Field evaluation of inundative release of Chrysoperla carnea (Stephens) against pest complex of cotton

Abstract

To assess the impact of inundative release of Chrysoperla carnea (Stephens) against cotton pests a field experiment was conducted at college farm, B. A. College of Agriculture, Anand Agricultural University, Anand (Gujarat) during 2000-01 to 2002-03. Experimental results concluded that one (14000 larvae/ha) and two (28000 larvae/ha) releases of C. carnea significantly suppressed the population of aphid, Aphis gossypii G, leaf hopper, Amrasca bigutulla bigutulla Ishida and white fly, Bemisia tabaci Gen. Similarly, the incidence of spotted bollworm Earias sp. to developing buds and green bolls also reduced and increased the yield of seed cotton. Significantly highest (1949 kg/ha) yield was found in case of two releases over one release (1558 kg/ha) as against 1287 kg/ha in case of control (without release). Economics of different treatments evaluated revealed that relatively higher (1:1.87) Incremental Cost Benefit Ratio (ICBR) was found in case of two releases of chrysopids while single release of chrysopids exhibited 1:1.35 ICBR value.