Comprehensive Description

provided by Smithsonian Contributions to Zoology
Anthrax luctuosus Macquart

Anthrax luctuosus Macquart, 1840, p. 70 [luctuosa].—Paramonov, 1947, p. 95.

Argyramoeba luctuosa.—Schiner, 1868, p. 123 [Argyromoeba].—Kertéaz, 1909, p. 65.

MALE.—Integument mostly black; femora, trochanters, tibiae, metapleura, lateral margins of abdominal terga, and abdominal sterna yellow; discs of mesonotum, scutellum, and abdominal terga velvety black pruinose; face, lateral margins of front, and lower part of occiput silver pruinose; remainder of integument grayish or brownish pruinose. Front with fine, black setae and sparse linear black scales; face with dense, white setae extending to antennae and a few black setae. Occiput with short setae, white below, black above, and a few linear, recumbent black scales; fringe of pile on posterior margin white on lower two-thirds, yellowish white on upper third. First antennal segment about as long as wide; second segment globular, subequal in diameter to first segment and basal part of third segment; basal part of third segment flattened laterally, tapering gradually to styliform part; styliform part about three times as long as style (Figure 99).

Discs of mesonotum and scutellum with sparse, fine black setae and linear, recumbent black scales; lateral margins with linear, woolly scales, white anteriorly, black posteriorly, and brown medially. Pile, scales, and setae on mesopleuron and sternopleuron white; black setae and hairs sometimes present. Pile on propleuron, prosternum, and anterior margin of mesonotum white. Pteropleuron with white or mixed black and white setae and scales anteriorly, with woolly, linear, gold or yellowish-white scales posteriorly. Fore coxa with white setae and scales; middle and hind coxae with coarse, white or mixed black and white setae and scales. Postalar tuft of pile black. A tuft of white hairs behind spiracle on metapleuron. Hypopleuron bare.

Wing (Plate 4l) hyaline apically, velvet black basally out to a line perpendicular to wing axis running from tips of cells 1A and 2A through extreme bases of cells R2+3 and R5 to vein R1 and slightly further apically in cells Sc and C. Cells C and Sc yellowish beyond margin of black. R–m crossvein at basal one-fifth to one-third of vein M1+2. Contact of cells 1M2 and Cu1 less than half of width of base of cell Cu1. Cell 1A closed at wing margin. Cell 2A enlarged posteriorly, more than 1.5 times as wide as cell 1A. Stigmatic areas in cell M pigmented. Alula well developed, posterior margin slightly convex. Calypter pigmented, fringe of hairs light brown. Stem of halter reddish brown, knob yellow.

Scales on femora and tibiae black. Middle femur without distinct bristles anteroventrally; hind femur with three to five short bristles anteroventrally. Hind tibia with a single row of macrochaetae anterodorsally.

Lateral margins of first abdominal tergum with dense, silvery-white pile; pile on sides of second to fourth terga brown, black, or mixed. Posterior margin of first tergum with a dense patch of lanceolate, truncate, medially-directed, silvery-white scales laterally. Discs of terga two, three, and four, mesal half of posterior margin of first tergum, and mesal half of fifth tergum with sparse, fine black setae and linear, recumbent black scales. Lateral parts of fifth tergum and all of terga six and seven with dense, overlapping, truncate, posterolaterally directed, silvery-white scales. Venter with sparse, fine white setae and linear scales.

MALE GENITALIA (Figure 54).—Gonocoxites broad, dorsal margin attenuating abruptly to sharply rounded tips in lateral view, mesal margins curving outward and recurving inward to widely separated, sharply rounded apices in ventral view; a few setae toward the base and some scattered setae apically. Basal segment of gonostylus convex dorsally, not extending past distal segment in ventral view; distal segment with an acuminate ventral lobe from which the structure curves upward and curls over dorsally. Apex of epiphallus narrow, with an acuminate, nearly vertical dorsal spine and ventrolateral lobes rounded apically in lateral view; dorsal bands narrowly separated mesally. Base of aedeagus narrow, gradually tapering to junction with ventral bands below approximation of dorsal bands.

FEMALE.—Similar to male. Posterolateral margins of terga five and six with overlapping, truncate, silver scales, and white setae; remainder of posterior terga with black setae and scales. Sterna with black, white, or mixed black and white setae and scales.

FEMALE GENITALIA (Figure 81).—Tenth tergum with about 14 spines. Ventral arm of ninth tergum narrow, parallel sided, not enlarged apically. Dorsomedial angle of sclerite on each side of gonopore extending mesally as a short, broadly rounded lobe as wide as lateral arm; lateral arm parallel sided, slightly enlarged at obtusely angular apex; ventral arm broadened medially parallel to meson, straight and narrow in dorsointerior view. Spermathecal ducts about twice as long as bulb; first and second sections short, about equal in length; third section about as long as basal two; second divisional collar enlarged, about twice as wide as first; bulb globoid, symmetrical, slightly longer than wide.

DISTRIBUTION.—Specimens of A. luctuosus have been collected from southern Mexico through the Amazon Basin into southeastern Brazil (Map 12). This is one of the few species that seems to be adapted to areas of tropical or equatorial forest as well as desert areas.

MAP 12.—Distribution of Anthrax luctuosus.

TYPE.—According to Painter (personal notes) the type female of A. luctuosus is in the Paris Museum. It is headless, mostly denuded, and has only part of one hind leg present. It carries the green museum label “A. luctuosa Macqt. Cayenne” and “1610,” and pin labels “No. 898 Anthrax luctuosa” and “128, 38.”

Although Macquart wrote “Patrie inconnue,” in his personal copy in the Paris Museum this has been crossed out with “Cayenne” written in. Thus, the type-locality is probably Cayenne, French Guiana.
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bibliographic citation
Marston, Norman L. 1970. "Revision of New World species of Anthrax (Diptera: Bombyliidae), other than the Anthrax albofasciatus group." Smithsonian Contributions to Zoology. 1-148. https://doi.org/10.5479/si.00810282.43