**3.4** *Aphis craccivora* **(Koch) (Homoptera: Aphididae)**

**Identification:** *A. craccivora* is known as groundnut aphid or cowpea aphid. The adult is about 2 mm long, pear shaped, green greenish brown or greenish black in color. The nymphs are dark brown and turns to shiny dark. Adults are mostly wingless but few winged forms also seen (TIFP, n.d.-a).

**Life cycle and damage**: Both nymphs and adults feed on the growing tips, tender foliage, flowers and growing pegs causing stunting and distortion of the foliage and stems. They excrete honeydew on which sooty molds develop. Aphids are also known to transmit peanut stripe virus and groundnut rosette virus complex. They have 12-14 generations per year (TIFP, n.d.-a). In the USA Peanut and its wild species show resistance to the groundnut aphid (Lynch, 1990). Bottenberg & Subrahmanyam (1997) stated that aphids in central Malawi were first recorded when the crop was at the flowering stage, but after 2 weeks the population of aphids decreased and the infestation ranged from 6 to 32%.

**Monitoring:** monitoring should be done during seedling, flowering and pegging stages of the crop. Monitor undersides of the leaves and yellow traps can use for monitoring aphids.

**Economic and action thresholds:** on average recorded in 1986, *A. craccivora* was of economic importance with economic threshold of 22.3 aphids per plant. However, the economic damage of aphids varies with the stage of plant, with most damage caused if aphids infest the growing points of groundnut early in the plant's development (CABI, 2011).

**Control**: releasing *Cheilomenes sexmaculata* (F.) or other biological control agents such as flower bugs (Anthocorids), and etc. would be effective in controlling aphids (Jasani, 2009).

#### **3.5** *Anisolabis stalli* **(Dohrn) (Dermaptera: Forficulidae)**

**Identification:** Pod borer adults are dark brown to black with forceps like caudal cerci and white leg joints. Nymphs are white in early stages and later turns brown (TNAU, n.d.-c).

**Life cycle and damage: y**oung pods showing bore holes plugged with excreta. Sand particles or discolored pulps is also observed and the pods lose their kernel (TNAU, n.d.-c).

**Monitoring:** monitoring can be accomplished with wheat bran or oat meal baits or traps. Likewise, traps take advantage of the natural tendency of earwigs to hide in crevices and can be used to detect presence of earwigs, and to estimate abundance (Capinera, 2009).

**Economic and action thresholds:** No action threshold has been set for pod borers.

Oilseed Pests 135

**Economic and action thresholds:** the economic threshold in south-central India for white

**Control:** planting tolerant varieties; deep ploughing in the summer; manual destruction of infested plant stems; treatment of the seeds before sowing with Chloropyriphos can control grubs population and their damage. The seeds can further be treated with fungicides like Thiram. Applying carbofuran granules in the planting row can be effective (Jasani, 2009).

**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

**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

**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

**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

such as Chlorpyrifos if the threshold is exceeded (Mossler & Aerts, 2009).

plant resistance has been confirmed to the *A. modicella* (Lynch, 1990).

**(Lepidoptera: Gelechiidae)** 

**3.9** *Stomopteryx submissella* **(Frey) and** *Aproaerema modicella* **(Deventer)** 

margin. The larvae are green in color with dark head and prothroax (TNAU, n.d.-c).

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

dark head, and a small dark spot at the rear (Mossler & Aerts, 2009).

grubs is observation of 0.14 larvae m-2 (Anitha et al., 2005).

**Control**: Application of Malathion 5D 25 kg/ha or Endosulfan 4D 25 kg/ha to the soil prior to sowing in endemic areas. Forty days after sowing, the application of insecticides should be repeated (TNAU, n.d.-c).

#### **3.6** *Odontotermes obesus* **(Rambur) (Isoptera: Termitidae)**

**Identification:** termites are social insects, live in territorial, in distinct castes, workers, kings and queen. Workers are smaller; have a soft, white body and a brown head (Jasani, 2009).

**Life cycle and damage**: termites are one of the major soil pests of groundnut. However, in the USA peanut and its wild species show resistance to the genus *Odontotermes* (Lynch, 1990). Termites favor red and sandy soils and lay eggs on plants or in the soil. They penetrate, hollow out the tap root and feed on the roots of the groundnut. The attack continues with boring holes into pods and damages the seed. It removes the soft corky tissue from between the veins of pods causing scarification, weaken the shells, and make them liable to entry and growth of *Aspergillus flavus* that produces aflotoxins (Jasani, 2009; Umeh et al., 2001).

**Monitoring:** for determining the presence of termites in the field insert two pieces of wood into a hole in the ground as monitoring devices at fixed intervals (typically 10 to 20 feet apart). If termites are found in the monitoring station, woods are replaced with a perforated plastic tube containing baits. After termites are no longer found in installed bait tubes, the baits are once again replaced with untreated wood pieces and monitoring continues.

**Economic and action thresholds:** No action threshold has been set for termites.

**Control**: cultural control techniques for termites are: digging the territorial and destruction of the queen and harvesting the groundnuts as soon as they are matured. Termites can be controlled mechanically by avoiding physical loss of the crop during harvesting, destruction of debris, nests and queen. Applying insecticides like Chlorpyriphos 20 EC, Lindane 1.3% or Chlorpyriphos dust in soil before sowing may reduce termite damage (Jasani, 2009).

#### **3.7** *Holotrichia consanguinea* **(Blanchard),** *Holotrichia serrata* **(F.) and** *Sphenoptera indica* **(Laporte & Gory) (Coleoptera: Scarabaeidae)**

**Identification:** The adult of *S. indica* is shiny beetle, about 10 mm long and 3 mm wide. The larvae are C shaped, slow movers having globular head and elongated, dorso-ventrally flattened body. Population takes place in the larval tunnel. Adults of *Holotrichia* spp*.* are about 18-20 mm long and 7-9 mm wide. The eggs are white, almost round. The young grubs are translucent, white and 5 mm long (Jasani, 2009).

**Life cycle and damage**: grubs are one of the major soil pests of groundnut. They are polyphagus and both adults and larvae are damaging stages. The females lay eggs singly on the main stem. The grubs live in soil and remain active, feed on the functional roots of the plant, leaving behind only tap root. They also burrow into the stem, close to the soil surface and kill the plant. Grub infested plants turn pale, leaves and branches drop down, the plant withers and can be easily uprooted. It ultimately dies off resulting in patchy crop growth (Jasani, 2009; Umeh et al., 2001).

**Monitoring:** install light traps in the field; with the onset of rains the beetles come out of the soil and attract to the light so count the number of beetles per day. Also, dig 10 pits per ha in 100 × 100 × 20 cm and count the number of beetles per pit every day (Jasani, 2009).

**Control**: Application of Malathion 5D 25 kg/ha or Endosulfan 4D 25 kg/ha to the soil prior to sowing in endemic areas. Forty days after sowing, the application of insecticides should

**Identification:** termites are social insects, live in territorial, in distinct castes, workers, kings and queen. Workers are smaller; have a soft, white body and a brown head (Jasani, 2009).

**Life cycle and damage**: termites are one of the major soil pests of groundnut. However, in the USA peanut and its wild species show resistance to the genus *Odontotermes* (Lynch, 1990). Termites favor red and sandy soils and lay eggs on plants or in the soil. They penetrate, hollow out the tap root and feed on the roots of the groundnut. The attack continues with boring holes into pods and damages the seed. It removes the soft corky tissue from between the veins of pods causing scarification, weaken the shells, and make them liable to entry and growth of

**Monitoring:** for determining the presence of termites in the field insert two pieces of wood into a hole in the ground as monitoring devices at fixed intervals (typically 10 to 20 feet apart). If termites are found in the monitoring station, woods are replaced with a perforated plastic tube containing baits. After termites are no longer found in installed bait tubes, the

**Control**: cultural control techniques for termites are: digging the territorial and destruction of the queen and harvesting the groundnuts as soon as they are matured. Termites can be controlled mechanically by avoiding physical loss of the crop during harvesting, destruction of debris, nests and queen. Applying insecticides like Chlorpyriphos 20 EC, Lindane 1.3% or

baits are once again replaced with untreated wood pieces and monitoring continues.

Chlorpyriphos dust in soil before sowing may reduce termite damage (Jasani, 2009).

*indica* **(Laporte & Gory) (Coleoptera: Scarabaeidae)** 

are translucent, white and 5 mm long (Jasani, 2009).

(Jasani, 2009; Umeh et al., 2001).

**3.7** *Holotrichia consanguinea* **(Blanchard),** *Holotrichia serrata* **(F.) and** *Sphenoptera* 

**Identification:** The adult of *S. indica* is shiny beetle, about 10 mm long and 3 mm wide. The larvae are C shaped, slow movers having globular head and elongated, dorso-ventrally flattened body. Population takes place in the larval tunnel. Adults of *Holotrichia* spp*.* are about 18-20 mm long and 7-9 mm wide. The eggs are white, almost round. The young grubs

**Life cycle and damage**: grubs are one of the major soil pests of groundnut. They are polyphagus and both adults and larvae are damaging stages. The females lay eggs singly on the main stem. The grubs live in soil and remain active, feed on the functional roots of the plant, leaving behind only tap root. They also burrow into the stem, close to the soil surface and kill the plant. Grub infested plants turn pale, leaves and branches drop down, the plant withers and can be easily uprooted. It ultimately dies off resulting in patchy crop growth

**Monitoring:** install light traps in the field; with the onset of rains the beetles come out of the soil and attract to the light so count the number of beetles per day. Also, dig 10 pits per ha in

100 × 100 × 20 cm and count the number of beetles per pit every day (Jasani, 2009).

**Economic and action thresholds:** No action threshold has been set for termites.

**3.6** *Odontotermes obesus* **(Rambur) (Isoptera: Termitidae)** 

*Aspergillus flavus* that produces aflotoxins (Jasani, 2009; Umeh et al., 2001).

be repeated (TNAU, n.d.-c).

**Economic and action thresholds:** the economic threshold in south-central India for white grubs is observation of 0.14 larvae m-2 (Anitha et al., 2005).

**Control:** planting tolerant varieties; deep ploughing in the summer; manual destruction of infested plant stems; treatment of the seeds before sowing with Chloropyriphos can control grubs population and their damage. The seeds can further be treated with fungicides like Thiram. Applying carbofuran granules in the planting row can be effective (Jasani, 2009).
