FORAGING BEHAVIOR OF LADYBIRD LARVAE (COLEOPTERA, COCCINELLIDAE)

Coccinellids, particularly their larvae are very voracious. Their fora ging behaviour has been extensively studied in an attempt to determine their potential for controlling pest aphids, which occur in patches t hat are relatively short lived and within which the aphids are not uni formly distributed but clumped. In seeking aphid prey ladybirds like o ther insect predators forage both extensively and intensively, and use visual and olfactory cues for orientation. Intensive search follows a n encounter with an aphid and serves to keep the predator in the vicin ity of a cluster of prey. The success of larvae in capturing prey is d ependent on abiotic and biotic factors such as plant structure, specie s of aphid attacked, the predator, in particular its age, level of hun ger and genetic characteristics, and intra- and interspecific competit ion. It is suggested that the poor progress in developing a foraging t heory for insect predators, and ladybirds in particular, is a conseque nce of having mainly concentrated on the foraging behaviour of the mos t voracious stage, the larva. The behaviour of larvae serves to keep t hem within the patch selected by the adult. Thus for a better understa nding we need information on the cues used by ladybird adults to asses s the quality of patches of prey.