Hydrosmecta dulcis Casey, 2000

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 : 7

Hydrosmecta dulcis Casey

( Fig. 25–31 )

Hydrosmecta dulcis Casey 1910: 87 .

Lectotype (female): Bayfield, Wisconsin, Wickham; dulcis Csy. ; Type USNM 39084 ; Casey bequest 1925 ; Lectotypus: Hydrosmecta dulcis Casey, V.I. Gusarov 2000 (USNM). Present designation. Examined.

New Canadian records: Canada, New Brunswick, Queens Co., Bayard, at Nerepis River , 45.4426°N, 66.3280°W, 25.V.2008, R. P. Webster // river margin, splashing fine sand ( LFC) 1 female, ( RWC) 1 fe- male ; New Brunswick, Queens Co., Bayard, at Nerepis River , 45.4426°N, 66.3280°W, 30.V.2008, R. P. Webster // river margin, under small rocks in gravel ( RWC) 1 male .

Diagnosis. Body length 2.0– 2.3 mm; subparallel, flattened, light brown with head, pronotum, bases of elytra and abdomen dark brown and legs yellow ( Fig. 25 ); moderately glossy, with fine and dense punctation 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, almost reaching posterior margin of elytra, antennomeres I–III distinctly elongate, IV–X slightly elongate, XI only slightly longer than preceding antennomere; pronotum slightly transverse, shorter than head, widest in middle of its length, as wide as head and abdomen but narrower than elytra, slightly depressed medially; elytra elongate and flattened, at suture about one-fourth longer than pronotum; abdomen subparallel, slightly narrowed apically. Male: tergite VIII broadly arcuate apically ( Fig. 27 ); sternite VIII longer than wide, evenly rounded apically, antecostal suture widely separated from basal margin ( Fig. 28 ); median lobe of aedeagus with large bulbus, tubus short triangular, arcuate and strongly produced ventrally in lateral view ( Fig. 26 ). Female: tergite VIII very broadly arcuate apically ( Fig. 29 ); sternite VIII about evently rounded apically ( Fig. 30 ); spermatheca S-shaped, capsule club-shaped with moderate-sized apical invagination, stem slightly swollen at base ( Fig. 31 ).

Distribution. Origin: Nearctic. Canada: NB. USA: WI.

Collection and habitat data. Habitat: this is a riparian species associated with gravel and sand near river margins ( Fig. 48 ). Adults in NB were found in sand or under small rocks in gravel. Collecting period: V, VI. Collecting method: splashing fine sand at river margin or aspirating from gravel.

Comments. This is the first record of this species from Canada and NB. We have compared the lectotype female with our female and it agrees with the lectotype in shape of spermatheca, tergite and sternite VIII and external characters, including similar size and antennae (length and width of antennomeres), shape, color and pubescence pattern. The lectotype has slightly wider elytra than our female from NB. Because Gusarov’s lectotype designation was never published, we formally designate this female specimen as the lectotype with our designation label. The male and female of this species are described and illustrated for the first time, including genital structures, based on the specimens from NB.

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 25–31. Hydrosmecta dulcis Casey.25) Habitus in dorsal view.26) Median lobe of aedeagus in lateral view. 27) Male tergite VIII. 28) Male sternite VIII. 29) Female tergite VIII. 30) Female sternite VIII. 31) Spermatheca. Scale line for habitus = 1 mm, remaining scale bars = 0.2 mm.