PEST STATUS OF THE GRAIN SUCKING BUG, STENOCORIS ELEGANS BLOTE (HEMIPTERA: ALYDIDAE) ON RICE AND ITS SURVIVAL ON WILD HOSTS

Abstract

Determination of the pest status of an insect on a crop is an important step in decision making for effective pest management. Pest status of rice grain sucking bug (RGSB), Stenocoris elegans on rice, Oryza sativa was carried out by infesting rice panicles with 0 to 10 RGSB adults between 3 to 15 days after emergence, while development and survival of RGSB were investigated on rice, O. sativa and five other grass species. Treatments were arranged in a Completely Randomized Design with four replicates. Data were collected on the yield and damage of rice grains; and on nymphal developmental period, fecundity and longevity of S. elegans on each food hosts. Rice grain yield reduced significantly at population densities of 6 - 10 RGSB on rice panicles between 3 and 9 days after emergence. Grain damage increased significantly with increase in RGSB population but reduced with increase in the age of panicles. Nymphal developmental period of RGSB was significantly reduced on O. sativa than on S. anceps and E. crus-pavonis. Female RGSB laid significantly more eggs on O. sativa and E. crus-pavonis than on S. anceps. The grass species, P. maximum, P. auriculatum and S. aethiopicum did not support oviposition and development of RGSB. Adults RGSB significantly lived longer on rice than on grass species This study showed that a population of 6 RGSB on rice panicles between 3 and 9 days after panicle emergence is critical for initiation of a control action against this rice pest; and also, the destruction of the grasses species: E. crus-pavonis and S. anceps near rice fields will reduce the multiplication of S. elegans and could therefore be incorporated into its IPM component