Functional response estimations of Chrysoperla carnea to different densities of Aphis craccivora and Gynaikothrips ficorum nymphs

Estimativas da resposta funcional de Chrysoperla carnea em diferentes densidades de ninfas de Aphis craccivora e Gynaikothrips ficorum

Abstract

The functional responses of Chrysoperla carnea larvae were evaluated at different seven densities of the 3^rd instar nymphs of Aphis craccivora and Gynaikothrips ficorum in order to find out the relationship between predator densities and its prey by the, and also to find out their capability for biological control of aphids and thrips. Results revealed that all tested larval instars of Ch. carnea exhibited a type II response in relation to the prey. Moreover, the coefficients of attack rate (a) and handling time (T_h) was differed among various growing instars of predator and for the prey species. The 3^rd instar larvae of Ch. carnea manifested the highest attacking rate (1.23 and 1.22) on the 3^rd instar nymphs of A. craccivora and G. ficorum, respectively. In addition it exhibited the highest maximum predation (Na _max) (50.00 and 52.63) on A. craccivora and G. ficorum nymphs, respectively as compared with the other treatments. Accordingly, Ch. carnea could be considered as a promising bio-control agent for A. craccivora and G. ficorum management.

Keywords:
Chrysoperla carnea; functional response; aphids; thrips; predation rate; biological control