Metachroma longulum Horn 1892

Metachroma longulum Horn

Metachroma longulum Horn, 1892, p. 212.

Metachroma novemstriatum Schaeffer, 1919, p. 328.

Metachroma opacipenne Fall, 1927, p. 138.

DESCRIPTION.—From 3.4 to 4.7 mm in length, elongate oblong oval, shining, prothorax unusually convex, deep reddish brown usually with darker areas on each side, distinctly and densely punctate, elytra somewhat paler yellowish or reddish brown usually with from two to four reddish brown or piceous spots sometimes coalescing to form a dark vitta or widening to join suture, sutural edges often dark, striate punctures deeply impressed with somewhat costate intervals, especially on sides.

Head with interocular space approximately half width of head, base of occiput punctate, front sometimes nearly smooth but often coarsely and densely punctate, shining, front not separated from clypeus by transverse groove, clypeus usually more densely punctate, anterior margin with small emargination over labrum; a faint median line down front; yellowish or reddish brown with darker jaws. Antennae pale yellow or reddish brown, extending below humeri. Prothorax unusually convex, with slightly rounded sides, about a third wider than long, shining deep reddish brown, usually with darker brown or piceous area on each side, densely and often coarsely punctate, punctures on sides being denser and coarser and often with a median impunctate line. Scutellum dark reddish brown. Elytra a little more than twice as long as prothorax and not much wider, shining, sometimes without spots but usually paler than prothorax with, on each elytron, two deep brown or piceous median spots (one before and one after the middle) or sometimes only one spot, and occasionally in darker specimens spots coalesce to form a short median vitta and sometimes a wide dark area covering most of elytra, usually sutural edges dark. Striate punctures deeply impressed in basal half and on sides, making intervals appear costate. Body beneath reddish brown or piceous, legs paler, hind femora with minute tooth; claws appear simple. Length, 3.4–4.7 mm; width, 1.5–2.5 mm.

TYPE.—Of longulum Horn in Horn collection, PAS; of novemstriatum Schaeffer in USNM; of opacipenne Fall in Fall collection, MCZ.

TYPE-LOCALITIES.—Arizona (longulum Horn); Lower California (novemstriatum Schaeffer); Santa Rosa, Lower California (opacipenne Fall).

OTHER LOCALITIES.—Texas: El Paso. Arizona: Gila Bend, Wickham; Winslow, Barber and Schwarz; Gillespie Dam, E. P. Van Duzee, F. Werner, W. Nutting; Holbrook, F. H. Parker; Tucson, R. A. Flock; Gila Valley, F. H. Parker. Colorado: La Junta. Wyoming: Rock Spring, O. Bryant. Lower California: San Domingo; Mesquital; 20 miles south of Coyote Cave, Conception Bay, 10 miles south of Catavina, and 12 miles south of Santa Rosalia, all collected by Michelbacher and Ross. Mexico: Desemboque, Sonora, B. Malkin.