A comparative study on insect longevity: tropical moths do not differ from their temperate relatives

Comparative studies on insects can significantly contribute to understanding the evolution of lifespan, as the trait can feasibly be measured in a high number of species. If the evolutionary determinants of longevity were mainly extrinsic (ecological), related species from different habitats should systematically differ in individual lifespans. We recorded adult longevities for 110 species of geometrid moths from a tropical community and paralleled the lifespans in this tropical assemblage with a temperate counterpart. Comparative analyses using an original phylogenetic reconstruction revealed that in the studied tropical assemblage, larger moth species tended to live longer, and that females had slightly shorter lifespans than males. Average adult lifespans in tropical geometrids, and the relationships of lifespan with other variables, were found to be highly similar to those reported for their temperate region relatives. The among-region similarity leads to the conclusion that intrinsic (physiological) determinants of longevity dominate over extrinsic (ecological) ones: the contrasting environments of tropical and temperate forests have hardly produced differences in moth longevities.