The Hepialidae constitute 82 genera contain at least 700 currently recognised species of these moths worldwide. The family Hepialidae is considered to be very primitive, with a number of structural differences to other moths including very short antennae and the lack of a functional Proboscis or frenulum. The moths are homoneurous with similar forewings and hindwings. Many species display strong sexual dimorphism, with males smaller but more boldly marked than females.
Hepialidae are distributed on ancient landmasses worldwide except Antarctica, but with the surprising exceptions of Madagascar, the Caribbean islands and in Africa, tropical West Africa. In the Oriental and Neotropical regions, hepialids have diversified in rainforest environments, but this is not apparent in the Afrotropics. Hepialids mostly have low dispersive powers and do not occur on oceanic islands with the exception of Phassodes on Fiji and Western Samoa, as well as a few species in Japan and Kurile Island.
Swift moths are usually crepuscular and some species form leks. In most genera, males fly to virgin females that “call” with scent. In other genera, virgin females “assemble” upwind to displaying males, which emit a pheromone from scales on the metathoracictibae. In such cases of sex role reversal, there may also be visual cues also. Sometimes they hover singly as if suspended from a thread or flying in a figure of eight motion.
Source: Wikipedia
(Sumaco, Ecuador)