Padrão de melanismo em borboletas neotropicais

Abstract

Patterns of brightness and coloration of butterfly wings may have intraspecific, interspecific and physiological roles, with one of the main functions being thermoregulation. Differences in brightness between the ventral and dorsal surfaces serve to capture and dissipate heat, as butterflies regulate exposure to heat sources by opening and closing wings. Melanism can vary among butterfly families, different wing faces, and be related to wing size and environmental factors. Although well-established patterns exist for other biogeographic regions, no studies have evaluated these issues for Neotropical butterflies. The two main objectives of this work were (1) to survey the scientific production on butterfly color patterns on a global scale, to identify the main knowledge and geographic research gaps; and (2) to evaluate which environmental factors, wing size and taxonomic families are related to neotropical butterfly wing melanism. The production of papers on butterfly coloration increased and followed the overall scientific production rate (r = 0.076, p = 0.25). We note the concentration of published articles in English-speaking countries (~60%), with most studies having American first authors (27.8%). We found that smaller butterflies are lighter (p < 0.05) and that families vary in brightness differences between the dorsal and ventral faces. There was no relationship between environmental variables and brightness pattern for Neotropical butterflies (p > 0.05), and butterflies from different biomes show similar melanism patterns. Probably, other variables may influence the melanism pattern of these butterflies, such as solar irradiance. For warmer environments, it is advantageous for the butterfly to be small and bright, thus avoiding stresses due to overheating. This variation in brightness among families may be related to different thermal tolerance thresholds, as well as different anti-predatory strategies such as "dynamic flash". Nevertheless, it is necessary to include more species from other biomes and localities in the rest of the country to re-evaluate our hypotheses based on more extensive environmental gradients, given that much of the research focusing on coloration and brightness patterns of butterflies evaluates communities from the northern hemisphere.