The highly seasonal hawkmoth fauna (Lepidoptera: Sphingidae) of the Caatinga of northeast Brazil: a case study in the state of Rio Grande do Norte

"The caatinga, a thorn-shrub succulent savannah, is located in Northeastern Brazil and characterized by a short and irregular rainy season and a severe dry season. Insects are only abundant during the rainy months, displaying a strong seasonal pattern. Here we present data from a yearlong Sphingidae survey undertaken in the reserve Estação Ecológica do Seridó, located in the state of Rio Grande do Norte. Hawkmoths were collected once a month during two subsequent new moon nights, between 18.00h and 05.00h, attracted with a 160-watt mercury vapor light. A total of 593 specimens belonging to 20 species and 14 genera were collected. Neogene dynaeus, Callionima grisescens, and Hyles euphorbiarum were the most abundant species, together comprising up to 82.2% of the total number of specimens collected. These frequent species are residents of the caatinga of Rio Grande do Norte. The rare Sphingidae in this study, Pseudosphinx tetrio, Isognathus australis, and Cocytius antaeus, are migratory species for the caatinga. Ninety percent of specimens and 75% of species were collected during the rainy season. With the arrival of the dry season, when bushes and trees lose their leaves and the herbaceous layer disappears, Sphingidae abundance decreases rapidly. Richness and abundance of species through the year is highly seasonal and correlated with rainfall. Erinnyis alope alope, Eumorpha fasciatus, E. vitis vitis, and Manduca brasilensis were recorded for the first time in NE-Brazil."