Aegialia lacustris Le Conte

Aegialia (Psammoporus) lacustris LeConte

Aegialia lacustris LeConte, 1850:225—Horn, 1871:293; 1887:101

Aegialia (Psammoporus) lacustris—Brown, 1931:44—Hatch, 1971:441—Stebnicka, 1977:471

DESCRIPTION—Length 370 to 530 mm, greatest width 190 to 270 mm Form convex, widest in apical half (Figure 6) Color reddish brown to nearly black except prosternum, leg usually paler Head coarsely punctate, punctations separated by less than to slightly more than a diameter, or almost contiguous; clypeus coarsely granulate, apex broadly, distinctly emarginate, gena produced Pronotum shiny, coarsely punctate throughout, punctations separated by less than to a diameter on disc, becoming denser at anterior, posterior angles, basal margin usually with lateral sinuation Elytron shiny or slightly alutaceous with humerus feebly dentate, interval convex or flat, impunctate, stria impressed with moderate punctations separated by less than to a diameter Metasternum smooth, very finely punctate medially, alutaceous, impunctate laterally Anterior tibia with external teeth reduced, not sharply separated, or pronounced, distinctly separated; middle tibia with sparse surface denticles and incomplete transverse carina; hindtibia with surface denticles on inner margin, 2 short, incomplete transverse carinae on outer margin, apical spurs slender, slightly spatulate, as long as first 2½ tarsal segments Male genitalia as in Figure 38; female genital plate as figured by Stebnicka (1977, fig 109)

LECTOTYPE—Designated herein LeConte (1850) did not state how many type specimens he had Therefore, we designate a male from his collection labeled “(pale blue disc)TYPE 3722[red paper]/Aegialia lacustris Lec” as the lectotype There are 2 additional specimens in the series bearing pale blue discs that may also be type material, but we do not so designate them

TYPE LOCALITY—“Lake Superior”

TYPE DEPOSITORY—MCZ

REMARKS—The key characters will distinguish A lacustris from the other species of Psammoporus; however, A lacustris can be divided into 2 more or less recognizeable forms Form A (typical lacustris) is characterized by the following: head with punctations not contiguous, usually sparse medially, coarser than in form B; pronotal punctations separated by less than to a diameter, slightly coarser than in form B; external teeth on anterior tibia blunt, reduced (not consistent depending on age of specimen); elytron with interval convex; large sclerite in male internal sac apically truncate or somewhat bifurcate; eastern Canada to Alberta and the Colorado Front Range Form B is characterized by the following: head with punctations dense, nearly contiguous throughout, finer than in form A; external teeth on anterior tibia pronounced, distinctly separated; elytron with interval flat; large sclerite in male internal sac produced, somewhat acuminate apically; Colorado Front Range to Washington and British Columbia These differences would normally indicate the presence of 2 closely similar species, especially since both occur in the Front Range of Colorado; however, a large series of specimens collected at Rampart House, Alaska, is intermediate in all respects between forms A and B We therefore consider A lacustris to be a widespread, polymorphic species with morphological differences attributable to population disjunctions as figured by Stebnicka (1977, fig 121)

DISTRIBUTION—Newfoundland to the Great Lakes region, west to Alaska, northern California, and New Mexico New Records: Canada, Alberta: Ghost Dam Quebec: Duparquet Saskatchewan: Davis Creek Yukon: Dawson USA, Alaska: Rampart House California: Lake Co, Twin Lakes; Mt Lyall; Placer Co; Siskiyou Co, 16 mi NE McCloud; Tuolumne Co, 34 mi (547 km) NE Strawberry Colorado: Alma; Georgetown; Long's Peak Inn; Ouray Idaho: Priest Lake Michigan: Horn Mt Club Montana: Bear Paw Mt; Chief Mt New Mexico: Cowles, Pecos Baldy; Lincoln Co, Sierra Blanca, 11,500 ft (3505 m); Red River Village, 3 mi (48 km) W; Santa Fe, NE of ski area Nevada: Washoe Co, Summit Oregon: Blue Mts; Wallowa Co, Wallowa Mts Utah: Alta; Park City; Timpanogas, Aspen Grove Washington: Easton; Sprague; Tampico Wyoming: Grand Teton Park; Yellowstone National Park