OVIPOSITION BEHAVIOR OF THE COWPEA SEED BEETLE, CALLOSOBRUCHUS-MACULATUS

The activity of female Callosobruchus maculatus (F.) (Coleoptera: Bruc hidae), the cowpea seed beetle, between making contact with a potentia l host seed and egg deposition is analysed in detail on cowpeas, mung beans and mung beans bearing conspecific eggs. The data differ from pr evious accounts in that descriptors do not ascribe function (inspectio n, patrolling, etc.) to the activities but are restricted to observabl e postures and movements. From the twenty-four discrete patterns of be haviour, kinetograms are constructed following analysis of a three-dim ensional contingency table in which expected values have been calculat ed in eight models assuming various considerations of independence, fr om complete independence of each behavioural element to alternative tw o-way interactions among the three variables, viz preceding behaviour, following behaviour, and host. Core transitions were determined by ca lculation of standardized residuals, by their high conditional probabi lities and transitional frequencies. There is a very clear sequence of oviposition behaviour, parts of which are the same on all three hosts . The simplest behavioural sequence was observed on mung beans which w as shown to be the most acceptable of the three hosts. The presence of an egg resulted in a diversification of behaviour, The method provide s a quantitative method of describing and comparing behavioural sequen ces and hence a means of determining one aspect of the acceptability o f different hosts. Using this method the occurrence of a behavioural s equence has been determined with an objective statistical basis applic able to numerous multitrophic relationships.