| The genus Neotrichia Morton (Trichoptera: Hydroptilidae) is one of the most diverse groups of microcaddisflies. New Neotrichia species continue to be discovered and, as diversity within the taxon continues to expand, intrageneric and intergeneric relationships have become unclear. A revision of the defining characters of the genus Neotrichia is the necessary foundation for continued study of this diverse taxon.; This work was designed to revise the genus Neotrichia based on type specimen comparisons. The syntype series for the type species, Neotrichia collata Morton, was examined. Seven morphological characters, confirmed or identified during this examination, were also present in all other Neotrichia species examined. It is this suite of characters, as follows, that constitutes the revised definition of the genus Neotrichia: (1) 0,2,3 tibial spur formula, (2) antennae with 18–19 segments, (3) three ocelli, (4) triangular mesoscutellum, (5) triangular metascutellum, (6) wing venation reduced; veins in hindwing converging to a closed, wingtip loop, and (7) phallus with paramere.; The type specimens for 64 Neotrichia species were examined and, as a result of these examinations, thirteen new species are described. Interspecific variation was found in abdominal segments VIII–X, including post-abdominal, male genitalia. Variation among the following characters was found to be diagnostic at the species level: (1) presence/absence of dorsal, setal lobes on segment VIII, (2) presence/absence of dorsal, setal lobes on segment IX, (3) apicolateral extension of segment IX, (4) apical structure of segment X, (5) subgenital plate structure, (6) inferior appendage structure, (7) bracteole structure, (8) phallus paramere structure, and (9) phallus apex structure.; As an outcome of the interspecific comparisons, six species groups were identified and are described herein. Relationships among these six species groups were established using a cladistic analysis of the above morphological characters. The search produced one most parsimonious tree with a tree length of 15.; The type species for the other genera of the tribe Neotrichiini, Mayatrichia Mosely, Taraxatrichia Flint and Harris, and Kumanskiella Harris and Flint, were also examined during the evaluation of the genus Neotrichia. As an outcome of these examinations, a new genus, Harrisella, is described. This monotypic genus is established for the species, Harrisella yagua (Harris), which was originally described as a Neotrichia species. The following suite of seven characters defines the new genus Harrisella: (1) 0,2,3 tibial spur formula, (2) antennae with 31 segments, (3) three ocelli, (4) mesoscutellum triangular (5) metascutellum trapezoidal, (6) forewing with sclerotized, transverse band, and (7) phallus simple, lacking paramere.; Relationships among the genera of the tribe Neotrichiini were established using a cladistic analysis of the above morphological characters. This analysis was considered preliminary because females of the new genus Harrisella and the larvae of both Harrisella and Taraxatrichia are unknown. The results were consistent with those of prior analyses, and the new genus Harrisella appears to show a close relationship with the genus Mayatrichia. |
