First Records of the Microcaddisfly Genus Metrichia Ross, 1938 (Trichoptera: Hydroptilidae) in Brazilian Amazonia: Three Remarkable New Species and a Checklist from Brazil

Abstract

Abstract. The microcaddisfly genus Metrichia Ross is the second most species-rich within Ochrotrichiinae, comprising 141 species distributed mainly in the Central America. Recently, a large number of Metrichia species have been described for the Brazilian fauna; however, these species only are known from the Atlantic Forest, Caatinga, and Cerrado biomes. Aiming to fill these gaps, three new species of Metrichia are described and illustrated based on males collected in three protected and preserved areas of Brazilian Amazonia: Floresta Nacional do Tapajós, Parque Nacional Serra do Divisor and Parque Nacional Serra da Mocidade. Metrichia divisor sp. nov., Metrichia flinti sp. nov. and Metrichia myriachaeta sp. nov., can be recognized mainly by the type and position of setae on the preanal appendage and inferior appendage and by the morphology of the dorsolateral hook and phallic apparatus. Metrichia flinti sp. nov. is clearly a member of the M. aberrans Group based on the absence of pouches in abdominal segments and phallus with two spines subapically. However, neither M. divisor sp. nov. nor M. myriachaeta sp. nov. fits clearly in any of the current species groups in Metrichia, and hence they are not assigned to any of these species groups in this study. Finally, we provide a checklist of the Metrichia species from Brazil.