Functional Response of Stethorus gilvifrons Mulsant (Coleoptera: Coccinellidae) to Different Developmental Stages of Eutetranychus orientalis Klein

Functional response of Stethorus gilvifrons Mulsant to varying densities of different developmental stages of Eutetranychus orientalis Klein was examined in a simplified castor bean leaf disc arena under the laboratory condition. One S. gilvifrons female was isolated individually for 24h with different prey densities (4،8،12،24،48،96،120) at 300C and photoperiod of 14:10 (L: D) h. The number of prey consumed by the predator was checked after 24 h. S. gilvifrons showed a type II functional response to all different developmental stages of E. orientalis. Based on the random predator equation، estimated attack rates of S. gilvifrons after 24h were 0. 0464،0. 0442 0. 0450، 0. 0484 and 0. 0480، and estimated handling times to eggs، larvae، nymphs، adult females and adult males were 0. 082، 0. 060، 0. 066، 0. 045 and 0. 076، respectively.