Chronic effect of Melia azedarach seed extracts on survival, feeding, growth and development of helicoverpa armigera

Larvae of Helicoverpa armigera that fed on the artificial diet incorporated with Melia azedarach seed extracts produced a range of adverse effects that were dose dependent. Maximum antifeedance (AI₅₀) was caused by methanol extract (0.0146%), followed by hexane extract (0.0203%), ethyl acetate extract (0.0441%), butanol extract (0.0660%) and aqueous extract (0.0876%). Cumulative larval mortality ranged from 16.6 to 83.3% in different extracts. Fifty % larval growth inhibition recorded at 3 days after treatment was statistically at par with methanol and hexane extracts. The % inhibition (I₅₀) of normal adult emergence in methanol, hexane, ethyl acetate, aqueous and butanol extract was 0.0098, 0.0128, 0.0221, 0.0297 and 0.0460. Amongst the various extracts evaluated, methanol extract caused more antifeedace, larval toxicity and affected growth and development of H.armigera.