Zopherus tristis Le Conte 1851

Zopherus tristis LeConte

Zopherus tristis LeConte, 1851:130.—Horn, 1867:161; 1870:272;1894:347.

Zopherodes tristis, Casey, 1907a: 38.—Blaisdell, 1923:243; 1931:113.

Zopherodes aequalis Casey, 1907a:38 [new synonymy].

Zopherodes variabilis Casey, 1907b:464 [new synonymy].

Zopherodes incrustans Casey, 1907b: 464 [new synonymy].

This is one of the easiest species of Zopherus to recognize, but one of the most difficult to characterize. The body is subcylindrical, greatly thickened dorsoventrally, with the elytral margins parallel throughout a greater portion of their length and abruptly constricted at the base and apex. The apical declivity is more abrupt and steeper than in any other species. The elytral tubercles are usually rather flattened with their hind margins somewhat truncate. Most specimens have the pronotum coarsely punctured, but several have coarsely granulate punctures as in granicollis; the prosternum is coarsely punctured. Sometimes the flanks of the pronotum and elytra are encrusted with a whitish substance, and this may frequently be restored by soaking the specimen in ether. It appears to be of no taxonomic significance.

Casey (1907b:467) considered regarding the species he named aequalis, incrustans, and variabilis as subspecies of tristis. I have examined the types and they all fall well within the range of variation exhibited by tristis.

MEASUREMENTS.—Length 10.5–22 mm; width 3.9–7.6 mm.

TYPES.—Zopherus tristis LeConte (not seen). Type locality: “in deserta fluminis Colorado.” Zopherodes aequalis Casey. Holotype (USNM 46350). Arizona (Gila Valley), Dunn. Zopherodes variabilis Casey. I have selected and so labeled the first of six specimens under this name in the Casey collection as lectotype. All were collected in the Baboquivari Mountains, Arizona, by F. H. Snow and bear a USNM type number 46351. This series is quite variable in size and sculpture, but one of them (the third) is a perfect match for the type specimen of aequalis Casey. Zopherodes incrustans Casey. Holotype (USNM 46349). Tucson, Arizona, F. H. Snow.

SPECIMENS EXAMINED.—276 from the localities that follow. UNITED STATES. ARIZONA: Ajo, Baboquivari Mountains, Buckeye, Bumble Bee, Chandler, Florence, Granite Reef, Mesa, Nogales, Organ Pipe Cactus National Monument, Parker, Phoenix, Prescott, Riverside, Safford, San Carlos Lake, Santa Catalina Mountains, Tacna, Tempe, Tucson, Vail, Wellton, 12 miles east of Wenden, Wickenburg, Yuma. CALIFORNIA: Blythe, Borrego, Calexico, Caliente, Coachella Valley, Carrizo Springs, Holtville, Imperial, Indio, Laguna, Palm Springs, Palo Verde, Thermal, Winterhaven, Yuma. TEXAS: One specimen with State label only, probably in error. MEXICO. BAJA CALIFORNIA: Comondu, Loreto, Mulege, 1 mile south of Puerto Escondido, 10 miles south of Punta Prieta, San Domingo, 5 miles south of San Miguel, 25 miles south of Santa Rosalia. SONORA: Guaymas, Hermosillo, Pesqueria. Specimens have been collected in every month except December.

Zopherus tristis is a species of ironclad beetle in the family Zopheridae. It is found in Central America and North America.