Thermal response of two sexually dimorphic (Odonata) over an ambient temperature range.

Organisms may internally or behaviorally regulate their body temperatures or conform to the ambient air temperatures. Previous evidence is mixed on whether wing pigmentation influences thermoregulation in various odonates.We investigated the thermal response of sympatric North American and with a thermal imaging study across a 25°C ambient temperature range.We found that regressions of thorax temperature on ambient temperature standardized by species had similar slopes for male and female , but females were consistently 1.5°C warmer than males. In contrast, the sexes of differed in slope, with females having a slope less than 1.0 and males having a slope greater than 1.0.We found that regressions of thorax temperature on ambient temperature standardized by sex had similar slopes for males and females of both species, but females were consistently 2.1°C warmer than females.Given that is strongly sexually dimorphic in pigment, but is not, our findings suggest that wing pigmentation may influence thermal response rate in sympatric populations of both species.