Predating Response Of Chrysoperla Zastrowi Sillemi (Esben-Peterson) On Raya Aphid Lipaphis erysimi (Keltenbach)

Abstract

The control of insect pests through biological means relies on the ability of natural enemies to prey on pests. This ability, known as the functional response. It plays a crucial role in selecting the appropriate species for biological control programs. In this particular study, the researchers aimed to evaluate the functional response of the third instar grub of C. zastrowi sillemi, a species of lacewing belonging to the family Chrysopidae, towards the aphid Lipaphis erysimi, which infests Raya plants (Brassica juncea). To achieve this, five different densities of aphids were used as Predator: prey ratio (1:50, 1:100, 1:150, 1:200, and 1:250). The results of the study indicated a type II functional curve response, as determined by logistic regression analysis, of C. zastrowi sillemi towards L. erysimi. The Hollings Type II functional response implies that the rate at which the predator consumes its prey increases with increasing prey density, but eventually reaches a plateau despite further increases in prey density. The aphids' consumption, search rate (a`), and maximum predation rate (1/Th) were observed to be lower (19.68, 0.97, and 0.55) in comparison to when grubs were fed on an artificial diet, where they were higher (20.16, 0.20, and 0.59). Nonetheless, the duration required by third instar grubs to handle prey was longer (2.58) when on a natural diet but shorter (2.42) when on an artificial diet.