Groundnut

Insect Management

• The damages caused by insect pests of groundnut crop both in field as well in storage are enormous.
• An annual loss due to insect pests problem is estimated to be around Rs. 1500 million.
• In India, about 115 insect pest species cause damage, of which only 9 species (leafminer, white grub, jassid, thrips, aphid, tobacco caterpillar, gram caterpillar, red hairy caterpillar and termites) are found to be economically important.
• Leafminer is considered to be one of the national pests of groundnut in India. This insect pest has become a serious problem in Southern states, Maharashtra, Bhubaneshwar area of Orissa and Gujarat in both kharif and rabi/summer seasons.
• White grub is another pest of national importance and causes serious yield loss in the sandy loam soils of North India.
• This pest has also been reported to be occurring in Maharashtra (Digraj, Parbhani), Madhya Pradesh, localized areas in Andhra Pradesh, in north and north east Gujarat, and in areas surrounded by mountains of Dhencanal district of Orissa.
• Due to the menace of white grub, the groundnut area in the states of Uttar Pradesh, Rajasthan, Punjab and Haryana has shown declining trend.
• Major jassid problem is in Gujarat, Maharashtra and Tamil Nadu.
• Thrips are important pests of groundnut in Karnataka, Orissa, some parts of Maharashtra, Andhra Pradesh and Gujarat. Frankliniella schultzei is a vector of bud necrosis virus disease, Aphids are sporadic pests of groundnut in India although they are common in Maharashtra and Orissa states.
• Tobacco caterpillar has become an important pest only recently.
• At present it is a pest on irrigated groundnut in Andhra Pradesh, Karnatakaa and Tamil Nadu.
• It is becoming increasingly important during kharif in the states of Karnataka (Dharwad), Gujarat (Junagadh) and Haryana (Hissar).
• Gram caterpillar has become important recently in Andhra Pradesh, Karnataka and parts of Giujarat.
• Red hairy cater pillar has two species; Amsacta moorei dominant in North India and A. albistriga the most dangerous and destructive to groundnut crop in South India.
• Termites are serious pests of groundnut in West Bengal, Uttar Pradesh, Rajasthan, Gujarat, Haryana and Punjab.
• Correct identification of groundnut diseases and insect pests is the first step in planning a control programme.
• Fortunately, symptoms/injury can be used to identify most of the diseases and insect pests in groundnut.
• If signs or symptoms of the disease differ considerably from what is considered to be normal, a plant sample should be submitted for study and microscopic examination.
• New diseases do occur and minor diseases sometimes become wide spread.
• Special attention should be given to diseases and insect pests that occur consistently and cause heavy losses, since growers will benefit economically from their control.
• Keeping in view the hard facts that :
  1. The economic capacity of the groundnut farmer is limited,
  2. The damage caused by diseases and Insect pests to groundnut crop in field is much greater than most other cereal crops, and
  3. Resistant commercial varieties of groundnut are not avaialbel emphasis has been given on effective control measures for each of the economically important diseases and insect pests.

• Polyphagous pest, widely distributed.

• Nymphs are light yellowish green or greenish black or brownish.
• Adults are mostly wingless but few winged forms also seen. Winged and wingless forms breed parthenogenetically and hence population build up is quite fast.
• It has 12-14 generations per year.

• Cool and humid conditions are favourable for multiplication while heavy rains wash away the aphid colonies.
• Economic threshold limit is 15-20% affected plants.

• Dusting of Endosulphan 4% dust at 1 kg a.i./ha would be effective in controlling aphids.

• Coccinellid predators such as Cocciilella sezptumpunctata, Menochiles sexmaculata would be effective in reducing the population of aphids.

• Varieties which are densely hairy and with stiff leaves interfere with the build-up of aphid population.

• Mostly seen from November onwards when the groundnut plant enter into reproductive phase.

• Insect is very active in post - rainy season, (October to March) which coincides with reproductive phase of groundnut crop.

• Similar control measures can be taken up as in Tobacco Caterpillar.

• Damaged plants can be easily pulled out.

• Spray should be undertaken as a community approach and should be repeated after every rainfall till the middle of July.
• Seed treatment with Chlorpyriphos (Dursban 20 EC) @ 12.5 ml/kg seed or Isofenphos 40 SD has also been recommended.

• Rebuild up of pest population is slow.
• Foliage of economically important sprayed trees also gets protected, e.g. fruit trees like ber, apple, guava.

• Control of the jassids with insecticides is relatively easy.
• Spraying of Monocrotophos 0.05 per cent or Dimethoate 0.05 percent not only gave significantly superior yields but also resulted in the highest cost Benefit Ratio (CBR).

• There are few promising accessions like NCAc 2232, NCAc 2230, NCAc 2243, NCAc 2242, NCAc 2214, NCAc2240, NCAc 489, NCAc 1705, NCAc 2666, NCAc 343 etc., possessing resistance to jassids, but most of the resistant genotypes indentified are low yielders and mature 20-40 days later than common cultivars.
• However, cultivar NCAc 343 which possesses vertical resistance is fairly high yielder.

• Intercropping with pearl millet generally reduces the population of jassids in groundnut.
• However, groundnut-castor inter crop increases the infestation.

• The adult moths are attracted to light from 6.30 to 10.30 P.M. Petromax lamp placed at ground level attracts moths.

• Crop rotation with non-leguminous crops would considerably reduce the leafminer population.
• Rotation of groundnut with soyabean and other leguminous crops should be avoided.
• The most promising method of control would be utilization of resistant/tolerant varieties.
• However, we do not have a pest resistant variety at present in the country, although some resistant sources like NCAc 343, NCAc 2232 and NCAc 2230 showing multiple resistances are available.

• Though about 25 species of hymenopterous parasites were found to attack the leafminer eggs, larvae and pupae on groundnut, no large scale release and augmentation have been tried.

• Effective control with significantly increased pod yield could be achieved if insecticide is applied at 45 and 70 days after planting.
• The insecticidal control should be initiated when the larval population reaches 61-70 per 100 leaflets.
• Carbaryl 50WP 0.2 per cent spray was found to be most economical for controlling this pest.

• Collection and destruction of egg masses and hand picking of larvae are effective in reducing the larval population.
• The barnyard millet (Echinochloea frumentacea.) may act as strong barrier against hairy caterpillar when planted around the groundnut plot.
• Such a barrier reduces the cost of insecticidal use.
• For control of red hairy caterpillar use Integrated pest management methods like summer ploughing and poision baiting.

• 8 kg rice bran + 1 kg jaggery +1 liter insecticide
• Prepare small balls broad-cost in the fields preferably in the evening times.

• Dusting of Carbaryl or Parathion @ 25-30 kg/ha would be effective in the control of young larvae.
• Use of 200 ml Dichlorovos 100 EC dissolved in 400 litres of water/ha may be used to control grown up caterpillars.

• The dispersing larvae of hairy caterpillar from one field to another can be checked by digging trenches across the direction of their march, and prompt destruction of larvae.

• In groundnut the caterpillar mostly damage the leaves and stems.
• This is coincides with post rainy season viz., November onwards.

• When it is young it is generally green.
• Later it turns to dark green or violet.
• It pupates in the soil within 17-24 days, the adult moth comes out.
• The total life cycle is completed in 43-63 days.

• After December, particularly after heavy rains, heavy infestation develops.
• Larvae is polyphagous and appear on groundnut crop both in vegetative phase and at the time of pod formation.
• Among the pod borers, spodoptera litura is major and does maximum damage to groundnut crop.

• All the pod borers are nocturnal in habit and can be seen during day time also in the early stages. It is easy to control when they are seen in numbers on the same plant feeding on leaves making small holes.
• Spray Chlorpyriphos 3ml/litre of water or Quinolphos 2ml/litre of water or Acephate 1g/litre of water are recommended.
• Keep Phermone traps (2/acre) in the field to attract the male moths by which the intensity of pod borers in the environment can be known.
• Poison baiting with bran, Jaggery and chlorpyriphos (8:1:1 w/w) is promising against grown up caterpillars which withstand contact insecticides as sprays.
• In case the conventional insecticides fail to control the pod borers the usage of Synthetic pyrethroids is to be resorted to. Don't spray synthetic pyrethroids more than Twice, as they induce flare up of sucking pest complex.

• Seed dressing with insecticides such as Aldrin or Lindane may reduce terminate damage.
• Drenching with soil insecticides such as Aldrine at the localised spots will offer good control.

• Harvest the groundnuts as soon as they are matured.
• Early removal of the produce from the field will reduce the chances of termite damage to pods.

• More acceptable control measures would be to grow cultivars resistant to termite attack.

• Polyphagous and very widely distributed
• Starting from seedling stage occurs at all stages of crop growth.

• Both nymphs and adults lacerate and feed the sap from under surface of leaves and imbibe the oozing sap.
• Leaves loose the natural lustre the upper side of leaf turn brown and lower side becomes silvery white.
• Each female lay 60-70 eggs single into the green plant tissue 4-6 per day. Eggs hatch in 5 days.
• The nymphal period last for 5 days, pupal period for 4-5 days.
• Several generations found in a year.
• Economic threshold: 10 thrips/leaf.

• High temperature with low rainfall favours multiplication.
• Insecticides effective against aphids and Jassids are also effective against thrips.

• Insecticides such as Dimethoate, Methyldemeton and Monocrotophos at the rate of 1.5ml per litre of water gives control of thrips effectively.

• Several groundnut accessions like 21018 have been identified as resistant to thrips.
• The genotypes like NCAc 1705, NCAc 2230, NCAc 2232, NCAc 2240, NCAc 2242, NCAc 2243 and NCAc 343 were found to be promising.