Temperature, Development and Survival in Monophagous and Polyphagous Tropical Pierid Butterflies

Abstract

Development rates and juvenile survival of seven species of pierid butterfly from the Australian tropics were examined in laboratory conditions at a range of temperatures between 15 and 32°C. We studied three monophagous species, Eurema brigitta, E. laeta and E. herla, and four oligophagous or poly- phagous species, E. hecabe, E, smilax, Catopsilia pomona and Pieris (Artogeia) rapae; the last of these is the predominantly temperate cabbage butterfly, which has established a small tropical population on the Atherton Tableland in north Queensland. Larval and pupal stages of all species survived poorly at temperatures above 30°C, and most showed reduced survival below 22°C. Within their optimal temperature ranges, smaller species tended to survive better than larger ones. Oligophagous and polyphagous species developed more rapidly than monophagous ones, even though three of the former are larger than the latter. Development thresholds were between 10°C (for P. rapae) and 15°C (for C. pomona). There was little correlation between development threshold and latitudinal distribution, and we suggest that selection for the ability to develop relatively rapidly at lower temperatures may be influenced by the seasonal timing of the breeding season as well as by geographic distribution.