Predation by Orius sauteri (Poppius) (Heteroptera : Anthocoridae) on Thrips palmi Karny (Thysanoptera : Thripidae): Functional response and selectivepredation

Functional responses of different stages of Grills sauteri to densities of Thrips palmi were studied. Most stages of O. sauteri exhibited Holling's Ty pe-II response. The number of T. palmi consumed by O. sauteri nymphs increa sed with the stage of O. sauteri, however late fifth stage O. sauteri nymph s consumed a much smaller number of T. palmi larvae than early fifth stage nymphs. O. sauteri adult females consumed a slightly smaller number of T. p almi larvae than early fifth stage nymphs. O. sauteri adult males consumed a smaller number of T. palmi larvae than adult females. O. sauteri nymphs k illed more T. palmi larvae than T. palmi adults. However, there was no mark ed difference between the two stages of T. palmi killed by O. sauteri adult females. The number of T. palmi consumed by O. sauteri adult females incre ased with increasing temperature. Selective predation experiments on O. sau teri on different stages of T. palmi revealed that the preference for T. pa lmi adults and larvae changed with the development of O. sauteri.