THE FUNCTIONAL RESPONSES OF ANISOPTEROMALUCS CALANDRAE (HOWARD), A PARASITOID OF CALLOSOBRUCHUS MACULATUS(F .).
K.L. HEONG
SUMMARY
The parasitoid, Anisopteromalus calandrae (Howard) was found to have Holling's Type II functional responses to the three immature stages, third instar, fourth instar and pupa, of Callosobruchus maculatus (F.). Using the nonlinear least squares technique, the parameters a' and Th of the Random Parasitoid Equation were estimated. These parameters were also estimated from the Random Predator Equation. However, the evidence obtained indicated that the searching behaviour of A. calandrae was closer to that of a true parasitoid. The searching efficiency, a', of; A. calandrae was highest tbr the fourth instar, followed by the pupae and the third instar. The handling time, Th, on the other hand, varied uniformly with the stage of the host: highest for the third instar, followed by the fourth instar and the pupa, respectively. These observations differed from those found in the true predators by other authors. Possible reasons lor these differences are discussed.
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