Review of the genus Hyrtanella (Ephemeroptera: Ephemerellidae)

Abstract

The genus Hyrtanella Allen and Edmunds (Ephemeroptera: Ephemerellidae) is distinguished from other Ephemerellinae by larvae that have fully operculate gills and single median spines on the posterior margins of abdominal terga 8 and 9. Eggs have one polar cap and a smooth chorion. Male adults are not known, and female alates cannot be assigned to species, based on present data. The genus probably is endemic to the island of Borneo, and it contains two species: H. christineae and H. pascalae, new species. Hyrtanella pascalae is described based on eggs, larvae, and one male subimago. The larva of H. pascalae is distinguished from H. christineae by its smaller size, blunt genal projections, and smooth forefemora. The male subimago has genital forceps segment 3 elongate.KEY WORDS: Hyrtanella, Ephemeroptera, Ephemerellidae, Ephemerellinae, Hyrtanella christineae, Hyrtanella pascalae, new species, descriptions, Borneo, misidentificationsThe genus Hyrtanella Allen and Edmunds (Ephemeroptera: Ephemerellidae) was described for some distinctive larvae and female adults from the island of Borneo (Allen & Edmunds 1976). The monospecific genus (type species: H. christineae Allen and Edmunds) has been classified in the monogeneric tribe Hyrtanellini (Allen 1980; Allen 1984) of the subfamily Ephemerellinae (McCafferty & Wang 2000). Landa et al. (1982) and Landa and Sold n (1985) provided details about the internal anatomy of Hyrtanella. Edmunds and Polhemus (1990) reported the genus from the Malay Peninsula, northern Thailand, and southern India, but these records probably are based on misidentifications.