The parasitical efficiency of Cotesia plutellae Kurdjumov were studied under the experimental condition of (27±1)℃ and (75±5)% RH.The functional response of Cotesia plutellae Kurdjumov to the third instar larvae of the diamondback moth, Plutella xylostella L. can be fitted with Holling′s type Ⅱ, which was described by Holling disc equation Na=0.9295N/(1+0.0918N); the mutual interference among parasite individuals could be simulated by HassellVarley′s model a=0.1435P0.4987.Based on the abo...