Three new species of Flint microcaddisflies from Peru (Insecta: Trichoptera) including DNA-based larval associations.

In this paper, we have described and illustrated three new species of from Peru: , , and Larvae of the latter two were also associated to male specimens based on comparison of a fragment of COI gene and pharate male identification. and share a unique feature: a semi-dome process formed by a thickened area on male forewings. The three species can be easily identified by wing coloration and male genitalia. Furthermore, can be recognized by its sternum VIII with a median digitate process on posterior margin, slightly capitate; and by long dorsolateral processes from segment VIII, which cross each other apically in dorsal view. can be distinguished by sternum VIII bearing a pair of short, posterior, spinelike processes, which are curved inwards and bordered by a rounded, membranous structure, and by a pair of short, heavily sclerotized, dorsolateral processes. can be distinguished by strong spine-like processes arising dorsally from subgenital plate and by sternum VIII with posterior margin divided into two plate-like lobes. Larvae of and are similar to other larvae known. They can be distinguished from each other by the shape of the operculum formed by terga VIII and IX, and number of setae on the second abdominal pleurite. Maximum likelihood analyses of 20 COI sequences, including nine species, placed and as sister species and related to a clade including , , and , while was found as sister to . Despite the close phylogenetic relationship found between and , they are separated by 14.9% minimum K2P divergence of COI. The highest intraspecific distance observed was 1.4% for individuals. Although the Peruvian caddisfly fauna has around 320 known species and almost a third of them are microcaddisflies, in this paper we present the first descriptions of species for the country.