Cremastocheilus planipes

One of about thirty-five species of myrmecophilous Cremastocheilus. The host ant is Novomessor cockerelli.

Key to Trinodia species
(Horn, 1885) The punctures of the entire surface bear short erect black hairs. The mentum is rather flat at bottom, the sides reflexed, the posterior angle entire.

Distribution
Arizona (type locality), New Mexico, Texas; Mexico (Chihuahua, Puerto de Janos)

Habitat
Common host is Novomessor cockerelli.

Description
(Horn, 1885) Robust, piceous, feebly shining, legs reddish brown. Head coarsely, not densely punctate, occipital region transversely depressed, clypeus semi-circular, margin widely reflexed and fimbriate with short hairs, at middle strongly carinate, surface smooth. Thorax transverse, narrower behind, sides slightly arcuate in front, oblique behind, hind angles acute, smooth and shining, anterior angles deeply incised forming an auriculate lobe, disc trilobbed, the median portion much wider and depressed, surface with rather closely placed variolate foveae, densely placed near the side margin. Disc of elytra flat, with very elongate foveae, sides nearly vertical with coarse variolate punctures. Pygidium with coarse variolalte punctures. Body beneath coarsely sparsely punctured. Legs broad and flat, sparsely punctured on the under side, smooth above. Anterior tibiae bidentate at apex, middle and posterior tibiae with the outer edge acutely bidentate near the tip. Tarsi cylindrical, slightly compressed, shorter than the tibiae. Length .52 inch; 13 mm. (Pl.4, fig. 2.)