Irrigate once to avoid prolonged mid season drought to prevent pre-harvest infestation. Install light traps in endemic areas, collect then kill the moths. Collect and destruct egg masses in the fields around light trap areas. Red hairy caterpillar can be controlled biologically by releasing *Coccinella* sp., and parasitoids like *Bracon hebetor* (Say)*, Chelonus* spp. Also, spraying A-NPV and B.t can reduce the *A. albistriga* population and if the threshold is exceeded applying insecticides is recommended. Methyl parathion 2%, Fanvalerate 0.4%, Endosulfan 35 EC,

reddish as they grow. They are haired and are up to 5 cm long (Jasani, 2009).

**3.11** *Amsacta albistriga* **(Walker) (Lepidoptera: Arctiidae)** 

generation in a year (Jasani, 2009; TNAU, n.d.-c).

**3.12** *Spodoptera litura* **(F.) (Lepidoptera: Noctuidae)** 

**Monitoring:** monitor moths by pheromone trap, 1/ha or light trap 12/ha. Also, count the number of larvae on randomly selected plants in the field (Jasani, 2009).

**Economic and action thresholds:** Economic threshold is 2-3 larvae per plant or 10% leaflets damaged in central whorl (Bhubaneswar, 2008; Jasani, 2009).

**Control**: planting of cowpea or soybean as trap crop; crop rotation with non leguminous crop is advised and rotation with leguminous crops should be avoided. There are some resistant or tolerant varieties that can be planted. Egg masses and early instars larvae can be collected and destroyed manually. Also, installation of pheromone traps for mass trapping is one of the mechanical control techniques of leaf minor. *Trichogramma Chilonis* (Ishii) is special biological control agent of the minor in groundnut. *Pennisetum glacum* (L.) enhanced the parasitoid *Goniozus* spp. on leaf miner. Applying insecticides is recommended if the insect population crosses the ETL. Carbaryl 50WP, Quinalphos 25 EC, Methyldemeton 25 EC or Dimethoate 30 EC are effective against leaf minor (Jasani, 2009; TNAU, n.d.-c).

#### **3.10** *Spilosoma* **(***Diacrisia***)** *obliqua* **(Walker) (Lepidoptera: Arctiidae)**

**Identification:** Bihar hairy caterpillar moth is brown with a 40-50 mm wing span and a red abdomen. Eggs are light green spherical in clusters on the underside of leaves. The larvae are covered with long yellowish to black hairs and are up to 5 cm long. The pupa forms a thin silken cocoon by interwoven shed hairs of the larvae (Jasani, 2009; TNAU, n.d.-c).

**Life cycle and damage**: each female lays 533-1287 eggs and the eggs hatch after about 6-9 days. Larval and pupal stages lasted 34-45 and 16-22 days, respectively, giving a total life cycle of 59-76 days. Young larvae feed gregariously on the under surface of the leaves and cause loss by way of defoliation. Sometimes, after defoliated the crop larvae feed on the capsules. In severe cases only stems are left behind. Pupation takes place in the soil under dry foliage and debris where the pupae overwintering (Jasani, 2009; TNAU, n.d.-c). They also severely damage other oilseeds such as sunflower.

**Monitoring:** monitor the flight intensity of the male moth by using pheromone traps 5/ha and determine the percentage of crop defoliation (TNAU, n.d.-c).

**Economic and action thresholds:** economic threshold is when 20-25% defoliation is observed (Bhubaneswar, 2008).

**Control**: deep ploughing in the pre-monsoon (two/three times) will expose the hibernating pupae to sunlight and predatory birds. Removal and destruction of alternate wild hosts which is the harbor of caterpillars can be effective method of controlling *S. obliqua*. Also, planting trap crops like cowpea, castor and Jatropha on field bunds to attract the caterpillars may be efficient. Setting up bonfires on field bunds during night, mass collection and destruction of eggs and emerged larvae are mechanical ways of controlling hairy caterpillars. Spraying B.t is also advocated at 1 kg/ha where mulberry is not grown. Application of insecticides should be considered if the threshold is exceeded. Dust Lindan 1.3% and Fanvalerate 0.4% can use in the early stage of larvae. In addition, spraying Quinalphos 25 EC, Chlorpyriphos 20 EC or Endosulfan 35 EC recommended when the caterpillars are younger (Jasani, 2009; TNAU, n.d.-c).

**Monitoring:** monitor moths by pheromone trap, 1/ha or light trap 12/ha. Also, count the

**Economic and action thresholds:** Economic threshold is 2-3 larvae per plant or 10% leaflets

**Control**: planting of cowpea or soybean as trap crop; crop rotation with non leguminous crop is advised and rotation with leguminous crops should be avoided. There are some resistant or tolerant varieties that can be planted. Egg masses and early instars larvae can be collected and destroyed manually. Also, installation of pheromone traps for mass trapping is one of the mechanical control techniques of leaf minor. *Trichogramma Chilonis* (Ishii) is special biological control agent of the minor in groundnut. *Pennisetum glacum* (L.) enhanced the parasitoid *Goniozus* spp. on leaf miner. Applying insecticides is recommended if the insect population crosses the ETL. Carbaryl 50WP, Quinalphos 25 EC, Methyldemeton 25

EC or Dimethoate 30 EC are effective against leaf minor (Jasani, 2009; TNAU, n.d.-c).

**Identification:** Bihar hairy caterpillar moth is brown with a 40-50 mm wing span and a red abdomen. Eggs are light green spherical in clusters on the underside of leaves. The larvae are covered with long yellowish to black hairs and are up to 5 cm long. The pupa forms a thin silken cocoon by interwoven shed hairs of the larvae (Jasani, 2009; TNAU, n.d.-c).

**Life cycle and damage**: each female lays 533-1287 eggs and the eggs hatch after about 6-9 days. Larval and pupal stages lasted 34-45 and 16-22 days, respectively, giving a total life cycle of 59-76 days. Young larvae feed gregariously on the under surface of the leaves and cause loss by way of defoliation. Sometimes, after defoliated the crop larvae feed on the capsules. In severe cases only stems are left behind. Pupation takes place in the soil under dry foliage and debris where the pupae overwintering (Jasani, 2009; TNAU, n.d.-c). They

**Monitoring:** monitor the flight intensity of the male moth by using pheromone traps 5/ha

**Economic and action thresholds:** economic threshold is when 20-25% defoliation is

**Control**: deep ploughing in the pre-monsoon (two/three times) will expose the hibernating pupae to sunlight and predatory birds. Removal and destruction of alternate wild hosts which is the harbor of caterpillars can be effective method of controlling *S. obliqua*. Also, planting trap crops like cowpea, castor and Jatropha on field bunds to attract the caterpillars may be efficient. Setting up bonfires on field bunds during night, mass collection and destruction of eggs and emerged larvae are mechanical ways of controlling hairy caterpillars. Spraying B.t is also advocated at 1 kg/ha where mulberry is not grown. Application of insecticides should be considered if the threshold is exceeded. Dust Lindan 1.3% and Fanvalerate 0.4% can use in the early stage of larvae. In addition, spraying Quinalphos 25 EC, Chlorpyriphos 20 EC or Endosulfan 35 EC recommended when the

**3.10** *Spilosoma* **(***Diacrisia***)** *obliqua* **(Walker) (Lepidoptera: Arctiidae)** 

also severely damage other oilseeds such as sunflower.

caterpillars are younger (Jasani, 2009; TNAU, n.d.-c).

observed (Bhubaneswar, 2008).

and determine the percentage of crop defoliation (TNAU, n.d.-c).

number of larvae on randomly selected plants in the field (Jasani, 2009).

damaged in central whorl (Bhubaneswar, 2008; Jasani, 2009).
