OVIPOSITION MISTAKES IN HERBIVOROUS INSECTS - CONFUSION OR A STEP TOWARDS A NEW HOST GIANT

Insects sometimes lay eggs on host plants unsuitable for their offspri ng. One explanation for this behavior has been that the association of insect and plant is new, and therefore, the insect has not had time t o develop a capacity for discrimination. We explore an alternative exp lanation using a simulation model of gall-forming cecidomyiid oviposit ion behavior. It is demonstrated that insects which can discriminate b etween plant types have little advantage over 'confused' (non-discrimi nating) counterparts when the proportion of poor host plants is large and the time available for oviposition is short. When non-discriminati ng females also oviposit on their eclosion plant the advantage of disc rimination is negligible. We suggest that for insects where a host shi ft is costly, e.g. gall-forming cecidomyiids with an intimate relation ship with the plant, there are only small penalties to retaining a non -discriminating oviposition strategy. Insect traits such as short adul t life span and poor capacity for directed flight further act to maint ain the insect in a state of perpetual 'confusion'.