Insect Management

Introduction Blister Beetle Plume Moth Pod Borer Pod Fly Spotted Pod Borer

Insect pest problems of redgram and their control in Karnataka


  • Pigeonpea (Cajanus cajan L.) known by the common names redgram, tur and arhar. It is the second most important pulse crops of India after chickpea. It is grown mainly in the states of Uttar Pradesh, Madhya Pradesh, Maharashtra, Karnataka, Bihar, Gujarat, Tamil Nadu and Andhrapradesh.
  • The productivity of pigeonpea in Karnataka ia low. This lower yield was due to growing on drylands that too on marginal and submarginal lands with poor management practices.
  • Heavy flower shedding and poor pod setting and incidence of pests and diseases are also the causes for lower yields.


Blister beetle: Zonabris pustulata (Mtoloidae: Coleoptera)

  • This insect is noted to feed on the flower of many including all the pulse crops. The adult is black elongated shiring beetle, elytra with characteristic wavy reddish bands. Eggs are laid in the soil, the group pupate in the soil.

Nature of damage

  • Beetles appear in large numbers during flowering season and damage the flowers by feeding on petals.


  • Three sprays or dust should be given once in 10-12 days after emergence, ie.,
  • Endosulfan 30 EC 0.07 per cent or
  • Monocrotophos 36 SL 0.04 per cent or
  • Quinalphos 1.5 per cent dust 25 kg/ha.


Redgram plume moth : Exelastis atomosa (Peterophoridae: Lepidoptera)

  • This insect is almost a specific pest of redgram in many parts of India.
  • Adult is a slender small moth, wings are grayish coloured, narrow and prinked into lobes, which resemble plumes. It lays minute single eggs on the tender shoots or pods. The larvae is greenish-brown in colour and covered with short hairs and spines. The grownup larvae pupates on the grown pod surface or even on the burrow of the infested pod. The pupa is also covered with shoot hairs and spines.
  • The egg, larval and pupal periods occupy respectively 4, 14-30 and 4-8 days.

Exelastis atomosa adult

E. atomosa larva (green) and puma (brown)

  • The caterpillar bores typically by biting through the post and feed on the seeds inside.


  • Application of dust of phosalone 4 per cent or emulsion of phosalone 0.07 per cent or Endosulfan 0.07 per cent three times at fortnightly intervals commencing from flowering affords protection.
  • Dusting of Endosulfan 4 per cent or corboryl 10 per cent dust at 25 kg/ha once at initiation of flowering.


Important insect pests

The gram pod borer : Helcoverpa armigera (Noctoidae: lepidoptera)

  • This insect is found throughout the country and is polyphagous in its habits. It attacks cotton, redgram, maize, tobacco and many other important pulse crops.
  • The adult moth is yellowish brown in colour the moth has 'V' shaped speck on the forewings and a dark border on the hind wings. It lays spherical yellow eggs singly on tender parts of the plants.
  • The colour of the caterpillar is variable through generally, it is green having light longitudinal or grey streaks along the sides. The body surface has short setae. The grown up caterpillars pupates in an earthern cocoon in the soil. The egg, larval and pupal periods respectively are 2-4, 18-25 and 6-21 days

Nature of damage

Male (down) and female (above) pod borer adults

H. armigera eggs on pigeonpea flower buds

H. armigera damaging pigeonpea leaves and pods

  • The larvae feed on leaves, flower bud, flowers and pods. As a pod's borer it is often found exposing its posterior half with its anterior portion inside the pod. The damaged pods exhibits clear circular entry holes.
  • IPM in pigeonpea or Redgram pod borer Helicoverpa armigera

Cultural methods

  • Deep ploughing soon after the harvest of the crop to expose the pupae to sunlight.
  • Growing open flower and early maturing varieties to escape the incidence of H.armigera.
  • Growing of varieties at one time before 15th July results in avoiding the incidence.
  • Use ICPL 332 pigeonpea variety in Helicoverpa infested area.
  • Should not apply excess Nitrogenous fertilizers.
  • Crop rotation with non hosts.

Mechancial methods

Manual shaking of pigeonpea to dislodge Helicoverpa larvae

  • Shake the plants, collect the caterpillers and destroy.

Physical method

Birds feeding on caterpillars

  • Setting pheromone traps (6-8 traps/ha) to monitor the post incidence
  • ETI: 10 male moths/trap, pheromone lure will change once in a month.

Biological Control

  • Spraying of Nuclear polyhedrosis virus (NPV) 250 LE/ha along with 0.1 per cent teepol + 5 per cent boric acid + 0.5 per cent jaggery + 1000 litres were sprayed in evening hours at 10 days intervel for 3-4 sprayings. 23 spraying of Dipel 2 ml/litre.
  • Spraying of Neem seed kernel extract (NSKE) 4 per cent


Quinalphos 25 EC 0.05 per cent or

Endosulfan 35 EC - 0.07 per cent or

Chloropyriphos - 0.05 per cent or

Methylporathion - 0.05 per cent

(3 spray-ings starting from flower bud formation stage).
Quinalphos 1.5 per cent dust or

Malathion 5 per cent dust or

Femualorate 0.4 per cent dust

(25 kg/ha)


Redgram pod fly : Melonagromyza obtusa (Agrompidae: Diptera)

  • This insect is considered to be one of the most important pests of redgram as it is capable of inflicting upto 80 per cent losses in yield of seeds.
  • The adult fly is small. In appearance it resembles a small housefly. Body is metallic black in colour. Eggs are inserted into tender pods. Maggots are white and legless. The grown up maggot pupate inside the pod.
  • A female may lay eggs upto 70. The egg, larval and pupal periods occupy respectively 3, 9-10 and 8-5 days.

Nature of damage

Melangromyza obtusa adult

M. obtusa larva, and puparia, in a damaged pod

  • The maggot feed on the seed and destroys the same.


  • Same as that of plume moth


The spotted pod borer: Maruca testularis (Pyroustidae: Lepidoptera)

  • This insect is gaining importance in India, after the introduction of Cowpea varieties. In recent years, it is causing severe damage on redgram during certain years.
  • The moth has a white cross bond on the dark brown forewings, a dark border on the white hind wings. Eggs are laid on the undersurface of leaves or on pods in groups. The eggs are green scaly, oval in slope. The larva is green in colour with a brown head. There are block spots on the body with short dark hairs. The grownup larvae pupates in a thick silken cocoon on the pod or leaf fold.