Learn about how to control pests of pulse crops!
1. Greasy Cutworm:
Agrotis Ypsilon Rott. (Lepidoptera- Noctuidae):
It is commonly known as “greasy cutworm”, and is cosmopolitan in distribution. The attack is extremely serious during winter when young seedlings, roots and leaves are nibbled at night and the stems cut at the level of the ground by the caterpillars. Besides gram, it is also a pest of potato, tobacco, peas, cotton, tomato, vegetables and other winter crops. The caterpillars are polyphagous.
The moth is dark brown with a grey body, grey fore wings with dark brownish black markings. The hind wings are almost white basally but with a dark terminal fringe particularly in the males. They measure about 40-50 mm. along the wings. The moth is nocturnal.
Life History:
The female moth lays eggs in clusters, consisting of about 30 eggs in each underside the leaves. Several thousand eggs can be laid by a single female moth. The eggs are white, globular and ribbed, 0.5 mm. in diameter. The larva hatches in about 2-9 days and begins to feed on egg shell which forms the first meal of the larva. The larvae are also nocturnal and they remain underground in day time.
The full grown caterpillar measures about 35-45 mm. long, is dull grey or brownish in colour. Larval development takes 28-34 days. The pupae are dark brown, 20 mm. long. Pupation takes 10 to 30 days or more depending on the temperature and then moth emerges and starts new life cycle. The life cycle from egg to adult takes about 32 days at 30°C and 67 days at 20°C.
Control:
Removal of weeds from the field helps to eliminate oviposition sites. Fenitrothion has generally given best control of many cut worm species.
The pest can be controlled by application of endosulfan 5% dust @ 25 kg/ha or thiodan 0.05% spray.
2. Gram Cutworm:
Agrotis Flammatra Schiff. (Lepidoptera- Noctuidae):
The gram cutworm is one of the most important pests of gram in India. It is a polyphagous pest and besides gram, it feeds on a wide variety of plants belonging to different families. The adult moth is a stout, greyish brown in colour measuring about 5-6 cm. in wing expanse.
The fore wings of the moth have characteristic markings and smoky patches, the proximal areas being pale or yellowish in colour. Each wing is provided with a semi-circular spot below the pale or yellowish area and a greyish-brown kidney shaped spot towards the apical area. The damage is caused only by the caterpillars.
Life History:
The moths lay yellowish white eggs on the underside of the leaves, on shoots, stems or in the soil within 5-10 days of their life which is about 7-13 days only. A female moth lays about 950 or more eggs in her life time. Hatching takes place in about 4-14 days depending on the temperature. The larvae are full grown in about 4-7 weeks and measure 40-50 mm. in length, dark grey or light green in colour.
They pupate in the earthen cells constructed by them in the soil. The pupal stage lasts about 10-15 days in favourable weather but during winter it extends upto 5 weeks or more and after which the moth emerges. The whole life cycle is completed in about 6-13 weeks, depending on the climatic conditions. There are usually 2 generations in a year.
Control:
The pest can be controlled with lindane dust 2%. Cutworms can also be controlled by spraying of 35 EC endosulfan in the concentration of 2 ml/litres of water at 15 days intervals. Two or three sprayings are sufficient.
3. Gram Pod Borer:
Heliothis Armigera (Hubner) (Lepidoptera- Noctuidae):
The “gram pod borer” is universally distributed and is a polyphagous pest. It is one of the most serious pests of gram. The insect has also been found damaging many other crops like tomato, ground nut, tobacco etc. In U.S.A. and other countries it is a serious pest of corn and is known as “cornearworm” or cotton and is called cotton bollworm.
The adult is a stout built Noctuid moth with a wing span of 30-40 mm. The colour of moth varies from olive grey to red brown. The forewing has a dark speck and a dark area near the outer margin. The hind wing has a distinct smoky dark outer border. The damage is caused by the caterpillars.
Life History:
Eggs are laid singly on the tender parts of its food plants. The eggs are spherical, sculptured and with greenish shine when laid and measure about 0.5 mm. in diameter, as the embryo develop the eggs turn brown. Depending on temperature the egg period lasts from a few days to more than a week. Each female may lay about 1000 or more eggs in her life time.
The young larvae begin to feed on the tender portions of the leaves and shoots. Later, the caterpillars feed on the developing seeds after cutting hole in the pod with head inside but with the posterior part of the body outside the pod. They also burrow into the large pod and eat developing seeds. Their colour and size vary considerably. For example, the colour pattern consists of variable combinations of pale- green and pale-brown with longitudinal stripes along the sides.
The full grown larva measures about 35-40 mm. in length. The larval period lasts about 2-3 weeks. Full grown larva burrows into the soil and pupates there in an earthen cocoon. The pupa is shining dark brown in colour measuring about 12-16 mm. in length. The moth emerges in about 10-14 days after pupation. Egg laying starts about 4 days after emergence and may continue for about 9 weeks or more. There may be as many as eight generations in a year.
Control:
It can be controlled effectively by spraying the crop with 0.1% carbaryl or 1.5 litres of endosulfan 35 EC or 750 ml monocrotophos 40 EC/ha in 1000 litres of water. The caterpillars can also be collected and destroyed by simple hand picking. Crop rotation is also extremely useful.
4. Red Gram Pod Fly:
Agromyza Obtusa Mallas (Diptera- Agromyzidae):
It is a small metallic black fly which is also known as Tur Pod fly. The damage is caused only by the tiny maggots which bore into the pods and feed on the red-gram seeds. It is distributed throughout the red gram grown area of the India.
Life History:
The fly thrusts its minute eggs into the shell of a tender pod. The maggots hatch in about 3-4 days, and after feeding under the epidermis for some time they enters the seed. They become full grown in about 5-10 days. Pupation takes place within the damaged pods.
The pupal period lasts 7-11 or more days depending on the climatic conditions. The adult flies emerge by cutting holes. The entire life cycle is completed in about 9-30 days depending on the prevailing temperature. There are several generations in a year.
Control:
The pest can be controlled by spraying the crop with 1.5 litres of endosulfan 35 EC or 750 ml monocrotophos 40EC in 1000 litres of water/ha or dusting with 5% carbaryl or 5% endosulfan.
5. Tur Plume Moth:
Exelastis Atomosa Walsh. (Lepidoptera- Pterophoridae):
This is a very specific pest which prefers only the red gram. It occurs in most of the regions of India growing red gram (Tur or Arhar). The damage is caused by the caterpillars. The caterpillar cuts a hole in the red gram pod opposite to a seed developing inside and then inserts its head in that hole and feeds from outside on the developing seed. When one seed is consumed, the larva leaves that hole and cuts another opposite, to another developing seed.
Thus, it damages quite a high percentage of developing seeds which cannot be replaced and are thus totally lost. The adult is a small (about 7 mm. in length and 15 mm. wing span), beautiful greenish brown plume moth, as its name indicates. The wings, each of which consists of several longitudinal fringe like filamentous lobes, constitute the plume and they are gracefully held together on either side at right angles to the body of the moth when it is at rest.
Life History:
The female moth lays about 17-19 eggs singly on the tender pods of the food plant. The eggs hatch into tiny larvae about 1mm in length in about 2-5 days. The larvae feed on the pods and became full grown in about 2-4 weeks and measure about 7 mm. long. The colour of the larva is a variable combination of green and brown tinge. Pupation takes place outside the pod on its surface or in the entrance hole of the pod. The pupal period lasts from 3 days to more than a week and the whole life cycle is completed in about 15-40 days depending on the prevailing temperature.
Control:
This pest can be controlled by spraying the crop with endosulfan 35 EC (2 ml in 1 litre of water) @ 800-1000 litres/hectare or dusting with 5% carbaryl. The treatment should be given when the pod formation starts and the larvae are found feeding them.
6. Lentil Pod Borer:
Etiella Zinckenella Treit. (Lepidoptera- Phycitidae):
The Lentil pod borer is a serious pest of lentils as well as green peas both and is also found on a variety of other pulse crops in different parts of the country. The moths are grey with a wing expanse of 25 mm. The fore wings have dark marginal lines and are interspersed with ochreous scales.
Life History:
The female moth lays 50-100 eggs either singly or in clusters on the various parts of the plants. The eggs hatch in about 5-35 days depending on the prevailing temperature. The newly emerged tiny greenish larvae enter the pods and eat away the young seeds. The full grown larvae are rosy in colour with a purplish tinge. The larval stage is completed in about 10-27 days.
Pupation take place in the soil at a depth of 2-4 cm. The pupal development is completed in about 10-15 days depending on the climatic conditions, there after the moth comes out from the pupal case and starts the new generation. There are about 5 or more generations in a year.
Control:
The pest can be controlled by spraying the infested crop with methyl demeton 0.05% or monocrotophos 40EC @ 1 ml/ litre of water. About 600-800 litres of this solution is needed for spraying 1 hectare.
7. Pea Leaf Miner:
Phytomyza atricornis Meigen (Diptera- Agromyzidae):
The pea leaf miner is distributed throughout the world but in India its activity is confined to temperate seasons. The adult is a tiny fly, about 1.5 mm. in length and with a wing span of less than 4 mm. The flies are blackish-grey or silvery in appearance. The larvae are destructive and they make prominent zigzag silvery tunnels in the leaves.
An interesting point about the habit of this fly is that it combines the action of feeding and oviposition. It punctures the tender leaves with its ovipositor and then turns round to feed on the plant juice exuding from the puncture. The males are devoid of ovipositor and therefore cannot puncture, wait in attendance near the female to lick the juice after the latter have left the place.
Life History:
Each female fly makes numerous punctures on each leaf. The fly oviposits in the puncture, and lays one egg in each cavity. Each female fly is capable of laying about 350 eggs in its whole life span which may extend to near about one month. The eggs are extremely small, about 0.3 mm. in length and oval-elongate in shape. The eggs hatch within 2-5 days into tiny maggots which begin to feed on the mesophyll of leaf without damaging the two epidermal layers.
This leads to the formation of zigzag silvery galleries. Within 4-12 days the larva develops to its full size of about 3 mm. and then pupates within its last larval skin which hardens in due course. The pupa becomes reddish-brown or dark-brown in colour. The pupal period ranges from 6-16 days after which the fly emerges to start another generation. There are several generations in a year.
Control:
The collection of damaged portions of the plant when the attack is just started so that the attack can be nipped in the bud and further multiplication is checked. Poison baits against the adult flies have also been recommended. The pest can be controlled with spraying any one of these insecticides on the crop- dimethoate 0.02%, carbaryl 0.1% or dimecron 100 EC @ 250 ml/ha or metasystox 25 EC @ 1 litre/ha in 1000 litres of water. All the pests of pulses can be controlled by spraying endosulfan 35 EC @ 1 litre/ha or phosphamidon @ 250 ml/ha mixed in 1000 litres of water.