Management of predators and parasitoids in lac culture through broodlac treatment using novaluron and Bacillus thuringiensis Var. Kurstaki

The safety of novaluron and Bacillus thuringiensis var. kurstaki formulations was evaluated against lac insect Kerria lacca (Kerr) and for their efficacy against associated predators and parasitoids. Four concentrations of novaluron 5% EC viz., 0.00125, 0.0025, 0.005 and 0.01% a.i. and two concentrations of Bt formulations, 0.34 and 0.51% a.i. were evaluated by dipping of broodlac (functional seed of lac culture) in insecticidal formulations for 5, 10 and 15 min. Non-significant differences amongst these treatments about survival of settled second instar larvae clearly indicated the safety of these insecticides to lac insect. Treatment of broodlac in insecticidal formulations for 5, 10 and 15 min duration exerted significant reduction in the population of lepidopteran predators Eublemma amabilis Moore (Noctuidae) and Pseudohypatopa pulverea Meyrick (Blastobasidae) which infest broodlac. The treatment of rangeeni broodlac with 0.0025% a.i. novaluron for 5 min resulted in significant reduction in the population of E. amabilis, P. pulverea and Tachardiaephagus tachardiae (parasitoid of lac insect). Dipping of rangeeni broodlac in B. thuringiensis kurstaki formulation (0.34%a.i.) also resulted in significant reduction in E. amabilis and P. pulverea populations. The treatment of kusmi broodlac with 0.005% a.i. for 5 min duration provides effective control of both key predators. Novaluron and Bt formulations can be safely and effectively integrated through broodlac treatment in IPM programme of lac production system.