Effect of various control measures on predator incidence and production performance in lac insect (Kerria lacca)

Abstract

In order to evaluate the efficacy of various predator control strategies and to see the influence of these measures on the production and profitability of Kusumi lac, a field study was undertaken in several sites of two lac-growing districts in Jharkhand, namely, Bokaro and Ranchi. Twenty lac farmers were divided into 4 groups: T1 (Farmers’ practice: no use of nylon net and/ or insecticide); T2 (Use of insecticide); T3 (Nylon netting) and T4 (Nylon netting with insecticide application). The Kusumi lac growers were identified for the data collection on predator incidence, lac yield and B:C ratio. The results showed that the number of predators/m encrustation for the predators like Eublemma amabilis and Pseudohypatopa pulverea was significantly (p<0.05) reduced in T4 after the third spray of the insecticide as compared to T1 (7.5 vs. 22.0 for Eublemma amabilis and 8.0 vs. 41.0 for Pseudohypatopa pulverea). The overall incidence of predators was significantly (p<0.05) reduced in T4 by 74.5% as compared to T1. The yield of lac was significantly (p<0.05) reduced in T1 as compared to T4 (20.0 vs. 65.0 kg/5 plants). Higher B:C ratio was found in T4 as compared other treatment groups. It can be concluded from the present study that the use of nylon netting (60 mesh) along with application of insecticide thrice (Ethofenprox 10 Ec. @ 2 ml/l) was significantly effective against the common predator insects of the lac and affected the productivity and profitability of the lac cultivation significantly.