Anthrax atriplex Marston 1970

Anthrax atriplex Marston

Two specimens of this species from the National Museum of Natural History were reared by Krombein (1967) from the nests of Megachile gentilis Cresson (Hymenoptera: Megachilidae). Pupal skins are pinned with the specimens.

Integument of pupa yellowish hyaline with yellow setae and reddish brown black-tipped spines and tubercles. Medial cephalic tubercle (Plate 1F) formed outside a line between anterior and posterior ones, and closer to posterior one; anterior tubercle of moderate length, tapering to acute apex, with sharp mesal ridge curving ventrally, sharp lateral ridge curving dorsally, and less distinct dorsal and ventral ridges basally; medial tubercle bent dorsolaterally from base at slight angle, broadly triangular basally, tapering to acute apex, with sharp ventrolateral ridge connecting to posterior turbercles, and sharp ventromesal ridge continuing around to posterior margin of cephalic area; posterior tubercle short, curving anteromesally to sharp apex, concave anteromesally, with sharp anterolateral, posterolateral, and posteromesal ridges. Facial sclerite about seven times longer than narrowest width, posterior end with shallow, broad emargination; anterior facial sclerites short, indistinctly united mesally, not flattened anteroposteriorly, with rugose surfaces tapering to sharp apices; posterior facial tubercle represented by low, binodal, transverse ridge. Bases of anterior facial setae distinctly in front of bases of anterior facial tubercles.

Thoracic spiracle with about eight sections, posterior ones reduced, with sharp flange around anterior two-thirds. Abdominal spiracles each with about six sections, the anteroventral ones reduced, with broad, sharp flange anteroventrally, narrowing anteriorly then broadening anterodorsally and forming sharp spur posteriorly.

Sixth and seventh terga without spines between setae. Eighth tergum without spines dorsally, with about three setae on each side in front of and mesad of dorsolateral tumidities. Ninth tergum with transverse, bifid, mesal process. Each anal tubercle (Plate 4G) about four times longer than medial width; tubercles separated mesally by about half the medial width of one tubercle. Each tubercle with strong dorsal and ventral denticles near base not connected by lateral flange (indistinct ridge sometimes present); ventromesal margin with denticle about halfway to apex extending basally as sharp flange; sharp dorsomesal and blunt, poorly defined, ventromesal denticles present about three-fourths of distance to apex; tubercle tapering outward from preapical denticles to bluntly acuminate, slightly incurved apex.

The relationship of A. atriplex to melanopogon and other species in the genus is discussed under melanopogon.

Anthrax atriplex

Argyramoeba pluto.—Osten Sacken, 1886, p. 102 [not Wiedemann, 1828; misidentification].

Anthrax atriplex Marston.—Krombein, 1967, p. 402.

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

Scales on mesonotum mostly black, some brown and white ones, especially along lateral margins. Scales on scutellum black and white, few brown scales sometimes present. Pile on mesopleuron and pteropleuron white and brown. Scales on pleura brown and white. Presternum, propleuron, and anterior margin of mesonotum with mixed black and white pile, some brown hairs on first two. Postalar tuft of pile mixed black and white. Scales on fore coxa brown and white.

Cell Sc of wing (Plate 2k) entirely infuscated except for stigmatic area and apex; cell C infuscated before humeral crossvein except for distal hyaline spot, subhyaline to hyaline beyond humeral crossvein. Remainder of wing with spots at bases of cells R4, M1, and 2M2, coalesced spots at bases of cells R2+3 and R5, Cu1, 1M2 and R1, and R and 2M; isolated spots in cell R1, below tip of vein Rl} apically and subapically on vein R2+3, on medial angle of vein R4, on medial angle of m crossvein, subapically on vein Cu2, and submedially on vein 2A (extending broadly into both cells 1A and 2A); transverse spot present medially on vein R4+5 extending across cell R2+3, and longitudinal spot present postmedially in cell R1.

Scales on fore and middle femora and tibiae black anteriorly, narrowly white posteriorly. Scales on hind femur and tibia entirely black.

Sides of first abdominal tergum with white pile, with few brown hairs posteriorly; posterior margin with white scales laterally and black scales medially. Sides of terga two through five with black pile and scales; sides of terga six and seven with few black scales and numerous white scales. Discs of terga two through five with black scales except for submedial and larger sublateral patches of lanceolate white scales on posterior margins; spots of white scales reduced laterally on segment four, coalesced medially on segment five; terga six and seven with black scales medially and white scales laterally. Scales on venter black and brown, few white scales present posterolaterally on two, five, six, and seven.

FEMALE.—Similar to male. Brown hairs less numerous on thoracic pleura, absent on prostemum and propleuron. Postalar tuft of pile almost entirely white. Spots on wing (Plate 2l) larger; cells C and 2M partially infuscated medially. Some white scales posteriorly on sides of abdominal terga; spots of white scales more extensive on discs of abdominal terga, few gold scales submedially on posterior margins of two and three. Scales on first abdominal sternum curly, linear, white; dark scales on remainder of sterna entirely black.

VARIATION.—The color of the linear scales on the posterodorsal part of the sternopleuron varies from white or yellow in the west to brown in the east. The remaining scales vary from white to yellowish white. The postalar tuft of pile varies from entirely white in some specimens from Texas to predominantly black in a few specimens from southern California. The brown hairs on the thoracic pleura are often absent in specimens from the western part of the range. The pigmentation of the wing may be slightly darker or lighter than that described for the types. There may be some yellowish or white scales along the posterior margins of the abdominal sterna, but the scales on the anterior parts of the sterna are always black.

MALE GENITALIA (Figure 31).—Similar to pluto pluto. Apex of epiphallus flared outward; apex of aedeagus enlarged, slightly flared, gonopore apical.

FEMALE GENITALIA (Figure 45).—Similar to pluto pluto. Tenth tergum with 12 spines on each side. Lateral arm of sclerite on each side of spermathecal ducts broad; ventral arm twisted. Ducts of spermathecae with two convolutions before expansion to bulbs; bulbs broadest postmedially.

BODY LENGTH.—6.9 to 11.0 mm.

WING LENGTH.—6.1 to 10.8 mm. DISTRIBUTION.—Anthrax atriplex occurs in the desert scrub zone in the southwestern United States from southern Texas to southern California, south into central and western Mexico and north in the Great Basin (Map 9). It is allopatric to melanopogon.

HOLOTYPE.—, 10 mi. NW Nogales, Santa Cruz Co., Arizona, IV–27–1961, 3600 feet (R. H. and E. M. Painter).

ALLOTYPE.—, same data as holotype.

PARATYPES.—Arizona: Cochise Co., Bowie, VI–23–1954 (G. D. Bulter); , 2 mi. NE Portal, V–18–1961 (R. H. and E. M. Painter); , 3 mi. W Rodeo, N. M., VII–9–1956 (H. and A. Howden); , VII–29–1927 (R. H. Beamer). Gila Co., 4 4, Globe, VII–27–1932 (R. H. Painter) 2, , Globe, V–9–23–1935 (Parker); , Wheatfields, near Globe, VIII–19 (D. K. Duncan); 8, Miami, VII–22–1932 (R. H. Beamer); , 2, Tonto National Monument, VII–26–1932 (R. H. Painter). Graham Co., , Thatcher, IX–6–1947 (E. J. Taylor). Pima Co., , Baboquivari Mtns., IV–29–1935 (F. H. Parker); 2, , Baboquivari Mtns., VII–24–1941 (R. H. Beamer and E. L. Todd); , Baboquivari Mtns., VI–19–1950 (L. D. Beamer); , Organ Pipe National Monument, IV–13–1947 (A. L. Melander); , Sabino Canyon, V–26–1962 (F. D. Parker and L. A. Stange); 2, Baboquivari Canyon, IV–9–1963 (R. C. Dickson); 2, , Saguaro National Monument, V–3, 9–1960 (G. Butler); Santa Catalina Mtns., V–11–1961 (J. Bequaert); , Santa Rita Mtns., VIII–9–1930 (R. H. Painter); , Santa Rita Mtns., VIII–18–1935 (E. I. Beamer); , Santa Rita Mtns., VII–20–1937 (Ruggles); 3, Sells, VII–31–1932 (R. H. Painter); , 25 mi. SE Sells, VIII–2–1932 (R. H. Painter); , Tucson, VIII–3–1930 (R. H. Painter); , Tucson, IX–3 (F. M. Carpenter); , , 36 mi. SW Tucson, VIII–3–1932 (R. H. Painter); , Tucson, IV–27–1948 (A. L. Melander); , Cat Pass, Tucson Mtns., VIII–29–1913 (W. D. Pierce). Pinal Co., , 20 mi. S Florence, VIII–3–1949 (F. Werner and W. Nutting); , Sacaton, VII–24–1932 (R. H. Painter); , Rimrock, IV–29–1925. Yavapai Co., 4, 3, 5 mi. N Wickenberg, IV–30–V–14–1937 (L. K. Gloyd).

MAP 9.—Distribution of Anthrax atriplex.

California: Los Angeles Co., Attadena, VI–8–1914; 5, Bautista Canyon, V–5–1931 (C. H. and D. Martin); , Tanbark Flat, VII–4–1950 (F. X. Williams); , Topango Canyon, VIII–5–1938 (Jean Russell). Riverside Co., , Anza, VIII–6–1935 (E. I. Beamer); , McCoy Spring, IV–9–1963 (E. I. Schlinger 1957 (H. R. Moffitt); , 4 mi. N Cajon Jct., VII–4–1958 (J. C. Hall). Santa Barbara Co., , Bluff Camp, San Rafael Mtns., VI–29–1959.

New Mexico: Dona Ana Co., , Las Cruces, IV–25–1954 (R. H. Beamer). Hidalgo Co., , Steins, VIII–8–1932 (R. H. Painter). Otero Co., , Alamagordo, IV–30–1902. , “Hot Springs,” VII–22–1950.

Texas: Brewster Co., , 20 mi. S Marathon, IV–12–1949 (Michener and Beamer). Dimmit Co., , Carrizo Springs, IV–14–1949 (Michener and Beamer). Maverick Co., , Quemado, IV–14–1949 (Michener and Beamer). Tom Green Co., , San Angelo, VIII–29–1924 (R. H. Painter). Uvalde Co., , VII–26–1933 (A. W. Linquist). Webb Co., , Laredo, V–20/24–1948 (W. Nutting). Zavala Co., , Crystal City, IV–14–1952 (Michener, Beamer, Wille, and LaBerge).

Utah: Iron Co., , Parowan, VII–25–1919.

Mexico: Baja California Sur, 10 mi. SW San Jose del Cabo, VII–9–1938 (Michelbacher and Ross); , “Canipole,” X–2–1941 (Ross and Bohart). Durango, , 15 mi. SW Pasaja, VIII–28–1929 (H. Smith). Sonora, , Guaymas, VII–2–1952 (S. C. Dorman); , Hermosillo, VIII–12–1959 (W. L. Nutting and F. C. Werner); , 35 mi. N Hermosillo, IV–26–1961 (R. H. and E. M. Painter); , , 75 mi. S Hermosillo, IV–25–1961 (R. H. and E. M. Painter). Tamaulipas, , 35 mi. S Matamoras, VIII–26–1954 (J. G. Chillcott); , Santander Jimenez, VII–19–1962 (N. Marston-6).

Additional specimens have been examined from Gila, Maricopa, Pima, Pinal, and Santa Cruz counties, Arizona; Los Angeles, Riverside, and San Diego counties, California; Hidalgo County, New Mexico; Lake County, Oregon; Dimmit and Sutton counties, Texas; and Baja California Sur and Durango, Mexico.

TYPES.—The holotype and allotype are deposited in the collection of R. H. Painter. Paratypes may be found in the collections of the author, R. H. Painter, Jack C. Hall, the University of Arizona, the Canadian National Collection, the University of Kansas, Utah State University, the Museum of Comparative Zoology, the University of California, the Academy of Natural Sciences of Philadelphia, the University of Michigan, Oregon State University, the California Academy of Sciences, and the U.S. National Museum.

BIOLOGY.—Two specimens were reared by Dr. K. V. Krombein (1967) from the nests of Megachile gentilis Cresson (Hymenoptera: Megachilidae).

Mexico (Baja California Sur, Coahuila, Durango, Sonora, Tamaulipas); USA (Arizona, California, New Mexico, Oregon, Texas, Utah).