Studies on the predatory behavior of the mimetic bug phonoctonus fasciatus beauvois (hemiptera: reduviidae)

The predatory behaviour of phonoctonus fasciatus beauvois {Hemiptera: Reduviidae) was studied with a view to assessing its possible role in regulating the populations of dysdercus spp. It was originally thought that, phonoctonus would be more closely associated with and feed on the pyrrhocorid species that it mimics than with any others {Stride, 1956). But it has been found that, P. fasciatus is a generalist predator and seem not to discriminate among its prey on the basis of mimetic resemblance. Polyphagous feeding habits limits its ability to control dysdercus populations except on small populati ions found on localized, isolated wild tree hosts. The effect of prey species on development period of the predator, P. fasciatus was studied. All prey species tested were capable of sustaining basic levels of development and survival of the predator. However, the mean duration of total development of P. fasciatus was found to vary with prey species. Whereas feeding on roscius elongates and dysdercus nigrotasciatus increased total development period of the predator i.e. 67.2 and 66.8 days respectively, the development period was shorter on dysdercus fasciatus 61 days than when fed on dysdercus nigrofasclatus 64.3 days. P. fasciatus exhibited a type II functional response i.e. predation efficiency decrease when the prey population exceeds a certain density. Its implication in biological control is discussed.