Local host plant abundance explains negative association between larval performance and female oviposition preference in a butterfly

Abstract

Widely distributed polyphagous insects provide opportunities to understand the influence of local plant communities on geographical variation in patterns of host plant use. Larval performance in the widespread butterfly Acraea terpsicore appears to vary geographically. This prompted us to investigate in detail the host plant-associated divergences in behaviour and life-history traits between two Indian populations of this species. Given that the two populations differ in abundances of the host plants, we tested whether local availability of host plants has influenced the evolution of larval performance and female oviposition preference. We also investigated whether females prefer to oviposit on host plants that are optimal for larval development. We found that host plants influence larval performance in a similar manner for both populations. Female preference is not correlated with larval performance; however, the preference varied between the populations. In one population, the females preferred a locally abundant host plant for oviposition although the plant was suboptimal for larval development. The negative correlation between preference and performance correlation suggests that the high cost of searching for the optimal host plant has influenced female preference.