Searching preference of the parasitoid,Anisopteromalus calandrae (Howard) for different stages of the host,Callosobruchus maculatus (F.) in the laboratory

Summary The functional response parameters of the parasitoid,Anisopteromalus calandrae (Howard) to the third instar, the fourth instar and the pupae ofCallosobruchus maculatus (F.) were estimated from the Random Parasitoid Equation. By modifying this equation for a two host situation and using the parameters estimated above, a no switch model could be obtained. This model was then used to test for switching. In the preference experiments where two stages of the host were presented to the female parasitoid, a definite preference for the fourth instar followed by the pupa and the third instar, respectively was shown. There was, however, no evidence of switching. There was also no evidence that the data fitted the no switch models which suggests that when the parasitoid is searching in an environment with two or more hosts, its searching behaviour is more complex.