Insect Pests of Fruit, Plantation, Medicinal & Aromatic Crops (2+1)

4. Slug caterpillar - Conthyla rotunda H. (Cochlididae: Lepidoptera)

Damage

• The caterpillar feeds on leaves causing severe defoliation.
  
• Besides it also feeds and damages spathes, flowering shoots and rind of young fruits.
Bionomics

• The moth is greyish brown to dark grey in colour.
  
• It lays the eggs on the under surface of leaves.
  
• Fecundity is about 215 eggs / female.
  
• The egg period last for 3-6 days.
  
• The slug like caterpillar is spiny with two grey stripes dorsally.
  
• The larval period is 27-48 days.
  
• It pupates in shell like cocoon of brown silk for 10-14 days





Management

• Set up light traps to monitor and kill the adult moths.
• Spray the crown with carbaryl 0.1 % (or) dichlorovos 0.02 % or malathion 0.05 % solution.
• In severe cases, root feeding of monocrotophos as explained earlier under leaf eating caterpillar may be taken up with safety precautions.
• Collect all the stages of pests viz. eggs on tree trunks, leaves, larvae during migration stage, pupae in soil and leaf sheath and adult moth during emergence and destruction.
• Organise mass collection campaign involving farmers, school children and college students.
• Spray dichlorovos @ 2 ml / litre using specially designed tractor mounted tall tree sprayer.
• Dust methyl parathion or endosulfan dust @ 1 kg / tree using power operated bellowed crane duster to reach tall trees.
• Encourage the predatory birds to pick up the larval stages.