Population dynamics of predators in cashew

Abstract

Populations dynamics of three major insect pest predators was analysed in an organic cashew orchard at the Regional Fruit Research Station, Vengurle, during 2017. Amongst the predators, only spiders were observed throughout the year, with 0.05 to 1.40 spiders and spiderlings/shoot; maximum population was observed during first meteorological week with maximum and minimum temperature being 33.56 and 14.81°C, respectively, while the morning and evening relative humidity was 85.71 and 55.71%, respectively. The chrysopids and coccinellids were not observed throughout the year but occurred more or less regularly during 1st MW to 15th MW, their maximum larval population was during 5th MW i.e., 0.40 and 0.15/shoot, respectively. Maximum number of egg/egg masses of chrysopids (0.35/shoot) and coccinellids (0.15/shoot) was observed during 1st and 2nd MW. Adult chrysopids were observed during 11th and 13th MW, and coccinellids adults were observed irregularly from 2nd MW to 22nd MW and from 47th MW to 52nd MW. Correlation coefficients of the population of predators with weather parameters were statistically non-significant.