Hemiquedius castoris Brunke & Smetana

Brunke, Adam, Smetana, Ales, Carruthers-Lay, Duncan & Buffam, Joel, 2017, Revision of Hemiquedius Casey (Staphylinidae, Staphylininae) and a review of beetles dependent on beavers and muskrats in North America, ZooKeys 702, pp. 27-43 : 30-32

Hemiquedius castoris Brunke & Smetana sp. n. Figs 1A, B, E, 2F, 3A, 4 map

BINs (shared with H. infinitus ).

BOLD:ACL9384 + BOLD:ABW6323

Type locality.

Gatineau Park, Outaouais region, Quebec, Canada.

Type material. Holotype (♂, CNC). "hutte à castor " [=beaver lodge] [small label] / Lac Fortune, Parc Gatineau, Qué, 15.VIII.1976, R. Sexton / CNC Coleo DNA Barcode voucher 00251682 / Barcode of Life, DNA voucher specimen, Sample ID CNC COLEO 00251682, BOLD Proc. ID: CNCCJ3033-14 [blue label].

Paratypes.

(19 ♂ 17 ♀ CNC, 22♂ 19 ♀ DEBU): CANADA: New Brunswick: Kent Co.: Kouchibouguac National Park, 19.XI.1977, Campbell and Smetana, (5, CNC); same except S.J. Miller (1, CNC). Ontario: Bruce Co.: Stokes Bay, beaver lodge, 1.VI.2008, S.A. Marshall (1, DEBU); Chatham-Kent Co.: Rondeau Prov. Park, Marsh Trail, ex. muskrat nest in marsh, 4.VI.1985, A. Davies and J.M. Campbell, specimen CNC656084 with BOLD Proc ID CNCCJ3032-14 (8, CNC); Kenora Distr.: 4 mi E. Alcona, 18.VI.1973, Campbell and R. Perry (2, CNC); Ignace, 16.VI.1973, Campbell and Perry (1, CNC); 47 mi S. Pickle Lake, 22.VI.1979, Campbell and Perry (1, CNC); Ottawa Reg., South March, ex. muskrat, 3.V.1969, A. Smetana, BOLD Proc ID CNCCJ3034-14 (1, CNC); Ottawa, Mer Bleue, 3.VII.1973, Smetana and Davies (1, CNC); Thunder Bay Distr.: 52 mi N Hurkett, Black Sturgeon Lake, 28.VI.1973, R. Perry and J. M. Campbell (1, CNC). Quebec: Outaouais Reg.: Gatineau Park, Lac Fortune, hutte à castor , 26.VIII.1976, R. Sexton (1, CNC, 5 DEBU); same except 27.VIII.1976 (1, DEBU); same except 21.VIII.1976 (5, DEBU); same except 29.VIII.1976 (1, CNC); same except 15.VIII.1976 (4, DEBU); same except 6.IX.1976 (1, DEBU) Gatineau Park, Blind Lake, 8.VIII.1969, J. M. Campbell (7, CNC); same except 11.XI.1970, J.M. Campbell and S. Peck (2, CNC); Gatineau, Old Chelsea, hutte de castor , 4.IX.1976, J.F. Laundry (3, CNC); Gatineau Park, Old Chelsea, hutte castor , 26.VIII.1975, R. Sexton (1, DEBU); Gatineau Park, Hay Lake, ex. beaver lodge, 2.X.1976, Campbell and Sexton (1, CNC); Gatineau Park, Lac Hay, hutte à castor , 2.X.1976, R. Sexton (3, DEBU); Gatineau Park, Meech Lake, 8.XI.1967, (1, CNC); Gatineau Park, Lac Kidder, hutte à castor , 10.X.1976, R. Sexton (2, DEBU); Perkins, hutte à castor , 25.VIII.1976, R. Sexton (4, DEBU); Gatineau Park, Lac Holly, hutte à castor , 11.IX.1976, R. Sexton (3, DEBU); Val-des-Monts, Lac Clermont, hutte à castor , 26.VI.1976, R. Sexton (4, DEBU); same except 1.VII.1976 (1, DEBU); same except 28.VI.1976 (1, DEBU); same except 12.VI.1976 (3, DEBU); Quyon, Pontiac, hutte à castor , 5.IX.1976, R. Sexton (3, DEBU); St. Pierre de Wakefield, hutte castor , 11.XI.1975, R. Sexton (1, DEBU).

Diagnosis.

Hemiquedius castoris can be easily distinguished by the setose lateral portions of the elytral disc (Fig. 1B) and the coarse meshed microsculpture on the entire surface of the scutellum (Fig. 1B). Hemiquedius infinitus and H. castoris cannot be distinguished by their CO1 barcodes.

Description.

Measurements ♂ (n = 5): HW/HL 1.11-1.16; PW/PL 1.01-1.07; EW/EL 0.99-1.04; ESut/PL 0.71-0.77; PW/HW 1.21-1.26; forebody length 5.05-5.81 mm.

Measurements ♀ (n = 5): HW/HL 1.18-1.20; PW/PL 1.02-1.06; EW/EL 0.94-0.97; ESut/PL 0.74-0.77; PW/HW 1.23-1.26; forebody length 5.21-6.06 mm.

Similar to Hemiquedius ferox and differing only in the following: palpi and antennae slightly darker, dark brown to dark reddish brown; antennae on average slightly thinner and shorter in appearance, in most specimens antennomere 8 and 9 slightly less elongate; head slightly more transverse in females rather than males; pronotum slightly wider than long; elytral disc with dense fine setae on lateral portion, scutellum with distinct, transverse meshed microsculpture on entire surface; punctures on abdominal tergites slightly denser; median lobe narrowed to shorter apex, length and shape of narrow apical portion highly variable (as in Fig. 2D); median lobe in parameral view with obtuse apex (as in Fig. 2C); paramere more strongly constricted at base (as in Fig. 2C); paired lobe of paramere elongate relative to that of H. infinitus (Fig. 2F); apical margin of male sternite VIII without or with barely discernable emargination (Fig. 1E); female tergite X in most specimens with median extension broader at base and more strongly constricted from lateral margin.

Etymology.

We describe this species in honor of Canada on its 150th birthday. Like its national animal, the North American Beaver, Canada promotes a diverse community within its greater environment. The species epithet refers to the close association of this rove beetle with beaver lodges.

Distribution.

Figure 4. This species is currently known only in Canada from northern Ontario to New Brunswick but very likely occurs broadly across eastern North America where beavers and muskrats occur. Its distribution includes both the boreal and deciduous forest regions.

Bionomics.

All specimens with collecting data have been taken from the nest material within beaver or muskrat lodges, some of which were abandoned for several years. Teneral specimens have been collected in August and September.

Comments.

Hemiquedius castoris is most similar to the sympatric H. infinitus but can be easily distinguished based on the fine setation on the elytral disc. The genitalia of these two species are extremely similar and only differ by the shape of the paramere (Fig. 2F vs. 2G). It is interesting to note that all boreal records of Hemiquedius represent H. castoris . Hemiquedius castoris is not likely to be sympatric with H. ferox as its host, the North American Beaver, does not occur naturally in peninsular Florida ( Peck 2007).