author(s)
PJ Edward George, B Ravichandran, A Jesudurai and Dunston P Ambrose

abstract
Relative toxicity of two commonly used insecticides namely cypermethrin (Cymbush 10 EC) and fenvalerate (Sumicidin 20 EC) to the non - target reduviid predator Rhynocoris marginatus was evaluated. Among the two insecticides tested, fenvalerate was more toxic than cypermethrin. Both cypermethrin and fenvalerate increased the number of prohaemocytes and granular haemocytes and decreased the plasmatocytes. They also caused changes in the density of cystocytes and oenocytoids. Though both the insecticides increased the total haemocyte counts, highest impact was caused by fenvalerate.