Feeding potential and foraging behaviour of cheilomenes sexmaculata (F.) on cotton whitefly, Bemisia tabaci (Gennadius).

Feeding potential and foraging behavior are complimentary to determine the efficiency of a predator. The predatory potential of both grub and adult stages of Cheilomenes sexmaculata (F.) (Coleoptera: Coccinellidae) was investigated against different developmental stages of cotton whitefly, Bemisia tabaci Gennadius (Aleyrodidae: Hemiptera), under laboratory conditions (27 ± 2 °C; 70 ± 5% RH; 14 h L: 10 h D). Fourth instar grub of C. sexmaculata exhibited the highest feeding potential against the whitefly stages (41.74 adults, 33.41 pupae and 31.33 nymphs), whereas first instar grub exhibited the lowest feeding potential (10.15 adults, 9.15 pupae and 7.00 whitefly nymphs). The female beetle consumed the highest number of prey (1445.29 adults, 1364.88 pupae, and 1374.35 whitefly nymphs) followed by male beetle (1390.12 adults, 1308.18 pupae and 1325.35 whitefly nymphs). Both Roger's and Holling's models indicated a type II functional response curve for all the grub and adult stages of C. sexmaculata. Cheilomenes sexmaculata female showed the highest attack rate (4.65 h^-1), and the maximum rate of predation 37.5 insects/day, whereas the male beetle recorded the lowest handling time (0.02 h). The fourth instar grub showed the highest attack rate (1.30 h^-1) against the B. tabaci pupae, whereas the female beetle showed the maximum rate of predation 38.18 insects/day, with the lowest handling time (0.04 h). Female beetle showed the highest attack rate (6.87 h^-1), whereas the fourth instar grub showed the maximum rate of predation 41.7 insects/day with the lowest handling time (0.01 h). Hence, it is advocated to release the fourth instar grubs and adult females of C. sexmaculata collectively for the augmentative biological control of B. tabaci in the IPM program. [ABSTRACT FROM AUTHOR]