Anthrax hyalacrus Wiedemann 1828

Anthrax hyalacrus Wiedemann

Two specimens of A. hyalacrus were reared by Dr. Carl W. Rettenmeyer from nests of a trypoxylonid wasp (Hymenoptera: Sphecidae) on Barro Colorado Island, Canal Zone, Panama. The wasps were nesting in a cardboard carton in a clearing at the biological station.

Integument of pupa yellowish hyaline with yellow setae and reddish brown black-tipped tubercles and spines. Cephalic tubercles (Plate 2E) evenly spread, almost in a straight line; anterior tubercle short, compressed dorsoventrally, bluntly rounded apically, and with poorly defined dorsomesal and ventrolateral ridges toward apex; medial tubercle short, acuminate to blunt apex, with well-defined dorsolateral, ventrolateral, and mesal ridges; posterior tubercle short, curved slightly forward and bluntly rounded apically, connected to medial tubercle by sharp dorsolateral ridge, and with less distinct ventral and mesal ridges. Facial sclerite about eight times longer than narrowest width, with deep, square, narrow emargination at posterior end. Anterior facial tubercles short, broadly acuminate, flattened anteroposteriorly, narrowly separated or connected mesally. Posterior facial tubercle undeveloped, represented by rounded node.

Spiracles produced little above surrounding integument, without flanges; thoracic spiracle with about fifteen sections, posterior ones reduced; abdominal spiracles with about twelve sections, anteroventral ones reduced.

Sixth and seventh terga with numerous, small, single spines between setae. Eighth tergum with two spines on each side, one on each side of dorsolateral tumidities, one of dorsal pair sometimes absent; one seta also present on each side between tumidities rather than anterior to them. Medial process on ninth tergum short, narrow, acuminate. Anal tubercles (Plate 3H) short and thick, slightly curved upward apically, separated mesally by about two-fifths of medial width of one lobe; each tubercle with short, spinelike, dorsal and ventral denticles about one-third of way to apex, ventral one sometimes reduced; ventromesal margin with sharp ridge extending about two-thirds of distance to apex, without denticles; dorsomesal margin with sharp denticle about three-fourths of distance to apex; apex bluntly acuminate beyond preapical denticle.

The pupa of A. hyalacrus is most similar to pluricellus, aterrimus, and argyropygus argyropygus. Relationships of the four species are discussed under pluricellus.

Anthrax hyalacrus Wiedemann

Anthrax hyalacrus Wiedemann, 1828, p. 315.

Anthrax acroleuca.—Curran, 1934, p. 363, [not Wiedemann, 1828].

MALE.—Integument black; velvety black pruinose on discs of mesonotum, scutellum, and abdominal terga; silvery pruinose along margins of eyes, grayish or brownish pruinose elsewhere. Setae and scales on front black; face with black setae above extending to bases of antennae, with black or mixed black and white setae below. Setae and scales on occiput and fringe of hairs on posterior margin black. First antennal segment about as long as apical width, second segment globular; third segment flattened mesolaterally, tapering gradually to styliform part; style about half as long as styliform part (Figure 98).

Setae, pile, and scales on thorax and coxae black. A few black hairs usually behind spiracle. Anterior corner of hypopleuron with a small patch of hairs.

Wing (Plate 4f) velvet black basally, hyaline apically. Pigment extending out to a line running from tip of cell Sc along vein R1 to a point about halfway between bases of cells R2+3 and R4 and thence posteriorly through base of cell 2M2 to tip of cell 1A. Veins in pigmented portion black, in hyaline portion light brown. Cell 2A slightly wider than cell 1A. Stigmatic area pigmented. Calypter pigmented, fringe of hairs black. Halter black with light-tipped knob.

Femora and tibiae with dense, black scales; hind femur, tibia, and tarsus sometimes with dense, overlapping, cuneate white scales. Middle femur with one or two large postmedial bristles anteriorly and up to three bristles anteroventrally; posterior femur with five to seven short bristles anteroventrally.

Pile and scales on first five abdominal terga black; pile dense laterally. Sixth and seventh terga and posterolateral margins of fifth with laterally produced, dense, overlapping, truncate silver scales, or silver scales restricted to posterolateral margins of sixth and seventh terga.

MALE GENITALIA (Figure 57).—Gonocoxites very narrow apically, tapering to acute apices in lateral view, apices sharply rounded and separated mesally by a distinct sulcus; setae on gonocoxites evenly distributed, extending beyond medial fold. Basal segment of gonostylus long and thin in lateral view, with a number of coarse setae apically; distal segment elongate, oval, basal part bent slightly outward dorsally, with fine setae laterally on lower two-thirds. Apex of epiphallus flattened dorsoventrally, with a recurved, sharp lobe on each side and a short, triangulate apical plate above apex of aedeagus. Dorsal bands narrow, widely separated medially, without setae. Aedeagus very broad and bulbous basally, tapering apically to junction with ventral bands before lobes of apex of epiphallus.

FEMALE.—Similar to male. Apical margin of pigment on wing sometimes running apically along vein R4+5 for a distance of half width of cell R5. Posterior abdominal terga without silvery scales.

FEMALE GENITALIA (Figure 78).—Tenth tergum with about 31 spines on each side. Ventral arm of ninth tergum undulating, not enlarged apically. Dorsomedial angle of sclerite on each side of gonopore not produced, right angled; lateral arm narrow, not tapering, sharply rounded distally; ventral arm broadened parallel to meson and twisted. Spermathecal ducts about half as long as bulbs; first section very short; middle section about two-thirds as long as apical section which is about one-third as long as bulb, expanded apically and bent at almost a right angle medially; bulb elongate, tapering from apex to base, about three times longer than maximum width and with an enlarged, darker apical part.

DISTRIBUTION.—Anthrax hyalacrus occurs in equatorial and tropical forests from the Amazon Basin north into Panama and south into southern and eastern Brazil (Map 16).

TYPES.—Painter (unpublished notes) found two females of Anthrax hyalacrus at the Vienna Museum, one carrying the labels “Brasilia,” “hyalacra Coll. Winthem” and “hyalacra Wied. Brasilia” in Wiedemann’s handwriting, the other carrying the labels hyalacra Coll. Wiedem.” and “A. hyalacra in Amer. mer. Brasil.” Both specimens are abraded and the first lacks most of the antennae while the second is covered with fungus but has the left antenna complete. Because of the condition of the syntypes, no lectotype was chosen. A homotype compared by Painter leaves little doubt as to the identity of this species.

BIOLOGY.—Two specimens of hyalacrus were reared by Dr. Carl W. Rettenmeyer from nests of a Trypoxylonid wasp (Hymenoptera: Sphecidae) on Barro Colorado Island, Canal Zone. The wasps were nesting in a cardboard carton in a clearing at the Biological Station.

MAP 16.—Distribution of Anthrax hyalacrus.

Anthrax hyalacrus adalah spesies lalat yang berasal dari genus Anthrax dan famili Bombyliidae. Lalat ini juga merupakan bagian dari ordo Diptera, kelas Insecta, filum Arthropoda, dan kingdom Animalia.

Lalat ini biasanya memakan nektar dan polen yang ada dalam bunga.