Triplax wehrlei

Adults of this beetle are about 2.3-4.6 mm long and 1.25-2.3 mm wide, with an elongated elliptical body; in 42 specimens it was noted that the southern (Mexican) specimens were at most 4 mm long and 2 mm wide, while the northern (Arizona) ones were all distinctly larger; since only 3 northern beetles were studied, and all the Mexican ones were from a single region or even collection, this may be just a coincidence. Unlike most of its relatives, the carapace of T.wehrlei is markedly hairy, covered with fine fuzz except on the wings and legs, and quite notably so on the abdomen where the hair is stronger and longer as is usual in Triplax. Like in many of their relatives, head and pronotum are reddish-orange, while the elytra are black and (due to the hair) barely shiny. As usual for the members of the "breast-plated" species complex, T.wehrlei has orange legs and antenna bases and lacks a conspicuous margin to the forehead sides, which also form a well-rounded obtuse angle towards the tip. The "stems" of the antennae are orange to segment 6, turning to black in the "club" at the end of the antennae; the scutellum is blackish-brown. The underside is reddish-orange, in some individuals with blackened episterna of the metathorax. …

T.wehrlei is a little-known species with a potentially wide range in the northern Neotropics. The type specimen is a male, collected on July 9, 1930, at Patagonia, Arizona, by J.O.Martin. Additional United States records are from the Pinal and Santa Rita Mountains. The species has also been reported from Mexico, where it might range at least to the Isthmus of Tehuantepec and has been found in considerable numbers in Morelos State. Its ecology is barely known; dated specimens are from June and July, when Triplax are most abundantly encountered. It might range up to altitudes of 7,000 ft or more (over 2,000 m) AMSL, but the type locality is only at about 4,000 ft (1,200 m). While it seems to occur on some of the "sky island" mountains that rise at the boundary of the Chihuahuan and Sonoran Desert, catching moisture and growing a northernly extension of the Sierra Madre Occidental pine–oak forests of Mexico, it is not strictly associated with upland forest; Morelos State is entirely in the Balsas Dry Forests ecoregion. …