Zyras Stephens, 1835: 430. Type species: Zyras haworthi (Stephens), established by decision of the International Commission on Zoological Nomenclature (ICZN 1961, Opinion 599)

Zyras Stephens: Cameron, 1939: 497 (key to subgenera and species of India, Myanmar and Sri Lanka); Kistner 1972: 143 (redescription); Scheerpeltz 1974: 39 (key to African subgenera); Seevers 1978: 153 (key to Nearctic species); Dvořák 1980 (key to species of Czech and Slovak Republic, including Pella, Lepla, Pellochromonia, Zyras, Myrmoecia); Dvořák 1984: 200 (key to Palaearctic species including China); Hastir and Gaspar 2001 (biology); Klimaszewski et al. 2005: 714 (restricted redefinition, key to species of America north of Mexico).

Diagnosis. Zyras (Zyras) can be distinguished from the other genera of Lomechusini by a combination of the following characters: 1) whole body shiny, unicoloured or often with different colouration for head, pronotum, elytra and abdomen, sometimes covered with long setae; 2) all antennomeres petiolate, antennomere III about as long as pedicel; 3) neck absent; 4) pronotum usually with well-defined median antebasal fovea; 5) abdomen simple, not physogastric, parallel-sided; 6) simplified aedeagus, median lobe with enlarged basal capsule and narrowly conical apical lobe; 7) spermatheca sclerotized, very small with narrowly elongate capsule and with extremely long and highly coiled spermathecal duct.

Description. Body (Fig. 1) slender, subparallel-sided. Body length highly variable, ranging from 3–9 mm, whole body always shiny, unicoloured, or often with different colouration for head, pronotum, elytra and abdomen.

Head (Figs 2, 3) slightly wider than long, posterior margin slightly covered by anterior edge of pronotum, neck absent; temples long, round, about as long as diameter of eyes or longer; occipital suture present, not visible dorsally, ventrally reaching hypostoma, hypostoma narrow; surface with erect or appressed setae. Gula long, evenly divergent from anterior to posterior; submentum fused to gula, broadly expanded anteriorly. Eyes large, oval in lateral view, prominent.

Antennae (Fig. 4) with all antennomeres petiolate, antennomere III about as long as II, when bent backwards slightly exceeding base of pronotum.

Labrum (Fig. 5) much wider than long, with shallow median excavation; surface covered with numerous pseudopores and about ten real pores, except on posterior and lateral areas; antero-lateral areas each with 4–6 macrosetae of different length.

Mandibles (Figs 6–9) almost symmetrical, lacking teeth, with 3–4 small setae present dorsally, mesal areas of dorsal and ventral surfaces covered with numerous pseudopores, prostheca with inner margin pubescent.

Maxilla (Fig. 10) is generalized in shape like for other Lomechusini, with elongate galea and shortened lacinia, palpomere I minuscule, palpomere II slightly curved and gently short- er that palpomere III, terminal palpomere about three times as short as III, pointed apically.

Figure I. Zyras (Zyras) haworthi (Stephens), dorsal view (approximative length of photograped specimen is 7.1 mm)

Mentum (Fig. 11) trapeziform, posterior and anterior margins truncate, with setae, surface covered with pseudopores bearing minute setae, and about 6–8 pores with longer setae present on antero-lateral areas.

Labium (Fig. 12) with prementum with two real pores and one setal pore mesolaterally, with about 30–40 pseudopores behind medial setae, apodeme with large, truncate process, lateral lobes of apodeme gently curved, assimetrical, bifurcate apicaly. Ligula bilobed, each lobe long, pointed apically, with fine apical seta. Labial palpus with first segment long, more than twice as long as second and clearly thicker, third segment slightly longer than second and about twice as slender as second.

Pronotum slightly wider than long (Fig. 1), anterior margin straight, posterior margin evenly rounded, posterior corners small but well-defined, smooth or entirely or