Anthrax stellans (Loew 1869)

Anthrax stellans (Loew)

Argyramoeba stellans Loew, 1869, p. 28 [Argyramoeba].—Coquillett, 1894, p. 95.—Kertész, 1909, p. 67.

Spongostylum stellans.—Aldrich, 1905, p. 223 [Spogostylum].—Cole and Lovett, 1921, p. 244 [part] [Spogostylum].

Anthrax stellans.—Painter and Painter, 1965, p. 432.

Argyramoeba pluto.—Osten Sacken, 1877, p. 244 [part].—Osten Sacken, 1878, p. 90 [part] [not Wiedemann, 1828; misidentification].

Anthrax pluto.—Johnson, 1925, p. 108.—Curran, 1927, p. 85 [not Wiedemann, 1828; misidentification].

MALE.—Scales on head black, white, and sometimes brown. Second antennal segment saucer shaped with apical margin produced as sharp flange.

Scales on mesonotum mostly black, few white and brown ones present, especially along margins. Scutellum with white, brown, and black scales. Pile on mesopleuron and pteropleuron black, white, and brown. Scales on pleura white and brown. Prosternum, propleuron, and anterior margin of mesonotum with mixed brown, white, and black pile. Postalar tuft of pile black, few white hairs sometimes present, some white scales basally. Scales on coxae white, few brown ones sometimes present.

Cell C of wing (Plate 2a) entirely infuscated or partly subhyaline beyond humeral crossvein; cell Sc infuscated except apex and stigmatic area. Remainder of wing with coalesced spots at bases of cells Cu1, 1M2 and R1, R2+3, and R5, R, and 2M, and extending from vein M1+2 to vein R1 midway between bases of cells R2+3 and R4. Isolated spots at bases of cells R4, M1, and 2M2, below tip of R1 in cell R1, apically and subapically on vein R2+3, medially and apically on vein R4, apically on vein M2, medially on m crossvein, and apically on vein Cu2. A large, poorly defined spot medially on vein 2A extending across cell 1A and halfway across cell 2A. Cell 2M hyaline to partly infuscated medially. A small spot often present apically on vein Cu1.

Fore and middle femora with white scales posteroventrally and black scales anterodorsally, some golden-brown scales present between black and white ones. Hind femur with golden-brown scales ventrally and black scales elsewhere. Sometimes a few white scales basally.

Pile on sides of first abdominal tergum white, few black hairs posteriorly; posterior margin with white scales laterally and black scales medially. Sides of terga two through six with black pile and scales, with some white and brown scales, especially posteriorly; white scales on sides of seventh tergum. Discs of terga two through five with black scales; posterior margins with submedial and sublateral patches of white scales, patches on two and three often enlarged and coalesced, sublateral patches on four and submedial patches of five reduced; some brown scales sometimes mixed with white. Terga six and seven with black scales medially and white scales laterally. Scales on first sternum threadlike, white; posterior sterna with white scales apically and golden-brown scales preapically and sometimes basally.

FEMALE.—Similar to male. Infuscation of wing (Plate 2b) more extensive; cell 2M and apical portion of cell R often entirely infuscated; spots in distal portion of wing larger. White scales more extensive on femora, sometimes occupying as much as one-third of ventral margin of hind pair.

MALE GENITALIA (Figure 30).—Similar to pluto pluto. Apex of epiphallus flared; apex of aedeagus enlarged, slightly flared, gonopore apical.

FEMALE GENITALIA—Similar to seriepunctatus. Ducts of spermathecae with two convolutions before expanding to bulbs.

BODY LENGTH.—8.5 to 11.5 mm.

WING LENGTH.—7.6 to 10.6 mm.

DISTRIBUTION.—Anthrax stellans occurs in coniferous forests in Canada, south along the Coast Range and Sierra Nevada into southern California, in the Rocky Mountains into Colorado and central Utah, and at higher elevations along the Canadian border in northeastern United States (Map 8). It may occur as far north as the extent of the spruce forests in northern Canada.

A series of specimens from Tifton County, Georgia, appear to belong to this species. If so, they are probably a relict population surviving from the last glaciation.

TYPES.—The type, which is in the Museum of Comparative Zoology at Harvard University, is badly rubbed and molded. Contrary to Loew's statement, the type is a female. The type-locality is “Oregon.”