Functional response of assassin bug, Rhynocoris fuscipes (Fabrieius) (Hemiptera: Reduviidae) to cucumber leaf folder, Diaphania indicus Saunders (Lepidoptera: Pyraustidae)

摘要

The assassin bug, Rhynocoris fuscipes (Fabrieius) exhibited Holling's type II curvilinear functional response to the cucumber leaf folder, Diaphania indicus Saunders. The predator's attack rate increased as the prey density increased. The maximum predation represented by value (2.30) was found at higher prey density. But the highest attack ratio (y/x) (0.99) was obtained at 1 prey /predator density and the lowest attack ratio (0.52) at 8 prey/predator density. There was a positive correlation betweenprey density and prey killed and a negative correlation between prey density and searching time of predator at all prey densities. At high prey density, predator spent less time in searching, therefore it spent more time in handling, whereas at low preydensity the searching time was always found greater than the handling time. Handling time varied due to factors such as speed of pursuit of predator andprey escape Or prey capture SUCCeSS.