Frazer, B.D.

The eggs of seven species of locally occurring coccinellids were reared at constant temperatures. The survival of eggs to hatching, rate, and thermal requirements for hatching were determined. The results were used to evaluate the importance of thermal adaptation of coccinellids in selecting them as biological control agents and in determining the relative species composition of locally occurring faunas of coccinellids.

Behaviour of locally occurring adult females of seven species of coccinellids was assessed on wooden dowel and paper models that mimicked branching patterns and arrangements of leaf attachments to stems. Ambient temperature and hunger of the beetles were controlled. The movements up or down the main branch of the branch models when contacted from a side branch, duration of searching, and method of leaving leaf models were recorded for 20 beetles of each species.Each species responded to the seven models with different frequencies of behaviours that reflected species-specific modifications of the taxes that lead coccinellids to the tops and terminal parts of plants. Some beetles consistently modified the pattern of responses on die models that was displayed by die species as a whole. The individual modifications could be selected for. The differences in frequencies of behaviours were judged to be sufficient to result in differences in the efficiency with which plants with different architectures were searched.