Taxonomic review of New World Tachyina (Coleoptera, Carabidae): descriptions of new genera, subgenera, and species, with an updated key to the subtribe in the Americas Author Boyd, Olivia F. Author Erwin, Terry L. text ZooKeys 2016 626 87 123 http://dx.doi.org/10.3897/zookeys.626.10033 journal article http://dx.doi.org/10.3897/zookeys.626.10033 1313-2970-626-87 3DE781B6D48B432B97846703EA6B280B 3DE781B6D48B432B97846703EA6B280B Taxon classification Animalia Coleoptera Carabidae Genus Tachyxysta Boyd & Erwin gen. n. Type species. Tachyxysta howdenorum Boyd & Erwin, sp. n. Diagnosis. Pronotum with distinctly inflated basal section separated from pronotal disc by subsulcate transverse impression; basal section interrupted at midpoint by prominent, deep excavation opposite scutellum; overall form robust, convex. Description. Size. ABL = 2.4-2.5 mm; SBL = 2.5-2.7 mm; TW = 1.15-1.25 mm. Form . Compact, robust, convex. Color. Dorsally piceous, unicolorous (Fig. 2I); antennae and legs lighter, rufotestaceous except for darker basal half of coxae; dorsally glabrous and without microsculpture except for labrum. Head. Two pairs of supraorbital setae within channeled longitudinal frontal furrows; frons not raised between furrows, often with subtle transverse wrinkles (Fig. 3I); mentum without foveae. Prothorax. Base of pronotum (Fig. 3I) with deep lateral depression near posterior angle; posterior angle of pronotum raised, prominent; basal section of pronotum convex, interrupted by deep medial excavation opposite scutellum; male without dilated basal protarsomere(s); protibia notched apicolaterally (Fig. 2I); tarsal claws simple, not denticulate. Pterothorax.Elytral margin reflexed; i1 entire, subsulcate or faintly impressed; i2-i7 not visible; i8 striatiopunctate from humerus to Eo5, apically subsulcate (Fig. 4I); recurrent groove elongate, slightly sinuate, subparallel to elytral margin, and recurved anteriorly (Fig. 5I); surface without spots; elytral ombilicate setae 2, 6, and 8 more than twice as long as next longest seta. Genitalia. male aedeagus robust, elongate, with unequally sized, apically 3- or 4-setose parameres (Fig. 6E). Distribution. The Mexican specimens were collected near or in El Ocote Preserve; the Honduran specimen was collected in an area near Comayagua National Park. Based on collection data from a limited number of specimens, Tachyxysta howdenorum may be restricted to higher altitudes. Derivation of name. Feminine. Derived from Tachys , the nominate genus of the subtribe Tachyina , and the Greek xustos (= "smooth/polished" ), in reference to this species' unmicrosculptured, glabrous dorsal surface and alluding to its general resemblance to some members of the subtribe Xystosomina , particularly those of the genus Erwiniana .