Hydrosmecta borealis Klimaszewski and Langor

Klimaszewski, Jan, Webster, Reginald P. & Davies, Anthony, 2017, Genus Hydrosmecta C. G. Thomson: a review of species occurring in eastern Canada (Coleoptera, Staphylinidae, Aleocharinae), Insecta Mundi 2017 (593), pp. 1-17 : 4-5

Hydrosmecta borealis Klimaszewski and Langor

( Fig. 1–8 )

Hydrosmecta borealis Klimaszewski and Langor , in Klimaszewski et al. 2011: 162.

Diagnosis. Body length 2.3–2.5 mm; subparallel, flattened, light brown to dark brown with antennae, legs and elytra slightly paler and reddish brown; moderately glossy, with fine, moderately dense punc- tation and faint meshed microsculpture on forebody ( Fig. 1 ); head as wide as pronotum, with large and protruding eyes; antennae moderately robust, antennomere IV subquadrate and V-X slightly elongate; pronotum widest at middle, as wide as head and abdomen but narrower than elytra; elytra strongly elongate and flattened, at suture about 1.2 times as long as pronotum; abdomen subparallel, slightly narrowed apically. Male: tergite VIII truncate apically ( Fig. 4 ); sternite VIII arcuate apically ( Fig. 5 ); median lobe of aedeagus with narrow bulbus and wide tubus in dorsal view ( Fig. 3 ), in lateral view apex of tubus truncate ( Fig. 2 ), internal sac as illustrated ( Fig. 2, 3 ). Female: tergite VIII arcuate apically ( Fig. 6 ); sternite VIII broadly rounded apically ( Fig. 7 ); spermatheca S-shaped ( Fig. 8 ).

Distribution. Origin: Nearctic. Canada: NF. USA: not recorded.

Collection and habitat data. Habitat: not recorded but probably riparian habitats as in other members of the genus. Collecting period: V. Collecting method: not recorded.

Comments. This species is easily distinguishable externally from H. pseudodiosica and H. dulcis , which have similarly shaped antennae, in having larger body and longer and wider elytra. Spermatheca of H. borealis is similar to that of H. dulcis but has slightly different shape of capsule and more tightly curved stem ( Fig. 8 ). Externally, the female holotype of H. borealis agrees with characteristics of the genus Hydrosmecta but males are needed for confirmation. The median lobe of the aedeagus has some unique features and likely was slightly damaged. More males are needed for study to confirm the morphology of the median lobe of the aedeagus and their affiliation with this species.

Figures

Figures 1–8. Hydrosmecta borealis Klimaszewski and Langor.1) Habitus in dorsal view.2) Median lobe of aedeagus in lateral view. 3) Median lobe of aedeagus in dorsal view. 4) Male tergite VIII. 5) Male sternite VIII. 6) Female tergite VIII.7) Female sternite VIII.8) Spermatheca. Scale line for habitus = 1 mm, remaining scale bars = 0.2 mm.