A study of isolating mechanisms among Neotropical butterflies of the subfamily Riodininae

Abstract

This paper examines the perching behavior of ten genera of Neotropical riodinine butterflies to detennine the nature of perching as a pre mating isolating mechanism iIi the context of the tropical forest habitat. The study shows that congeneric sympatric riodinines achieve habitat isolation through mating in different topographic sites and at different times, in addition to displays and pheromones. The study concludes that: 1) perching periods are generally of shorter duration than those of nearctic lycaenids; 2) females actively search out perching sites where they wait for males, when the latter are scarce; 3) spacing of perching sites varies considerably from one genus to the next, as do perching positions; 4) many genera, such as Nymphidium have retractable scent hairs, suggesting that pheromones are important as an ethological baIrier; and 5) observations of habitat spacing have considerable taxonomic value.