HOST-PLANT CONSPICUOUSNESS AND THE DISTRIBUTION OF EGGS AND LARVAE INTHE BUTTERFLY, ANTHOCHARIS-SCOLYMUS (LEPIDOPTERA, PIERIDAE)

We investigated how the distribution pattern of eggs and larval on the host plant, Turritus glabra, was influenced by the oviposition behavi or of the pierid butterfly Anthocharis scolymus. Females searched for the host plants visually and they frequently approached taller host pl ants with sparse surrounding vegetation. After encountering host plant s, oviposition behavior of females was independent of host plant chara cteristics such as height, density, and type of surrounding vegetation . A female laid eggs singly on a host plants. Most females appeared to lay their eggs regardless of the presense of eggs on the host plant. Consequently, egg and larva tended to be abundant on conspicuous host plants as measured by height or relative isolation from other plants. However, overcrowding of eggs on an individual host decreased the surv ival rate of larvae.