Differences in thermal responses in a fragmented landscape: temperature affects the sampling of diurnal, but not nocturnal fruit-feeding Lepidoptera

Abstract

Weather is the primary determinant in butterfly activity, with temperature one of the key factors affecting the biology and behavior of most Lepidoptera. Despite evidence about the influence of temperature in Lepidoptera capture patterns, few studies have analyzed microclimatic characteristics. Most studies focused on broad geographic scales and historical climatic patterns. The present study contrasts the effect of local temperature on the capture rates of two groups of fruit-feeding Lepidoptera, butterflies (diurnal) and noctuid moths (nocturnal), in a fragmented landscape. Ten fragments with five traps each were sampled in southeast Brazilian Atlantic Forest during eight days in July-2005. We found a positive relation between mean temperature and both richness and abundance of captured butterflies, but not the noctuid moths. These differences are probably a result of the miothermic nature of moths, making the moth assemblage less dependent of solar radiation than butterflies. The differences between moths and butterflies could affect the distribution of these insects across fragmented landscapes and suggest that adult moths are probably less sensitive to changes in the amount of solar radiation than adult butterflies.