Genus Hydrosmecta C. G. Thomson: a review of species occurring in eastern Canada (Coleoptera, Staphylinidae, Aleocharinae) Author Klimaszewski, Jan Author Webster, Reginald P. Author Davies, Anthony text Insecta Mundi 2017 2017-12-29 2017 593 1 17 journal article 10.5281/zenodo.5169545 1942-1354 5169545 843C58D8-84D7-4BAA-94C8-466B133685AF Hydrosmecta pseudodiosica Lohse ( Fig. 39–47 ) Hydrosmecta pseudodiosica Lohse , in Lohse et al. 1990: 149 . Majka and Klimaszewski 2008 ; Webster et al. 2012 . Diagnosis. Body length 2.5–2.7 mm ; body brown to piceous, dull, elytra and legs dark brown ( Fig. 39 ); microsculpture of forebody minute, consisting of rounded meshes; head subquadrate, at eye level about as wide as at level of tempora; eyes about as long as postocular region in dorsal view; antennae slender, antennomeres II and III subequal in length, following ones elongate but decreasing in length toward apex; glossa thin and long, Y-shaped, deeply split apically; each mandible with subapical tooth; pronotum transverse, 1.25 as broad as long and 1/6 broader than head, broadest near apex, sides converging basally to obtuse posterior angles; elytra at suture 1.3 as long as pronotum along midline of disc, about 1.2 as broad as pronotum; abdomen subparallel, tergites becoming longer toward apex. Male: tergite VIII broadly arcuate ( Fig. 42 ); sternite VIII with apical margin straight medially, very broadly rounded laterally ( Fig. 43 ); median lobe of aedeagus with narrowly oval bulbus, evenly coalescent with short triangular tubus in dorsal view ( Fig. 41 ); in lateral view tubus with apical part narrow, directed slightly ventrad ( Fig. 40 ); internal sac with two elongate structures in bulbus ( Fig. 41 ). Female: tergite VIII truncate apically ( Fig. 44 ); sternite VIII with apical margin moderately produced, with moderately deep, rounded emargination at middle ( Fig. 45 ); spermatheca with capsule small, spherical, with shallow and moderately wide apical invagination, stem long, irregularly twisted and swollen posteriorly ( Fig. 46, 47 ). This species is similar to H. odiosica Casey from California , but has a larger and longer body ( H. odiosica is 1.8 mm long) and a more transverse pronotum. Distribution. Origin: Nearctic. Canada : NB, ON, YT . USA : not recorded. Collection and habitat data. Habitat: riparian habitats, sandy and cobblestone shores of brooks and rivers; adults under small cobblestones and gravel set in sand on a partially shaded cobblestone bar near the outflow of a brook into a clear rocky river. Collecting period: V, VI. Collecting method: hand collecting or aspirating specimens from near and under cobblestones at edges of streams.