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

Bud borer

1. Bud borer, Helicoverpa armigera (Noctuidae: Lepidoptera):

• Distribution: Cosmopolitan and widely distributed throughout India.
• Hosts: Polyphagous and attacks hosts like chickpea, pigeonpea, pea, mungbean, urdbean, lentil, soybean, cowpea, tomato, carnation, cotton, sorghum, okra, maize, sunflower etc.

Damage:

• Damage is caused by the caterpillars
• They bore into the developing buds and feed on petals inside them
• Infested buds never open and dry as such
• Partially damaged buds open into deformed flowers
• Infestation coincides with the bud initiation and peak activity is between March and June.

Identification

• Eggs are small, round, pale yellow
• Adult moths are stoutly built and are yellowish brown
• Darker area near the outer margins of the forewing.
• The forewings are marked with greyish wavy lines and black spots of varying sizes on the upper side
• The hind wings are whitish and lighter in colour with a broad blackish band along the outer margins
• Caterpillars are grayish to green with broken grey or green lines on lateral sides depending upon the host on which they feed.
• Pupae are dark brown in colour.

Life cycle:

• Eggs hatch in 2-4 days
• Larva becomes full fed in about 15-20 days
• Six larval stages
• Pupal period lasts for 8-15 days
• Adult longevity is 8-12 days

Salient features:

• Eggs are laid on closed and half opened buds
• Newly emerged larva enters the bud and feed inside
• Full grown larva enters the soil for pupation
• The infestation coincides with the bud initiation
• Peak activity is between March and June.

Management:

• Spray the crop with deltamethrin (0.0028%) at the time of bud formation
• Spraying should be done during evening hours to hinder the activity of adult moths
• Btk (Dipel) @ 0.5kg/ ha
• NSKE 4%
• Trichogramma spp

2. Phytophagous mites, Tetranychus sp.

• Discussed under the pests of rose.