Oviposition behaviour of post-diapause Hypolimnas bolina (L.) (Lepidoptera : Nymphalidae) in tropical Australia

Observations were made on the oviposition behaviour of post-diapause adults of Hypolimnas bolina (L.) at a site in Townsville, Australia (19°15'S, 146°45'E). Females most often laid one or two eggs on freshly emerged seedlings (<10 min height) of Synedrella nodiflora (L.) (Asteraceae). Mature foodplants of S. nodiflora, Sida rhombifolia (L.), Sida acuta (Burm. f.) and Malvastrum coromandelianum (L.) (all Malvaceae) were present, and occasionally sampled by females, but were ignored as oviposition substrates. Females were present at the site from 0900 to 1500 hours, and were more persistent than their male counterparts under adverse environmental conditions (i.e. reduced temperature and solar radiation). The relatively high number and apparent selectiveness of ovipositing females in this situation indicates the importance placed on utilising fresh growth of the larval foodplant. This behaviour may serve to maximise the rate of return per unit reproductive effort of post-diapause females.