Proteinus parvulus LeConte, 1863

Webster, Reginald P., Davies, Anthony E., Klimaszewski, Jan & Bourdon, Caroline, 2016, Further contributions to the staphylinid fauna of New Brunswick, Canada, and the USA, with descriptions of two new Proteinus species (Coleoptera, Staphylinidae), ZooKeys 573, pp. 31-83 : 38-41

Taxon classification Animalia Coleoptera Staphylinidae

Proteinus parvulus LeConte, 1863 Figs 5-9

Material examined.

Alberta, Canmore, 5.VIII.1961, B.F. & J.L. Carr, Lot 3, toadstools in pine + spruce forest, (1 ♂, CNC); Twp 28, Rge 5, W 5 Mer, 10.IX.1981, B.F. & J.L. Carr, Lot 1, fungus & litter in pine, spruce, poplar forest (1 ♂, CNC); same data except 3.VIII.1979, Lot 3, Twp 34, Rge 7, W 5 Mer, 9.VIII.1980, B.F. & J.L. Carr, Lot 1, evergreen logs (1 ♂, CNC). British Columbia, Yoho National Park, Amiskwi River [near junction of Kiwetinok River], 6000', 7.VIII.1971, J.M. & B.A. Campbell (5 ♂, 4 ♀, CNC). Manitoba, Riding Mountain National Park [RMNP], 6 km E of Clear Lake, 24.VIII.1979, D.B. Lyons, ex agaric mushrooms (18 ♂, 1 ♀, CNC); same data except ex pile of rotting mushrooms (2 ♂, CNC); RMNP, Katherine Lake, 13.VI.1979, D.B. Lyons, ex Russula sp. (2 ♂, CNC); RMNP, Moon Lake, 21.VIII.1979, S.J. Miller, berlese ex mushrooms (3 ♂, 1 ♀, CNC). New Brunswick, Madawaska Co., near Falls Brook Falls, 47.5877°N, 68.3687°W, 16.X.2013, R.P. Webster & M. Turgeon // Spruce & balsam fir forest, in decaying mushroom (1 ♂, RWC); Saint John Co., Dipper Harbour, 45.1176°N, 66.3806°W, 24.VIII.2006, R.P. Webster, coll. // Red spruce & balsam fir forest, in decaying gilled mushrooms (5 ♂, RWC); same data and forest type but 12.IX.2006, on gilled mushrooms (4 ♀, 1 ♂, RWC). Saskatchewan, Hwy. 955, 63 km N La Loche, Clearwater River crossing campground, 4.VIII.1984, B.F. & J.L. Carr, Lot 1, almost dry pine/aspen litter (1 ♂, CNC). Yukon Territory, Dawson City, 11.VII.1968, J.M. Campbell & A. Smetana, sifting old Boletus mushrooms (1 ♂, 1 ♀, CNC); same data except 16.VII.1968, sifted rotten mushrooms (42 ♂, 38 ♀ CNC); Mile 14 W of Dawson, 3000', 3.VIII.1949, P. Bruggemann (2 ♂, CNC); Marsh Lake, 5.VIII.1987, B.F. & J.L. Carr, Lot 1, in fungus (1 ♂, 2 ♀, CNC).

Diagnosis.

Body length 1.5-1.8 mm, head black, pronotum and elytra dark brown and lighter than head; first two antennal segments testaceous, remaining segments dark brown becoming slightly darker toward last segment; legs testaceous; forebody and elytra with pubescence sparse, recumbent, directed posteriad; head and pronotum with distinct isodiametric microsculpture throughout, slightly stronger on head, punctures widely spaced, shallow; elytra with punctation coarse, sparse, with little microsculpture, thus appearing glossy; lateral margin of pronotum broadly arcuate, widest at middle, hind angle obtuse, slightly rounded; hind margin sinuate; mesosternum with disk irregularly rugulose, with anteromedial carinae short, subparallel, well-separated, mesosternal process narrow, with fine, short carina between middle coxae, gradually tapering to acute apex; metasternum depressed along anterior marginal bead, process very broadly rounded between middle coxae, disk sparsely pubescent; body shape and proportions as in Fig. 5. Male. Front tarsus with first tarsomere expanded, twice as long as wide, remaining tarsomeres normal; middle trochanter with posterior margin evenly rounded, without peg setae; middle femur with posterior margin broadly expanded in apical half, with series of 2-4 stout bullet-shaped setae along expansion and one closer to base; middle tibia very broadly arcuate, with small fin-like projection at apex of inner margin, without a series of peg-like setae; hind trochanter densely punctulate; hind tibia with inner margin abruptly narrowing in apical 1/4 in ventral aspect, with sparse short erect setae. Tergite VII triangular in shape, posterior margin truncate at apex (Fig. 8); posterior margin of sternite VII broadly rounded with a shallow semicircular emargination (Fig. 9). Median lobe of aedeagus with angular subapical part in lateral view, with indistinct internal structures as illustrated (Figs 6, 7). Female. Similar to male but first tarsal segment only slightly expanded; middle tibia nearly straight. Tergite VII similar in shape to that of male; sternite VII without emargination.

Distribution in Canada and Alaska.

YK, BC, AB, SK, MB, ON, NB ( Bousquet et al. 2013). Proteinus parvulus was described from "Lake Superior" but was reported from localities in ON from that region (Batchewana Bay and Michipicoten River) soon thereafter by Hubbard and Schwarz (1878), which probably represents the material on which LeConte based his description. This species is newly recorded from YK, BC, AB, SK, MB, and NB in Canada. This species is transcontinental in Canada.

Natural history.

In NB, Proteinus parvulus was found in a spruce and fir forest and a red spruce forest. Most specimens were found in decaying gilled mushrooms. Adults were collected in August, September, and October. Elsewhere in Canada, adults were collected during July and August from fungus and litter in a pine, spruce, and poplar ( Populus ) forest, in toadstools in a pine and spruce forest, in agaric mushrooms, in a pile of rotting mushrooms, in Russula sp. mushrooms, sifted from old Boletus mushrooms and rotting mushrooms, and from mushrooms.