Impact of azadirachtin on the haemodynamics of Cyrtacanthacris tatarica L. (Acrididae: Orthoptera)

Abstract

Haemocoelic injection of azadirachtin (2, 4 and 6 μl/g body weight of the test insect) into the final instar female nymphs of Cyrtacanthacris tatarica L. increased the haemolymph volume significantly than the ethanol-injected individuals. Total haemocyte count (THC), computed from four recorded haemocytes (prohaemocytes, spherulocytes, granulocytes and plasmatocytes) decreased with increasing concentration of azadirachtin and the overall reduction ranged from 31 to 41%. A dose-dependent inverse relationship was obtained between the haemolymph volume and total haemocyte number. Bulging of cytoplasm, membrane breakdown and release of cytoplasmic materials were recorded in plasmotocytes, while granulocytes showed vacuoles in the cytoplasm and nucleus. However, no such deformities were observed in prohaemocytes and spherulocytes.