Possible age-dependent variation in egg-loaded host selectivity of the Pierid butterfly, Anthocharis scolymus (Lepidoptera : Pieridae): A field observation

To understand better the effects of age on host selection through conspecif ic egg detection by Anthocharis scolymus females, field observations were p erformed at a graveyard where the insect population was isolated and the ho st plant was limited to the cruciferous plant, Turritis glabra. We chased f emales and recorded their oviposition behaviors and the conditions of plant s which females approached. Older females tended to avoid ovipositing on eg g-loaded host plants and selectively laid eggs on nonloaded host plants. Th is result was not confounded by other factors such as seasonality, air temp erature, plant height, plant phenological stage, surrounding vegetation, ho st plant density, and extent of plant damage. We discuss the possibility th at females make an oviposition decision on how to lay their limited number of eggs during their remaining lifetime.