Antifeedant and Repellent Properties of Clerodendron inerme and Polygonum orientale against Tea Mosquito Bug, Helopeltis theivora Waterhouse

Abstract

Antifeedant and repellent properties of different solvent extracts viz., chloroform, methanol and petroleum ether of Clerodendron inerme and Polygonum orientale at 5.0, 4.0, 3.0, 2.0, 1.5 and 1.0 per cent concentrations were studied against 1st instar nymphs of H. theivora. Both the plant extracts with chloroform gave the highest antifeedant property and repellency. The spots (179.50) produced by two nymphs within 24 hours were reduced to (18.25-35.50) and (24.50-41.50) with chloroform extracts of C. inerme and P. orientale at 5.0 - 1.0 per cent concentrations respectively. The other two solvent extracts also gave significant result. Likewise, the repellency was also observed and found that C. inerme with chloroform gave the highest repellency followed by petroleum ether and methanol extracts of the same. The other plant extract too showed highly significant (P=0.01) repellency compared to control.