Vol. 12, Issue 5 (2023)

Author(s):
Shambhavi HT, Srinivas Reddy KM, Yamanura, Mohan Kumar R, Keshava Reddy G and Abhishek D Katteppanavar

Abstract:
Studies on population dynamics of insect pests of castor and their natural enemies were carried out at Zonal Agricultural Research Station, UAS, GKVK, Bangalore. A total of twenty insect species belonging to twelve families and five orders were observed during this study. Leafhopper activity started at seedling stage with peak incidence during 29^th Standard Meteorological Week (SMW) whereas, leaf miner, tussock caterpillar, thrips, castor semilooper, castor spiny caterpillar and whitefly reached their peak populations during 27^th, 31^st, 33^rd and 35^th SMW, respectively. Capsule borer activity peaked during 29^th SMW at capsule development stage. All the pests were negatively correlated with the maximum temperature, except for leaf miner and tussock caterpillar. The results of influence of minimum temp. were similar to that of max. temp., except for whitely population. The pests showed positive correlation with min. and max. relative humidity except leaf miner which was negatively correlated with min. RH and whitefly and tussock caterpillar whose population decreased with increasing max. RH. Sun shine hours favored the development of leaf miner but no other pests. Rainfall influenced leafhopper, thrips and castor semilooper negatively.