Taxonomic revision of the sexually dimorphic flies of the Neotropical genus Euepalpus Townsend, 1908 (Diptera: Tachinidae), with notes on sexual patches in Tachinini

Euepalpus Townsend, 1908 is a small Neotropical genus of bristle flies (Diptera: Tachinidae: Tachinini), which includes two valid species whose taxonomy is unclear, mainly because males and females are sexually dimorphic. Males exhibit a pair of sexual patches on the dorsal surface of abdominal tergite 5, an unusual feature in Tachinidae. Here, the genus is revised, including a key to species and detailed descriptions and illustrations of the type material and males and females of each species. The male and female terminalia of Euepalpus species are described for the first time. Finally, I discuss the occurrence and distribution of sexual patches in Tachinini.