Habitat Impact on Ultraviolet Reflectance in Moths

Abstract

A comparison of 95 species of Central European moths, representing 11 families and inhabiting various habitats, was carried out in order to detect the potential impact of biotope on the ultraviolet (UV) light reflectance of their wings. Based on digitized photographs taken under UV light conditions, a phylogeny-controlled redundancy analysis relating UV reflectance to preferred habitat type (xerophilous, mesophilous, and hygrophilous) and habitat openness (open, semiopen, and closed) was carried out. Species preferring hygrophilous habitats displayed significantly higher UV wing reflectance than species inhabiting xerothermic and mesic habitats, and this pattern remained significant even after controlling for phyletic relationships. In contrast, UV wing reflectance displayed no pattern related to habitat openness. Given the higher UV reflectance of water and humid surfaces, we interpret these results, which are based on the first comprehensive sampling of UV reflectance in Central European moths, in terms of predator avoidance under habitat-specific light conditions. We conclude that the moisture content of the environment may markedly contribute to the variation of appearance of moth wings for better imitation habitat characteristics and therefore to increase protection.

Keywords: Lepidoptera; mimicry; phylogeny; ultraviolet reflectance.