Abstract: The functional response of Cotesia plutellae to the increase of larval density of diamondback moth(Plutella xylostella) was examined at indoor temperatures 15℃,20℃,25℃,30℃ and 32.5℃. The results showed that the functional response could be described very well by Holling's disc equation at all test temperatures, but the parameters of the functional response differed significantly. The rates of successful attack at 25℃, 30℃ and 32.5℃ were significantly higher than those at 15℃ and 20℃, and the handling time decreased with increase temperature. After exposed to various densities of DBM 3rd instar larvae for 5 hrs, some females failed to produce eggs to parasitize any larva. The percentage of females which have parasitized at least one DBM larva increased with the increases of both temperature and host density.

Key words: Cotesia plutellae, Plutella xylostella, Functional response, Temperature effect, drought, shading, Camellia japonica (Naidong), gas exchange.