Monday, September 29, 2014


1. Tomato fruit borer
Helicoverpa armigera
Family: - Noctuidea
Order: - Lepidoptera

  • Economic importance
Pod borer, aphids and pulse beetle are the important pests of this crop. Besides, cutworms and leaf eating caterpillars also damage this crop.
  • Marks of Identification
The moths are light yellowish-brown about 25mm in length and 37mm in wing expanse. Forewings are pale brown with black. Hindwings are lighter in colour having smoky dark margins. Full-grown caterpillars are greenish with dark broken grey along the sides of body, measuring 31 to 50mm in length.
  • Nature of damage
Caterpillars feed on tender foliage and young pods. They make holes in the pods and feed on developing seeds by inserting anterior half portion of their body inside the pods.
  • Host plants
It is a polyhagous species gram, cotton, tomato, peas, tobacco, ganja and sunflower are some of the important host plants.
  • Life history
Shinning greenish yellow spherical eggs are laid singly on the tender parts of plants. They hatch in about 6-7 days. On hatching the caterpillars start feeding on tender leaves and shoots. After pod formation they bore into them and feed on developing grains. Larvae become full-grown in 14 to 15 days. Pupation takes place in earthen cocoons in soil near the plants. Pupal period lasts for about 1 to 4 weeks. A generation is completed in 4 weeks. The pest is active from November to March and hibernates in the pupal stage till next season.
  • Control measures
In early stage of attack handpicking of the caterpillars and their destruction, help in reducing the intensity of infestation. Ploughing fields after the harvest of crop would expose the pupae, which would be destroyed by birds. The pest can be successfully controlled by spraying the crop with 0.05% quinalphos or fenitrohion. Spray with HaNPV @ 250 LE/ha.
2. Cut worm
Agrotis ypsilon R.
Family: -Noctudiae
Order: - Lepidoptera

  • Economic Importance
The cutworms are cosmopolitan insects and have been reported to occur throughout the country and particularly serious in low lying areas which remain water logged for considerable injury is done by Agrotis ypsilon to potato crop in India. The damage to the crop varies from 12 to 35%.
  • Marks of Identification
Moth is medium sized (22-26mm longer), stout with grayish brown wavy lines and sports on fore wings and creamy white wings. The moths are active at dusk and are attracted by light. Full-grown caterpillars are 40-48mm long dirty black in colour and have habit of coiling at slightest touch.
  • Nature of damage
The caterpillars hide during the day in cracks and crevices in the soil or in debris around the plants and feed on tender leaves of shoots during night by cutting them near the ground level. The destruction is much more than actual feeding.
  • Life history
A female lays 300-350 eggs (maximum 1800) in 10-15 clusters of 20-35 eggs on ventral leaf surface or moist soil. The incubation period is 4-7 days. Larval period lasts for about 3-5 weeks pupation takes place in the soil and moths emerge from pupae in 11-18 days. A generation is completed in 5-9 weeks.
  • Host plants
It is a polyphagous insect and feeds on potato, pulses, barley, oats, tobacco, peas, gram, cotton, tomato, lucerne, chilies, brinjal and other vegetables.
Control measures

  • Heaps of green grasses may be kept at suitable interval in infested field during evening and next day early in the morning alongwith caterpillars to destroy.
  • Clean cultivation and mechanical destruction of caterpillars also help in reducing pest infestation.
  • Irrigation also brings them on the surface and birds shall predate them.
  • 5% Carbaryl poison bait at the rate of 25-60kg/ha controls the pest effectively and
  • Soil application of chlordane or Heptachlor dust at the rate of 50kg/ha found effective against the pest.

Fruit borer in Brinjal

Shoot and fruit borer: Leucinodes orbonalis
Symptoms of damage
  • Withering of terminal shoots/ dead hearts
  • Bore holes on shoots  and fruits plugged with excreta
  • Shedding of flower buds
  • Withering and drying of leaves


Identification of pest
  • Eggs  -  Creamy white eggs
  • Larva -  pink in colour
  • Pupa- greyish boat shaped cocoon
  • Adult-   a medium  sized moth
  • Forewings- having black and brown patches and dots on white colour
  • Hind wings – opalescent with black dots
Management
  • Remove the affected terminal shoot showing boreholes.
  • Remove the affected fruits and destroy.
  • Avoid continuous cropping of brinjal crop
  • Grow the varieties with long and narrow fruits in endemic areas
  • Install pheromone trap@12/ha
  • Encourage the activity of larval parasitoids:
      • Pristomerus testaceus
      • Cremastus flavoorbitalis
  • Avoid use of synthetic pyrethroids
  • Avoid using insecticides at the time of fruit maturation and harvest
  • Neem seed kernel extract (NSKE) 5 % or any one of the following chemicals starting from one month after planting at 15 days interval
Insecticide Dose
Azadirachtin 1.0% EC (10000 ppm) 3.0  ml/lit.
Azadirachtin 0.03 % WSP (300 ppm) 5.0  g/lit.
Chlorpyrifos 20 % EC 1.0  ml/lit.
Dimethoate 30 % EC 7.0  ml/10 lit.
Emamectin benzoate 5 % SG 4 g/10 lit.
Flubendiamide 20 WDG 7.5 g/10 lit.
Phosalone 35 % EC 1.5  ml/lit.
Quinalphos 25 % EC 1.5 ml/lit.
Thiodicarb 75 % WP 2.0 g/lit.
Thiometon 25 % EC 1.0 ml/lit.
Trichlorofon 50 % EC 1.0 ml/lit.
Triazophos 40 % EC 2.5 ml/lit.