Functional Response of Trichogramma brassicae Bez. (Hym.;Trichogrammatidae) to Different Egg Densities of Anagasta kuehniella Zell. and Plodia interpunctella Hub.

Functional response of Trichogramma brassicae Bez. to different densities of eggs of two host species Anagasta kuehniella Zell. and Plodia interpunctella Hub. was studied under laboratory conditions (24±1°C, 65±10% RH and 16: 8 L:D photoperiodism). One day old eggs of either host were offered to individual females of T.brassicae in densities 2, 4, 8, 16, 32, 64 and 128 respectively in 21, 15, 12, 9, 9, 6 and 3 replicates, for 24 hours. Logistic regression was employed to determine type of functional response and nonlinear regression to estimate parameters of searching efficiency (b) and handling time (Th).The functional response of T.brassicae to different densities of either host followed type III. Rates of searching efficiency (b) and handling time (Th) were estimated as 0.0042±0.001/h and 0.6±0.04 h for A.kuehniella, and 0.002±0.0008/h and 1.34±0.15 h for P.interpunctella respectively.