ABSTRACT

In the present study, the combination of neem oil extract with AgseGV tested against A. ipsilon neonate larvae enhanced the activity of GV, measured by the decrease of the LC₅₀ value from 3.59 x 10⁷ in the virus alone- treatment to 7.11 x 10⁶ capsule/ml diet in the treatment of virus and neem at 10ppm (5.0567fold). Present results also proved that the combination of neem oil with AgscGV decreased the LT₅₀ value about 1.938 fold; from 14.136 days in the virus alone- treatment to 7.295 days at virus concentration 3.85 x 10⁷ capsule/mi diet + neem (10ppm). The effect of neem on larval weight in present results was evident among the post-treatment survival A. ipsilon larvae. The observed reduction in larval weight (from 0.292676 gm / larva in the control treatment and 0.243376 in the virus alone- treatment to 0.003486 gm/larva in the combined treatment) is probably due to the act of neem as anti-feeding. The neem mode of action is explained by its effect on the digestive enzyme activity and the biochemical composition in the mid gut. One disadvantage of addition of Azadirachtin to viral formulation is less virus produced and released into the environment.