Vaejovis nigrescens, Pocock, 1898

Soleglad, Michael E. & Fet, Victor, 2008, Contributions to scorpion systematics. III. Subfamilies Smeringurinae and Syntropinae (Scorpiones: Vaejovidae), Euscorpius 71 (71), pp. 1-115 : 102-104

“nigrescens ” group:

V. curvidigitus Sissom, 1991

V. davidi Soleglad et Fet, 2005

V. decipiens Hoffmann, 1931

V. gracilis Gertsch et Soleglad, 1972 V. intermedius Borelli, 1915

V. janssi Williams, 1980

V. mauryi Capes, 2001

V. mitchelli Sissom, 1991

V. nigrescens Pocock, 1898

V. norteno Sissom et González Santillán, 2004 V. pococki Sissom, 1991

V. solegladi Sissom, 1991

Distribution. Mexico (Aguascalientes, Chihuahua, Coahuila, Distrito Federal, Durango, Guanajuato, Guerrero, Hidalgo, Jalisco, Mexico, Michoacán, Nuevo León, Oaxaca, Puebla, Querétaro, San Luis Potosí, Sonora, Veracruz, Zacatecas), USA (Texas).

The range of the “nigrescens ” group of Vaejovis exhibits four disjunct parts (see map in Fig. 205 ): V. janssi is found on the tiny Isla Socorro in the Pacific Ocean, V. mauryi in central Sonora, V. gracilis in Veracruz, and the majority of species found from as far north as Texas, Chihuahua, Coahuila, and Durango ( V. intermedius ) to Oaxaca ( V. solegladi ).

Taxonomic history. The nominotypic genus Vaejovis has been an “umbrella name” for many vaejovid taxa for well over 100 years (just like Buthus for Buthidae ). Most notably, genera Pseudouroctonus Stahnke, 1974 and Serradigitus Stahnke, 1974 have been separated from Vaejovis ; and, more recently, Franckeus Soleglad et Fet, 2005 and Gertschius Graham et Soleglad, 2007 . The genus Vaejovis is further reduced here as a result of current revision, as we establish four new genera, Hoffmannius , Kochius , Thorellius , and Wernerius , which absorb the species from informal “ eusthenura ,” “intrepidus ,” “punctipalpi ,” and “spicatus ” groups of Vaejovis .

Key to subfamilies, tribes, subtribes,

and genera of family Vaejovidae

1. Genital operculum sclerites of female operate separately, divided on posterior two-fifths to one-half, not connected to mesosoma on extreme distal aspect but more midpoint; chelal trichobothria ib–it positioned proximal to basal inner denticle (ID), but usually not on finger base; chelal trichobothria V 2 –V 3 distance approximately twice as great as V 1 –V 2; fixed finger trichobothria dsb and dst positioned proximal of esb and est, respectively; leg tarsus with one pair of ventral distal spinules; setal combs present on legs; number of constellation array sensilla 2–3; serrula vestigial to weakly developed with non-continguous tines; dorsal carinal terminus of metasomal segments I–III rounded, not terminating with an enlarged denticle; dorsolateral carinae of metasomal segment IV not conspicuously flared at the terminus, essentially coinciding with articulation condyle; median eye tubercle and eyes enlarged, 21–30 (27.6) % as wide as carapace at that point. ... (subfamily Smeringurinae , subfam. nov.) ... 2 • Genital operculum sclerites of female operate as a single unit, either connected their entire length or divided on posterior one to two-fifths, connected to mesosoma on distal quarter; chelal trichobothria ib–it position variable, from base of fixed finger to finger midpoint; chelal trichobothria V 2 –V 3 distance approximately same as V 1 –V 2; fixed finger trichobothria dsb and dst positioned adjacent to or distal of esb and est, respectively; leg tarsus with 1–4 pairs of ventral distal spinules; setal combs absent on legs; number of constellation array sensilla 3–7; serrula medium to highly developed; dorsal carinal terminus of metasomal segments I–III flared, terminating with an enlarged denticle; dorsolateral carinae of metasomal segment IV conspicuously flared at the terminus, not coinciding with articulation condyle; median eye tubercle and eyes not enlarged, 12–23 (19.0) % as wide as carapace at that point. ………………………………………………..… 5

2. Hemispermatophore lamellar hook minimal, not extending beyond ventral trough, basal constriction essentially absent; mating plug barb smooth; chelal trichobothrium Dt positioned quite proximal of palm midpoint; femoral trichobothrium d proximal to i, and e positioned proximally on segment; major neobothriotaxy absent on ventral aspect of palm; number of constellation array sensilla usually 2; chelicerae with denticles on the ventral edge of the movable finger, and protuberances usually found on the ventral aspect of fixed finger; vesicular tabs variable, either well developed with hooked spine, or reduced and rounded.……. ……. (tribe Smeringurini , trib. nov.) ………………. 3 • Hemispermatophore lamellar hook well developed, extending well beyond the ventral trough, exaggerated by conspicuous basal constriction; mating plug barb toothed (after Stockwell, 1989); chelal trichobothrium Dt positioned distal of palm midpoint; femoral trichobothrium d distal to i, and e positioned near midsegment; major neobothriotaxy present on ventral aspect of palm; number of constellation array sensilla 3; chelicerae without denticles on the ventral edge of the movable finger or protuberances on the ventral aspect of fixed finger; vesicular tabs reduced and rounded, distal granule vestigial to obsolete in adults. ………….… (tribe Paravaejovini , trib. nov.).… genus Paravaejovis 3. Two ventromedian (VM) carinae present on metasomal segments I – IV; hemispermatophore lamina terminus with squared or rounded distal tip, inner base of lamina lacking small protuberance; ungues of legs not elongated or highly asymmetric; ventral aspect of leg tarsus surface lacking a cluster of elongated curved setae; dorsal carinae (D) of metasomal segments I–III terminus without sharp elongated spines; vesicular tabs variable, either well developed with hooked spine, or reduced and rounded …………………………………. 4 • One ventromedian (VM) carina present on metasomal segments I–IV; hemispermatophore lamina terminus pointed with hooked distal tip, inner base of lamina with small protuberance; leg ungues elongated and highly asymmetric; ventral aspect of leg tarsus clothed in an exaggerated cluster of elongated curved setae; dorsal carinae (D) of metasomal segments I–III terminus with exaggerated sharp elongated spines; vesicular tabs reduced and rounded, distal spine vestigial to obsolete in adults.……………………………….. genus Vejovoidus

4. Metasomal segment I usually as wide as long in male and wider than long in female, segment III never twice as long as wide, segment IV never three times longer than wide; setal pairs found on ventromedian (VM) carinae of segments I–IV, intercarinal area of VM carinae without setation; vesicular tabs well developed, equipped with conspicuous distal spine.……….… ……………………………………..genus Paruroctonus • Metasomal segments I–IV always longer than wide in both genders, segment III more than two times longer than wide, segment IV three times longer than wide; setal pairs lacking on ventromedian (VM) carinae of segments I–IV, instead are located between the VM; vesicular tabs reduced and rounded, distal spine vestigial to obsolete in adults …….…….….. genus Smeringurus

5. Genital operculum sclerites of female connected their entire length, operating as a single unit; hemispermatophore lamellar hook usually conspicuously bifurcated or with slight cleft is well developed with conspicuous basal constriction, and extends at least 30 % of the length of the lamella from dorsal trough; mating plug well developed and sclerotized, distal barb either smooth or toothed; chelal trichobothrium Dt positioned at or beyond palm midpoint; ib–it positioned adjacent to basal inner denticle (ID) to midfinger, never considerably proximal of basal ID; cheliceral ventral edge of movable finger without denticles or serrations; serrula medium to well developed, never vestigial……………. ……………….. (subfamily Syntropinae ) ….……….. 6 • Genital operculum sclerites of female separate on posterior one-fifth to two-fifths, operating as a single unit; hemispermatophore lamellar hook development is weak to medium with obsolete to minimal basal constriction, positioned basally to lamina midpoint; mating plug well developed either gelatinous or sclerotized, if sclerotized distal barb is smooth; chelal trichobothrium Dt positioned basally; ib–it positioned basal on finger, considerably proximal of basal inner denticle (ID); cheliceral ventral edge of movable finger variable, smooth, serrated, or with distinct denticles; serrula well developed.. (subfamily Vaejovinae ) …... 13

6. Basal pectinal teeth of female with sensorial areas; median (MD) and outer denticles (OD) of chelal fingers not serrate, MD + OD denticles density quotient medium, 51–74 (58); mating plug barb of hemispermatophore toothed; 2–4 ventral distal spinule pairs on leg tarsus; chelal trichobothrium Db located on or dorsal of digital (D1) carina; fixed finger trichobothria ib–it adjacent to basal inner denticle (ID); patellar trichobothrium v 3 positioned proximal to et 3; ventral edge of cheliceral movable finger with medium developed contiguous serrula (10–21 tines).. (tribe Syntropini ) ... 7 • Basal pectinal teeth (1 to as many as 4) of female lacking sensorial areas; median denticles (MD) of chelal fingers serrate; MD + OD denticle density quotient low, 30–42 (37); mating plug barb of hemispermatophore smooth; one ventral distal spinule pair on leg tarsus; chelal trichobothrium Db located on or ventral of digital (D1) carina; position of fixed finger trichobothria ib–it variable, from midfinger to slightly proximal of basal inner denticle (ID), based on species adult size; patellar trichobothrium v 3 positioned distal to et 3; ventral edge of cheliceral movable finger with well developed contiguous serrula (21–37 tines)…. (tribe Stahnkeini )….. 10

7. Chelae with obsolete to reduced carination; subdigital (D2) carina vestigial, not in strong profile; D2 carina positioned much closer to D1 than D3; ventrolateral and ventromedian carinae of metasomal segments I–IV obsolete to smooth, sometimes with some carination, never fully crenulate or serrate …………………..…. …………….(subtribe Syntropina ) ………………..… 8 • Chelae heavily carinated; subdigital (D2) carina well developed and in strong profile, sometimes occurring one-third the palm’s length; D2 carina positioned roughly equidistant between D1 and D3; ventrolateral and ventromedian carinae of metasomal segments I–IV smooth to crenulate, sometimes serrate …….………. ………(subtribe Thorelliina , subtrib. nov.) ……….... 9

8. Metasomal segments I–IV with paired ventromedian carinae; chelal fingers variable in length, but never extremely elongated, basal OD denticles located basally or suprabasally on fingers; chelal trichobothria ib–it, db– dt and eb–et positioned evenly over the fixed finger, not on the distal half; metasomal segments medium to heavy, segments I–II usually as wide or wider than long, length-to-width ratio 0.67–1.08 (0.89) and 0.83–1.31 (1.05) in males, and 0.67–1.03 (0.81) and 0.77–1.29 (0.95) in females; dorsal and dorsolateral carinae of metasomal segments I–IV flared posteriorly, distal denticle noticeably larger than other denticles.…… ………………………….genus Hoffmannius , gen. nov. • Metasomal segments I–IV with single ventromedian carina; chelal fingers extremely elongated, basal OD denticles located at finger midpoint; chelal trichobothria ib–it, db–dt and eb–et positioned on distal half of fixed finger; metasomal segments thin, all longer than wide in both genders, dorsal and dorsolateral carinae of metasomal segments I–IV not overly flared posteriorly and terminal denticle only slightly larger than other denticles.…………………………………..……. genus Syntropis

9. Carapace anterior edge with conspicuous continuous emargination originating from the lateral eyes, with a small median indentation; metasomal segments IV–V length-to-width ratio 1.7–2.2 (1.91) and 2.4–3.3 (2.75) in males, and, 1.5–2.3 (1.83) and 2.3–3.5 (2.72) in females; metasomal segments I–III ventromedian (VM) carinae usually granular to crenulate; chelal carinae usually granular to crenulate …….…. genus Kochius , gen. nov. • Carapace anterior edge lacking conspicuous emargination, if present never extending to lateral eyes, median area either straight or with wide subtle indentation; metasomal segments IV–V length-to-width 1.4–1.7 (1.54) and 1.8–2.3 (2.12) in males, and, 1.3–1.6 (1.45) and 1.9–2.4 (2.10) in females; metasomal segments I–III ventromedian (VM) carinae usually smooth to granular; chelal carinae usually smooth to strongly marbled. ……………….…. genus Thorellius , gen. nov.

10. Modification to basal pectinal teeth of female significant, lacking sensorial area in 1–4 teeth, blunted and ovoid to swollen and elongated, with little or no distal angling; OD denticles serrated, indistinguishable after OD-3; distal denticle elongated and hook-like with “whitish patch” ……………………….…………….. 11 • Modification to basal pectinal teeth of female marginalized, lacking sensorial area only in 1–2 teeth, not particularly swollen or elongated and showing some distal angling, or ovoid; OD denticles not serrated, all observable the entire length of both chelal fingers; distal denticle not overly elongated or hook-like, “whitish patch” minimal or absent ……………………………. 12

Figures

Figure 205: General distribution of scorpion subfamily Vaejovinae in North America with the ranges of genera Franckeus and Vaejovis “nigrescens” group delineated.