A revision of the genus Zyras (Zyras) Stephens, 1835 (Coleoptera, Staphylinidae, Aleocharinae). I. Current classification status and the redefinition of the genus

Th e genus Zyras is redefi ned and redescribed based on the study of the type species Zyras haworthi (Stephens). Illustrations of all important morphological characters are provided. Th e status of the genus Zyras (s.l.) is discussed. A list of all species attributed to the subgenus Z. (Zyras), including the species described as Zyras (s.str.), is also given.


Introduction
Th e Lomechusine genus Zyras Stephens, with currently 802 species and 54 subgenera (Hlaváč, Newton and Maruyama, in prep.), is certainly one of the largest and most problematic genera of the subfamily Aleocharinae.All species of the genus are believed to be free predators (synechtrans) of various species of ants.Th e taxonomic chaos in this genus is manifested by the fact that 122 species were described only as Zyras without any affi lation to a subgenus.Another 68 species originaly described as Zyras were subsequently synonymyzed or transferred to diff erent genera.
As a consequence of these changes, the following 52 subgenera of the genus Zyras have remained valid (Hlaváč, Newton and Maruyama, in prep.)Last, Synthoracodonia Scheerpeltz, Taprodonia Cameron, Termidonia Motschulsky, Termitelia Cameron, Termitodonia Cameron, Trigonodonia Bernhauer, Trigonozyras Cameron, Tropidonia Bernhauer, Visendor Last.Th e logical question must be "Is it really possible that all these very numerous taxa, distributed worldwide, form a monophyletic group?"Th is question is not new and it has already been raised twice, fi rst by Seevers (1965: 238) ["Th e taxonomic state of the vast Zyras complex is one of great confusion and the proposal of more than 50 subgenera has not helped clarify matters very much"] and later by Kistner (1972: 148) ["Also each species alleged to Zyras (s. str.) in the literature will need to be checked before its inclusion in the redefi ned genus is settled.For example, I have not seen a species from sub-Saharan Africa which really belongs to this genus.It is highly likely that Zyras in the future will be a very small genus"].We fully agree with these two opinions, except for the number of species of true Zyras, which is anticipated to grow to at least 200 species.
Th e distribution of the genus seems to be mainly in the holarctic region with only three species in the USA and Canada (Klimaszewski et al. 2005), fi ve species in the western Palaearctic region and a large number of species in eastern Palaearctic, Oriental and perhaps also in the Australian regions.We have not seen, like Kistner (1972), any true Zyras from sub-Saharan Africa or from America south of USA.Of six species of Zyras reported by Ashe (Navarrete-Heredia et al. 2002) from Mexico, two species already have been transferred to another genus, Pella fauveli (Sharp) and Myrmoecia tapinomatis Mann (Klimaszewski et al. 2005).Th e remaining four species should be checked, but they, highly likely, will not be members of true Zyras either.
We are sure that many, if not all, species currently attributed to diff erent subgenera of Zyras, have nothing or very little in common with the true Zyras.For the subgenera Diaulaconia (Hlaváč 2005: 153) and Glossacantha (Hlaváč 2005;Maruyama 2006, respectivelly) that has been already discussed, although the new status of both genera has not been offi cially changed.In our opinion, Zyras is a very characteristic and well defi ned genus, and any further fragmentation should be carefully re-considered.

Material and methods
Th e main goal of this article is to redefi ne the genus Zyras based on its type-species, Zyras haworthi (Stephens).Th e material used for this study was taken from some institutions listed below.
Specimens prepared for the morphological study were examined with Leica S8A-PO stereo-microscope and Nikon SMZ -1B stereo-microscope with diff use lighting at magnifi cations up to 105×.Male genitalia and other dissected parts were studied using a Meopta transmitted-light microscope at magnifi cation up to 450×.Genital segments were dissected and treated with lactic acid.All drawings were made using a drawing tube.Th e dissected and mounted parts were mounted and pinned with the specimen.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 diff erent 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-defi ned median antebasal fovea; 5) abdomen simple, not physogastric, parallel-sided; 6) simplifi ed 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 diff erent colouration for head, pronotum, elytra and abdomen.

Depository abbrevations
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 diff erent length.
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 shorter that palpomere III, terminal palpomere about three times as short as III, pointed apically.
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 fi ne apical seta.Labial palpus with fi rst 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-defi ned, smooth or entirely or partially coarsely punctured and sparsely covered with erect long setae, macrosetae on lateral margins present, well-defi ned, median antebasal fovea usually present (may be missing in some species, for instance Z. bakerianus).Elytra subparallel-sided (Fig. 1) with well-defi ned sutural groove throughout, combined width of elytra about twice as wide as long on suture, sutural striae well-defi ned through whole length.Scutellum triangular.
Abdomen simple, not physogastric, parallel-sided, at base with punctures and with long setae on side; paratergites well-developed on tergites III-VII; tergites with posterior margin straight; sternite with surface moderately to densely covered with setae; eighth abdominal segment (Figs [15][16][17][18] species characteristic and also bearing sexual characters; tergite VIII (Figs 15,17) narrowed posteriad, truncate apically, apex crenate or dentate, sternite VIII (Figs 16,18) narrowed posteriad, at apex rounded in male and truncate in female, apical setae in female longer and thicker than in male.Ninth tergite as in (Figs 19,20), lateral lobes in male asymmetric, absent in female as in most Aleocharines (Maruyama 2006).Ninth sternite of male as in (Figs 21, 22) elongate, somewhat pointed at base, expanded apicad and truncate at apex, with well-defi ned sharp corners, oblong in middle, bearing setae which are longer and dense on sides.
Head 1.15 times as wide as long, on sides with long erect golden setae.Antennae (Fig. 4) with scape almost twice as long as pedicel, pedicel slightly longer than antennomere III, antennomeres IV-VII about the same length, IV-VI slightly transverse, antennomeres VII-X rhombic, clearly extended apicad, X shortest, terminal antennomere about as long as antennomere III, almost twice as long as wide at base, round at apex.
Pronotum (Fig. 1) 1.25 times as wide as long and 1.28 times as long as head, irregularly punctured, setose and with about fi ve long black macrosetae on each side.
Mesoventrite (Fig. 14) regularly, coarsely punctured on the whole surface.Metaventrite 1.5 times as wide as long and 3.5 times as long as mesoventrite (measured in mid line), smooth in the middle, coarsely punctured on sides, here also with erect golden setae.
Abdomen two-coloured, densely punctured apex of visible tergites III-V dark reddish-brown, base much lighter and bearing setae, tergites VI-VII dark reddish-brown almost on the whole surface, densely punctured at base and with few but long apical setae, paratergite III-VII well defi ned covered with setae, paratergites III-V punctured.
Sexual dimorphism: females have diff erent structure of abdominal tergites and sternites VIII,.Tergite VIII with small median tubercle in male, tubercle lacking in female, truncate apex is much narrover in male than in female, median excavation deeper in male than in female; sternite VIII round in male, truncate in female; tergite IX with asymmetric lateral lobes in male, lateral lobes lacking in female.

Checklist of species of the subgenus Zyras (Zyras) (Stephens)
A detailed world catalogue of the tribe Lomechusini is near completion (Hlaváč, Newton and Maruyama, in. prep.).Th e purpose of this checklist is to provide a listing of all species which were described as, or placed subsequently in the subgenus Zyras (Zyras), or Zyras (s.str.).All species described as Zyras without subgeneric affi lation are excluded from this list.Th e list is arranged by zoogeographical regions.Th is division is a practical solution for the better orientation within the genus.

Nearctic region:
Th is area includes America north of Mexico, i.e.USA and Canada.All three species listed here are true Zyras and were revised recently (Klimaszewski et al. 2005).

1.
obliquus (Casey, 1894: 325)  Th is area includes Siberia east from Lake Baikal, Nepal, northern India, China, Taiwan, Koreas, Japan and Russia Far East.Currently there are 36 species described from this region and one nomen nudum.

Neotropical region:
Mexico, Central and South America (including Caribbean islands).Th ere are two species from this vast area known today.We believe that true Zyras do not occur in Neotropics and both species probably belong to other genera of Lomechusini.Bierig, 1937: 281.Distribution: Cuba 114.paecesanus Pace, 1997: 36. Distribution: Colombia
Th is area, as defi ned here, includes the whole of Europe, northern Africa, Arabian peninsula, Caspian region and Siberia to Lake Baikal.All fi ve species recorded here are true Zyras.