Zapotecanillus, Sokolov, Igor M., 2013

Sokolov, Igor M., 2013, A new genus and eight new species of the subtribe Anillina (Carabidae, Trechinae, Bembidiini) from Mexico, with a cladistic analysis and some notes on the evolution of the genus, ZooKeys 352, pp. 51-92 : 54-57

Zapotecanillus gen. n.

Type species.

Zapotecanillus oaxacanus sp. n., by present designation.

Etymology.

The name Zapotecanillus derives from the Zapotecs, the name of the indigenous people living in the territory of Oaxaca during historic times, and the generic name Anillus Jacquelin du Val, the type genus of the subtribe.

Recognition.

The members of this genus are distinguished from the other North and Central American representatives of Anillina by the following combination of characters: frontal area of head flat, without a median tubercle; maxillary palps with palpomere 4 longer than 1/3 of palpomere 3; labium with glossal sclerite with short but distinct paraglossae, and with mentum and submentum fused, without mental-submental suture; pronotum forward of the lateral seta and towards anterior angles with a row of elongate setae; elytra without fixed discal setae and with 8th and 9th pores of umbilicate series much closer to each other than the 7th pore is to the 8th (i.e. the “geminate” condition). The most distinctive features of the representatives of the new genus, easily distinguishing them from the species of Geocharidius , are the presence of elongate setae at the anterior angles of pronotum forward of the lateral pronotal setae (cf. Fig. 1 versus Fig. 2), a longer maxillary palpomere 4 (cf. Fig. 5 versus Fig. 6), the absence of suture between the mentum and the submentum (cf. Fig. 7 versus Fig. 8), the “geminate” state of the 8th and 9th pores of umbilicate series (cf. Fig. 3 versus Fig. 4), the cross-shaped metendoventrite and the truncate intercoxal process between the hind legs (cf. Fig. 13 versus Fig. 14).

Description.

Size. SBL range 1.01-1.55 mm.

Habitus. Body form weakly to moderately convex, ovoid or subparallel (Figs 24-31).

Color. Body bicolored (Fig. 24) or monocolorous (Figs 25-31), brunneorufous, rufotestaceous or testaceous, appendages testaceous.

Microsculpture. Dorsal microsculpture of polygonal sculpticells on head, pronotum and elytra. Mesh pattern varies on different body parts. On head, sculpticells transverse, 2-3 times wider than long (Fig. 5). On pronotum, sculpticells longer, 1.5-2 times wider than long. On elytra, sculpticells form mostly isodiametric mesh pattern. Development of microsculpture on pronotum varied among different species.

Luster. Body surface shiny.

Macrosculpture. Body surface sparsely and finely punctate.

Vestiture. Body surface covered with sparse yellow setae of moderate length. Anterior angles of pronotum bear several long setae laterally, which are two times longer than adjacent vestiture (Fig. 1, als).

Fixed setae. Primary head setae include a pair of clypeal (cs), a pair of frontal (fs) and two pairs of supraorbital (ass and pss) setae (Fig. 5). Mentum with three pairs of long primary (medial, paramedial and lateral) setae (Fig. 11, mms, pms, lms). Medial mental setae located on mental tooth, not near its base on mentum (Fig. 7, mms). Submentum with two pairs of long primary setae in two rows (lss1, prss) and 1 additional pair of shorter setae (lss2) located laterally (Fig. 11). Maxilla with long stipetal and palpiferal setae (Fig. 12). Pronotum with two long primary lateral setae (middle, ls, and basal, bs) on each side (Fig. 1). Elytra lack discal setae (Fig. 3), but with scutellar (ed2) and apical (ed8) setae. Last two (8th and 9th) pores (eo8 and eo9) of umbilicate series much closer to each other than 7th (eo7) pore is to 8th (Fig. 3). Fifth visible sternite of male with two and of female with four setae along the posterior margin.

Head. Anterior margin of clypeus (cl) straight (Fig. 5). Frontal area flat without tubercle (ft) medially near frontoclypeal suture. Fronto-lateral carinae distinct and long.

Eyes. Eyes absent.

Antennae. Submoniliform, 11-segmented, extended to about posterior margin of pronotum. Antennomeres 1 and 2 elongate, of equal length and 1.4-1.5 times longer than antennomere 3, which is only slightly elongate and 1.1-1.2 times longer than antennomere 4. Antennomeres 4 to 10 globose, last antennomere (11) conical and 1.6-1.8 times longer than penultimate antennomere.

Labrum. Labrum (l) transverse with straight, entire anterior margin with six setae apically, increasing in size from the central pair outwards (Fig. 5).

Mandibles. General plan of Bembidion type ( Maddison 1993). Right mandible with distinct anterior (art) and posterior retinacular (prt), terebral (tt), premolar (pm) and molar (m) teeth (Fig. 10). Left mandible with distinct terebral (tt), posterior retinacular (prt), premolar (pm) and molar (m) teeth only (Fig. 9).

Maxillae. Maxillary palps (Fig. 12) similar to Bembidion ( Maddison 1993) with basal trianguloid cardo, and stipes with dorsal and ventral lobes (dls, vls), dimerous galea (g1, g2), and standard lacinia (lc), with subulate palpomere 4 (mp4). Palpus (Fig. 5) with long 4th palpomere (mp4), 0.4-0.5 length of palpomere 3 (mp3).

Labium. Labium (Fig. 7) with mental tooth; mentum and submentum fused, without mental-submental suture (ms) and with moderately enlarged lateral mental lobes, which are translucent along the lateral margins (llm). Glossal sclerite (gsc) with short but distinct paraglossae (pg) laterally and with two setae apically. Central area of mental-submental complex with a field of pores and 1-2 pairs of shorter setae additionally (Fig. 11).

Prothorax. Pronotum cordiform, moderately convex, not sinuate (Figs 32-33) or slightly sinuate posteriorly (Figs 34-35). Basal margin of pronotum either straight (Fig. 32), or oblique laterally (Figs 33-34), in one species bisinuate laterally, at posterior angles (Fig. 35). Anterior angles indistinct, broadly rounded. Posterior angles denticulate, without or with 1-2 small denticles in front of the angles. Widths across anterior margin and between posterior angles of approximately equal length (WPa/WPp varies from 0.96 to 1.04 among species).

Scutellum. Externally visible, triangular, with narrowly rounded apex.

Elytra. Elytra of moderate length (LE/SBL from 0.57 to 0.58 among species) without visible interneurs (Fig. 3). Humeri rounded to form right angle with longitudinal axis of body. Basal margination (bm) distinct and long, reaches half the distance between humeral angle and scutellar pore (Fig. 1). Apical half of elytra with shallow but evident subapical sinuation (ss) (Fig. 3).

Hind wings. Absent.

Pterothorax (Fig. 13). Metaventrite (mtv) short, distance between meso- and metacoxae about of the diameter of mesocoxa. Metanepisternum (mte) short, subquadrate, with anterior and outer margins of equal length. Metendoventrite (mes) cross-shaped with long lateral arms.

Legs. Legs of moderate length, not elongate. Prothoracic legs of males variable in structure of tarsomere 1. Typically, 1st protarsomere markedly dilated apico-laterally with two rows of oval articulo-setae ( Stork 1980) on the ventral surface (Figs 20-21). Some species with 1st tarsomere only slightly dilated and with only one (outer) row of oblong articulo-setae (Fig. 22), and other species with 1st tarsomere non-dilated and without adhesive vestiture (Fig. 23). Protibiae (Figs 15, 17-19) with antenna cleaner of type B ( Hlavac 1971), with both anterior (asr) and posterior (psr) apical setal rows and concave apico-lateral notch (Fig. 18, tbn). Profemora moderately swollen. Mesotibiae with two terminal spurs and tibial brush. Metafemora unmodified, metatibiae with two terminal spurs. Tarsi pentamerous, 5th and 1st tarsomeres are the longest, 2-4 tarsomeres of equal length on the tarsi of all legs, 1st tarsomere shorter than combined length of 2-4 tarsomeres (Fig. 15). Tarsal claws simple, untoothed (Fig. 16).

Abdominal ventrites. Five visible abdominal ventrites: 2nd ventrite longest (Fig. 13), more than 3 times longer than 3rd or 4th, 3rd and 4th equal in length; the last, 5th, approximately 1.5 times longer than 4th. Intercoxal process (ipa) of 2nd ventrite broad, truncate anteriorly (Fig. 13).

Male genitalia (Figs 36-59). Median lobe of aedeagus anopic, elongate, twisted and slightly arcuate. Internal sac with two groups of copulatory sclerites: dorsal group represented by 2 plates, and ventral group represented by weakly sclerotized fold or folds. Dorsal plate 1 (dp1) in form of an elongate plate, rounded or pointed at basal end, and tapered into a needle-like structure apically. Dorsal plate 2 (dp2) much smaller than plate 1, also needle-attenuated apically, curved and enlarged towards base; coplanarly adjoined to dorsal plate 1 apically in lateral view and divergent from plate 1 basally as a ventrally directed protuberance; can be seen as a separate structure in some species (Figs 54, 57). Ventral sclerites (vsc) of varied shape, dependent on development of sclerotization. Additional spines or scaled membranous fields of internal sac are absent. Parameres typically bisetose, except right paramere of Zapotecanillus pecki 3-setose (Fig. 53). Left paramere large and broad, either evenly tapered to apex (Figs 43, 46) or with short attenuation before setal attachment (Figs 37, 40). Ring sclerite broadly ovate with transverse handle-like extension of varied length and shape (Figs 60-67, hd).

Female genitalia (Figs 68-76). Ovipositor sclerites: Gonocoxite 1 asetose (gc1). Gonocoxite 2 triangular (gc2), 1.6-1.8 times longer than its basal width, slightly to moderately curved, with 2 lateral ensiform (es) and apical nematiform (ns) setae. Laterotergite (lt) with 5-8 setae. Internal genitalia with spermatheca sclerotized, rufous, spherical and ball-shaped in most species, fusiform with a bulb-like enlargement apically in Zapotecanillus kavanaughi (Fig. 75).

Included taxa.

The new genus includes eight species: Zapotecanillus oaxacanus sp. n., Zapotecanillus nanus sp. n., Zapotecanillus ixtlanus sp. n., Zapotecanillus iviei sp. n., Zapotecanillus montanus sp. n., Zapotecanillus pecki sp. n., Zapotecanillus kavanaughi sp. n., and Zapotecanillus longinoi sp. n.

Geographical distribution.

The species of this genus are known from three mountain ranges of Mexico: the Sierra Madre de Oaxaca, the Sierra Madre del Sur and the Sierra Madre de Chiapas, within the states of Oaxaca and Chiapas (Fig. 77). This type of distribution best fits Halffter’s (1987) Meso-American Montane Distribution Pattern.

Way of life.

According to the label information, specimens of the new genus were taken from the leaf litter within the 1200-3000m range of altitudes at the Sierra Madre de Oaxaca, and in mesophyll and cloud forests within the 1330-2140m range of altitudes at the Sierra Madre de Chiapas. Collecting dates are May, June, July and August. One specimen from the Sierra Madre de Oaxaca was taken "under bark hardwood".

Relationships.

The position of Zapotecanillus within the North and Central American Anillina is unclear at present, and awaits molecular data analysis or further discoveries and subsequent morphological analyses of the Middle American anilline taxa. Members of this new genus differ principally from those of the southern stock of Middle American anilline genera ( Geocharidius Jeannel, Honduranillus Zaballos, Mexanillus Vigna Taglianti) in having a different arrangement of the last three pores of the umbilicate series and the fused labium, and from geographically proximate Geocharidius and Mexanillus in having distinct paraglossae. They differ from members of the northern stock of North American anilline genera ( Anillaspis Casey, Anillinus Casey, Anillodes Jeannel, Micranillodes Jeannel, Serranillus Barr) in lacking fixed discal pores on the elytra.

The key provided below allows distinguishing members of the new genus from those of the other continental North and Middle American anilline genera: