Phenotypic plasticity has been described for morphological and life-history traits in many organisms. In Drosophila, temperature drives phenotypic change in several traits, but few neotropical species have been studied and whether the phenotypic variation associated with plasticity is adaptive remains unclear. Here, we studied the phenotypic response to temperature variation in the distant related neotropical species Drosophila mercatorum (Patterson and Wheeler, 1942) and Drosophila willistoni (Sturtevant, 1916). We evaluate if wing shape variation follows that observed in the neotropical species Drosophila cardini (Sturtevant, 1916): round wings at lower temperatures and narrower wings at higher temperatures. The variation in egg-adult development time and wing size, shape, and allometry was described using reaction norms and geometric morphometrics. In both species, development time and wing size decreased with increasing temperature and wing allometry showed that size explained ≈10% of the shape variation. Wing shape, however, exhibited contrasting responses. At higher temperatures, D. mercatorum developed slightly slender wings, following the pattern previously found for D. cardini, while D. willistoni developed plumper and shorter wings, supporting previous studies on Drosophila melanogaster (Meigen, 1830). We conclude that all traits studied here were influenced by temperature, and that wing shape seems also to be influenced by phylogeny.
Clinal variation and laboratory adaptation in the rainforest species Drosophila birchii for stress resistance, wing size, wing shape and development time
