Effect of temperature and search area on the functional response of Anisops sardea (Hemiptera: Notonectidae) against Anopheles stephensi in laboratory bioassay

Present study was carried out to establish the influence of abiotic factors on foraging activities of a predatory hemipteran insect Anisops sardea against Anopheles stephensi larvae. The functional response of A. sardea was evaluated in variable density of prey items with variation in search area (100, 250, 500 and 1000 ml water volume) and temperatures (20, 25 and 30 °C). The results of laboratory bioassay revealed that prey consumption rate of predator species was positively related with increasing temperature and inversely related with increasing search area. Polynomial logistic regression equations and associated parameters showed that A. sardea exhibited a type II functional response in variable search area and type-III response at variable temperatures. Related response specific attack rates and handling times were also evaluated in presence of specific abiotic factors.