Insect Pests of Vegetable, Tuber and Spice Crops

Mustard sawfly

7. Mustard sawfly, Athalia lugens proxima (Tenthredinidae: Hymenoptera)

Distribution: All over the Indian sub continent.

Host range: Cruciferous crops

Nature of damage:

• It has a great potential to defoliate the crop plant at seedling stage.
• Adults inflict damage by act of laying eggs with the help of their saw like ovipositor.
• Larvae nibble margins of tender leaves and later bite holes in the leaves.
• Larvae generally feed during dawn and dusk

Identification:

Life cycle:

• Developmental periods (days):
• Egg: 6-8
• Larval: 20-30
• Prepupal: 3-4
• Pupal: 7-10
• Adult longevity: 10
• Fecundity: 100-170

Salient features:

• Winter season pest
• 1st appears on Radish during July-August
• Completes 10 generations in south India
• In North India, active from September- March
• Pupate in silken cocoons between leaves but before aestivation enters in soil
• 5 instars in male and 6 in female

Management:

• Hand picking of larvae and their destruction.
• Irrigation results in drowning of the larvae.
• Use of neem is also effective.
• Bt formulations @ 0.05- 0.2 per cent exhibits excellent control
• Application of quinalphos (0.025%) or malathion (0.05%) or dichlorvos (0.05%) is effective in controlling this pest.