Genus Macrolygistopterus Pic, 1929

Macrolygistopterus Pic, 1929:1. Kleine, 1933:104; Blackwelder, 1945: 351. Type species— Lycus succintus Latreille, 1811.

Differential diagnosis. The pronotum strongly sculptured, usually with a single longitudinal black, moderately wide stripe (except in M. succinctus, which is mostly black), the elytra with four well defined elytral costae, with traces of reticulate cells at the apex and subserrate antennae. Body medium to large sized.

Redescription. Body medium to large sized. Head prognathous, prolonged in rostrum, with visible longitudinal sulcus more or less prominent; integument from black to testaceous, sometimes intercalated, usually with a fine pubescence. Interocular distance 2 to 3 times the median width, the eyes sometimes touching the anterior margin of pronotum; maxillary palpus 4-segmented, with the last broader than the others; mandibles short, not or weakly curved, the tips distant when mandibles are closed, moderately connate to the labrum, the last always free. Antennae 11-segmented, subserrate, reaching middle of elytra; scape conic to subconic, other antennomeres dorsoventrally flattened, narrowing to the apex. Pronotum transverse to longer than wider, rectangular, subtrapezoidal or pentagonal, with longitudinal sulcus moderately deep, sculpturing variable.

Elytra rugged, lateral margins divergent, almost parallel-sided basally, from widened distally, with four welldeveloped elytral costae, costae I+II and III+IV merged at base in humeral region, of variable arrengement among the species; elytral reticulation variable, from strongly developed distally to vestigial or absent reticulation basally; color variable, metallic blue to green, reddish or testaceous, with the posterior half regularly black. Legs flattened, elongated, black to testaceous, finely pubescent; anterior coxa contiguous; meso and metacoxae aparted; protrochanters triangular and prominent; tibiae always with pair of spurs, spurs shorter in meso- and metatibiae.

Abdomen with seven visible ventrites in females and eight in males, in both sexes conspicuously lobed and pronounced angles; last ventrite of females of variable shape. Male genitalia with phallobase asymmetrical, parameres as long as aedeagus; aedeagus with apex acuminated or spoon shaped, slender. Female genitalia long, styli apically to subapically positioned, approximated, densely pubescent; coxites approximated at apex, both carrying setae; valvifers long and slender, at least 5 times longer than coxites, involved by membrane.

Distribution. Macrolygistopterus is a genus with 12 described species. They occur from the northern regions in Mexico, through the continental Central America to south of Brazil and northwest of Argentina (Figs. 45, 46).