Despite the fact that butterflies are considered well collected and studied, there has been little research on the subfamily Satyrinae (Lepidoptera: Nymphalidae). One of the most diverse satyrine groups is the neotropical subtribe Euptychiina. There are 43 euptychiine genera and more than 300 species. Characters from larval morphology and DNA sequence data were used in phylogenetic analyses of the genera. There was support from these analyses that Euptychiina is not a monophyletic group and that there are three major clades in the subtribe. Ancestral reconstructions of several life history characters showed strongly congruent and interesting patterns. Both specialized feeding habit (confined to a genus) and generalized feeding habit were found within Euptychiina. These habits were not distributed randomly on the tree, but were found in discreet clades, with specialization occurring in those taxa utilizing non-grass host plants, such as sedge or bamboo. One unusual feature of euptychiines is that some species complete their development in four instars and others in five. These two developmental strategies were also not randomly distributed on the cladogram, but were highly associated with specialization. The ancestral clades contained specialized feeders with four instars, derived clades contained generalized feeders with five instars. Further support come from a complementary reversal within the derived clade back to specialization and four instars. This work has highlighted an interesting association, but the biological and physiological interactions between these two traits are not known. There is little published work addressing the evolutionary costs or genetic controls of each instar nor the effects of host use on instar number. A proposed hypothesis, not tested in this research, is that the high silica content in some grasses exerted selection pressure towards five instars in order to renew worn mandibles.
Species 1: Lepidoptera Nymphalidae
Keywords: Satyrinae, specialization
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA