Effect of Insecticides on Different Developmental Stages of Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae), a Parasitoid of Solenopsis Mealybug, Phenacoccus solenopsis Tinsley

Abstract

Experiments carried to assess the effect of different insecticides, namely, profenophos 50EC (1.5g a.i./ha), thiodicarb 75WP (1.12g a.i./ha), quinalphos 25EC (1g a.i./ha), novaluron 10EC (0.1g a.i./ha), spinosad 45SC (0.18g a.i./ha), imidacloprid 200SL (0.6g a.i./ ha) and nimbecidine EC (0.03% Azadirachtin) (5 ml/litre of water) which are recommended in the cotton crop for the control of various insect pests, on different stages of solenopsis mealybug parasitoid, A. bambawalei under laboratory conditions has revealed that profenophos, quinalphos and thiodicarb were found to be most toxic (100% mortality within 24h after exposure) to the adults of A. bambawalei followed by imidacloprid (54%), novaluron (42%), spinosad (36%) and nimbecidine (10%). Number of mummies formed was lowest (2) when larval stage (in two days old parasitised mealybugs) of the parasitoid was sprayed with quinalphos while it was highest (40.20) when sprayed with novaluron followed by imidacloprid (38.60) and nimbecidine (30). Very low adult emergence was recorded when pupal stage (in five days old mummies) was sprayed with profenophos (5.40%) and quinalphos (4.70%) while highest (86.06%) adult emergence was recorded when sprayed with novaluron followed by imidacloprid (82.14%), nimbecidine (76.60%) and thiodicarb (60.60%).