Efficacy of biorational insecticides for the management of mealybug, Maconellicoccus hirsutus (Green) and spiralling whitefly, Aleurodicus disperses (Russel) and their safety to coccinellid beetles on guava

摘要

Field experiment on effectiveness of different biorational insecticides against mealybug (Maconellicoccus hirsutus Green) and spiralling whitefly (Aleurodicus disperses Russel) and their safety to natural enemies in guava were carried out at Experimental Farm, Division of Entomology and Nematology, IIHR, Bangalore, India during 2015-16. All the treatments were significantly superior over untreated check. Results indicated that the maximum reduction of mealybug population was recorded in the treatmentof organic salt 30 WS @ 5 ml/l (2.32 mealy bugs/three shoots) followed by spinosad 45 SC @ 0.2 ml/l (2.45 mealy bugs/three shoots) after first and second spray respectively. Whereas less population of spiralling whitefly was recorded in spinosad treatedplot (2.06 spiralling whiteflies/three leaves). Safety of natural enemy’s concern dimethoate 30 EC @1.6 ml/l, azadirachtin 10000 ppm @1 ml/l and Neem soap @ 10 g/l were found to be more harmful to coccinellid beetles and recorded very less beetle population, while Organic salt 30 WS @ 4 ml/l, L. lecanii @ 2 g/l and spinosad 45 SC @ 0.2 ml/l were the safest chemicals.