Hydrosmecta canadensis Webster and Klimaszewski, 2017

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 : 6-7

Hydrosmecta canadensis Webster and Klimaszewski , new species

( Fig. 17–24 )

Holotype (male): Canada, New Brunswick, Queens Co., Bayard, at Nerepis River , 45.4426°N, 66.3280°W, 25.V.2008, R. P. Webster // river margin, under small rocks in gravel ( CNCI) . Paratypes: Canada, New Brunswick, Queens Co., Bayard, at Nerepis River , 45.4426°N, 66.3280°W, 25. V.2008, R. P. Webster // river margin, under small rocks in gravel ( LFC) 1 male, 1 female, ( RWC) 2 males, 1 female ; Bayard, at Nerepis River , 45.4426°N, 66.3280°W, 30. V.2008, R. P. Webster // river margin, under small rocks in gravel ( RWC) 2 females ; Bayard, at Nerepis River , 45.4426°N, 66.3280°W, 7. VI.2017, R. P. Webster // river margin, in gravel near water ( NBM) 1 female ( RWC) 1 female ; York Co., 1.5 km N of Durham Bridge, 46.1408°N, 66.6179°W, 15. VII.2008, R. P. Webster, Nashwaak River // river margin, among cobblestones near outflow of brook ( RWC) 1 male .

Etymology. Named after Canada, the country of origin of the type series, and to commemorate the 150 th anniversary of Canada.

Diagnosis. Body length 2.0– 2.1 mm; subparallel, flattened, light brown with head and abdomen dark brown, legs and basal antennomeres yellow ( Fig. 17 ); moderately glossy, with fine and dense puncta- tion and pubescence; faint meshed microsculpture present on forebody; head as wide as pronotum, postocular area about as long as diameter of eye, posterior angles rounded; eyes moderately large; antennae long, reaching posterior margin of elytra, all antennomeres distinctly elongate, antennomere XI at least as long as two preceding antennomeres combined; pronotum subquadrate, widest in apical third, as wide as head and abdomen but narrower than elytra, slightly depressed medially; elytra elongate and flattened, at suture slightly longer than pronotum; abdomen subparallel, slightly nar- rowed apically. Male: tergite VIII broadly arcuate apically ( Fig. 20 ); sternite VIII longer than wide, apical margin arcuate, laterally rounded, antecostal suture widely separated from basal margin ( Fig. 21 ); median lobe of aedeagus in lateral view with large bulbus, tubus triangular, with venter sinuate, with small, narrow basal projection moderately widely separated from tubus ( Fig. 18 ); in dorsal view tubus subparallel medially ( Fig. 19 ). Female: tergite VIII truncate apically ( Fig. 22 ); sternite VIII with apical margin straight in middle third, broadly rounded laterally ( Fig. 23 ); spermatheca with capsule short with moderate-sized apical invagination, stem sinuate and broadly looped posteriorly with base slightly swollen ( Fig. 24 ).

This species is very similar to H. caduca , from which it may be distinguished by generally slightly longer and broader body, more elongate apical antennomeres, basal projection of bulbus shorter and more widely separated from tubus in lateral view ( Fig. 18 ), subparallel median part of tubus in dorsal view ( Fig. 19 ), and spermathecal coils slightly less tight ( Fig. 24 ).

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

Collection and habitat data. Habitat: This is a riparian species associated with gravel and sand near river margins ( Fig. 48 ). Most specimens were collected from under small rocks in gravel along river margins; one individual was found among cobblestones near the outflow of a brook into a river. Collecting period: V, VI. Collecting method: examining gravel and aspirating specimens.

Figures

Figure 48. Gravel bar habitat at Nerepis River, Queens Co., Bayard, NB, habitat for Hydrosmecta caduca Casey, H. canadensis Webster and Klimaszewski, sp. nov. (type locality),H. dulcis Casey, andH. minutissimoides Webster and Klimaszewski, sp. nov. (type locality).

Figures 17–24. Hydrosmecta canadensis Webster and Klimaszewski, sp. nov. 17) Habitus in dorsal view. 18) Median lobe of aedeagus in lateral view. 19) Median lobe of aedeagus in dorsal view. 20) Male tergite VIII. 21) Male sternite VIII. 22) Female tergite VIII. 23) Female sternite VIII. 24) Spermatheca. Scale line for habitus = 1