Insect Pests of Vegetable, Ornamental and Spice Crops (2+1)

Tomato fruit borer

1. Tomato fruit borer, Helicoverpa armigera (Noctuidae: Lepidoptera)

Distribution: Cosmopolitan in distribution

Host plants: Polyphagous, infests over 100 host plants including chickpea, cotton, caster, tomato, cowpea, millets, linseed, tobacco, safflower, pigeon pea, okra, carnation etc.

Damage:

• Damage is caused by the larva
• Feed on the foliage, flowers, buds and fruits.
• Small green fruits are preferred
• Single larva can destroy many fruits
• The damage is more pronounced during March to June

Identification:

• Eggs: yellowish white, ribbed, dome shaped and 0.4-0.5 mm in dia.
• Larvae: Newly emerged are yellowish white where as older can be of many colours depending upon the food they consume. Full grown caterpillars are 40-48 mm long with whitish and dark gray longitudinal stripes.
• Adults:
• Medium sized stoughtly built moths.
• Forewing is light yellow in males and brown in females.
• On the apical margin of forewings, wavy lines in the form of light black band are visible and a black spot appears on the upper side of the wing.
• On the tip of the abdomen there is a tuft of hairs in case of females, nevertheless, the tuft of hairs is absent in males.

Life cycle:

• Incubation period: 2-5 days
• Larval period: 15-22 days
• Prepupal period: 1-2 days
• Pupal period: 10-14 days
• Adult longevity: 6-10 days
• Fecundity: 300-800 eggs

Salient features:

• Eggs are laid singly on leaves, flower and fruits.
• Young larvae feed on tender foliage and older bore fruits
• Caterpillars thrust only a part of their body inside the fruit and feed on the inner contents.
• Single larva can destroy 2-8 fruits
• Partially damaged fruits are attacked by other microbes
• The caterpillars are cannibalistic.

Management:

• Use of resistant varieties like Punjab Kesari, Punjab Chhaura, Pant Bahar, Azad, Pusa Hybrid-4 etc.
• Deep summer ploughing to expose the pupae to the sunlight and natural enemies.
• African marigold as trap crop.
• Pheromone traps (5 traps/ ha) of moths for monitoring
• Monitoring of top three leaves for egg laying
• Spray of HaNPV @ 250 LE/ha at weekly intervals
• Bt formulation @ 0.5 Kg/ha.
• Periodic releases of egg parasitoid, Trichogramma chilonis or T. pretiosum @ 100000 /ha.
  
• Spray of NSKE @ 4.0 per cent
• Emergency spray of cypermethrin (0.0075%) or deltamethrin(0.0028%)
• Natural enemies like Campoletis chloridae, Bracon brevicornis and Trichogramma spp are active in nature