Vaejovis stetsoni Ayrey et Myers, 2019

Ayrey, Richard F. & Myers, Brandon, 2019, A new “ vorhiesi ” group species of Vaejovis from the Galiuro Mountains, southern Arizona (Scorpiones: Vaejovidae), Euscorpius 284, pp. 1-14 : 4-13

Vaejovis stetsoni Ayrey et Myers , sp. n.

( Figs. 1–17; Tables 1 –2) http: //zoobank. org/urn: lsid: zoobank. org: act: ADB75D58-

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TYPE MATERIAL. Holotype female, Galiuro Mountains , Graham County, Arizona, USA, 32.46248°N, 110.29403°W, 10 August 2015 (E. R. Stetson), specimen #RA2077 ( USNM) . Paratype females, Galiuro Mountains , Graham County, Arizona, USA, 10August 2015 (E. R. Stetson), specimen #RA2075 & RA2085, ( RFA) . Paratype female, Galiuro Mountains , Graham County, Arizona, USA, 12 May 2013 ( R. F. Ayrey), specimen #RA835, ( RFA) . Paratype male, Galiuro Mountains , Graham County, Arizona, USA, 10 August 2015 (E. R. Stetson), specimen #RA2081 ( USNM) .

DISTRIBUTION. Known only from the type locality, Galiuro Mountains , Graham County, Arizona, USA .

ETYMOLOGY. This species is named in honor of Eric Stetson who collected most of the type specimens.

DIAGNOSIS. Small (18.35 mm) scorpions. Color is dark brown, lighter on the legs, with underlying mottling on carapace and mesosoma. (see Figure 1). Pedipalp movable finger with 6 ID denticles and fixed finger with 5. Carapace of female is longer than the fifth metasomal segment. Pectinal tooth count for females 11.25 [n=12], males 13.20 [n=10]. Large, well developed subaculear tubercle.

Description. Based on holotype female, unless otherwise noted, see Figure 4 for dorsal and ventral views.

Color. Color is dark brown, lighter on the legs, telson reddish. Faint underlying mottling on carapace, mesosoma, metasoma, telson, pedipalps and legs.

Carapace. Anterior margin of carapace moderately emarginated, posterior margin slightly emarginated. Carapace finely granular. Three lateral eyes on each side. Median furrow moderate and traverses entire length of carapace. Ratio of median eyes location from anterior edge/carapace length 0.35; carapace length/width at median eyes 1.06. Anterior edge to median eyes 0.93. Six macrosetae are situated on anterior edge of carapace. Carapace of female is longer than metasomal segment V.

Mesosoma. Tergites moderately granular on posterior half of Tergites I-VI. Tergite VII with strong crenulated dorsal lateral and lateral supramedian carinae. Sternites III-VI smooth. Sternite VII with weakly granular ventral lateral carinae on posterior half. Presternites smooth.

Spiracles ovoid with median side rotated 35° from posterior sternite margin. Sternites with variable number of microsetae. Sternum ( Figs. 2, 8). Sternum is Type 2.

Genital Operculum ( Figs. 2, 8). Sclerites separated on posterior one-fifth.

Pectines. Pectinal tooth counts 11/11 [n=3], 11/12 [n=1] and 12/11[n=2], with a mean of 11.25 [n=12], standard deviation 0.4522 for females and 13/13 [4] and 14-14 [1] with a mean of 13.2 [n=10], standard deviation 0.4216 for males. All pectinal teeth have exterodistal angling with large sensorial area. Middle lamellae 7/7. Fulcra are present. Each fulcra with 1-3 central setae.

Metasoma. Carapace of female is longer than the fifth metasomal segment. Ratio of segment I length/width 0.74; of segment II length/width 0.87; of segment III length/width 0.97; of segment IV length/width 1.41; of segment V length/ width 2.07. Segments I-IV: dorsolateral carinae strong and granular with distal denticle of I-IV enlarged and spinoid. Lateral supramedian carinae I-IV strong and granular with enlarged spinoid distal denticle. Lateral inframedian carinae moderately granular on posterior 3/5 of segment I, moderately granular on posterior 1/2 of segments II-III, weakly granular on posterior 2/5 of segment IV. Ventrolateral carinae weakly granular on posterior 3/5 of segment I, weakly granular on posterior 1/5 of segment II, moderately granular on posterior 4/5 of segment III, strongly granular on segment IV. Ventral submedian carinae weakly granular on segment I-II, moderately granular on segment III-IV. Dorsal and lateral intercarinal spaces very finely granular. Segment I-IV ventral submedian setae 3/3. Segment V: Dorsolateral carinae strong, distally crenulate, basally granular. Lateromedian carinae weak and granular on basal 3/5, obsolete on distal 2/5. Ventrolateral and ventromedian carinae strong. Intercarinal spaces finely granular. Segment V ventrolateral setae 4/4.

Telson. Smooth with 4 pairs of large setae on the ventral surface, 3 large setae along both lateral edges of the vesicle and numerous smaller setae. Large, prominent subaculear tubercle present (see illustration above). Lateral aculear serrations (LAS) are present. Female teeth number 3-4 (n=3), male paratype with 6 teeth.

Chelicerae. Dorsal edge of movable cheliceral finger with two subdistal (sd) denticles. Ventral edge is smooth, with well developed serrula on distal half. Fixed cheliceral finger with four denticles: basal, median, subdistal and distal. Basal and median denticles forked. Typical for genus.

Pedipalps. Trichobothrial pattern type C ( Vachon, 1974) (see Fig. 6). Trichobothria ib and it at the base of fixed finger. Pedipalp ratios: chela length/width 4.02; femur length/width 3.02; patella length/width 2.73; fixed finger length/carapace length 0.61. Chela. Carinae moderate. Fixed finger median (MD) denticles aligned and divided into 6 subrows by 5 outer (OD) denticles and 5 inner (ID) denticles. Movable finger with 6 subrows, 5 OD denticles and 6 ID denticles (Soleglad & Sissom, 2001). Femur. Carinae moderate. Patella . Carinae strong, internal surface with very large granules on the DPSc carina.

Legs. Ventral surface of tarsomere II with single median row of spinules terminating distally with one spinule pair.

Hemispermatophore. All descriptions based on left hemispermatophore. Wide hemispermatophore trunk. Lamellar hook sclerotized, strongly bifurcated at distal tip, and relatively short with a ratio of its length to the lamina length of 0.28. Trough difference also provides an indication of relative shortness of lamellar hook when comparing the two with a ratio 0.67. Modest distal crest is present on the inner distal aspect of the lamella, which is also visible from the ventral surface.

Measurements (mm) are as follows: trough difference, 0.33; lamellar hook length, 0.49; lamina length, 1.74; trunk width, 0.53; lamina width, 0.39; ratio of lamellar hook length to lamina length, 0.28; ratio of trunk difference to lamellar hook length, 0.67.

Variability. Pectinal tooth count 11/11 [n=3], 11/12 [n=1] and 12/11[n=2], with a mean of 11.25 [n=12], standard deviation 0.452267 for females and 13/13 [4] and 14-14 [1] with a mean of 13.2 [n=10], standard deviation 0.421637 for males. The size and shape of the pectines show sexual dimorphism in males and females. The pectinal teeth are longer and more numerous in males (see Figure 6). No variability of fixed finger ID denticle count was noted in Vaejovis stetsoni , while variability is seen in many other species in the “ vorhiesi ” group ( Ayrey, 2012; Ayrey, 2013b; Ayrey & Webber, 2013).

AFFINITIES. Map in Fig. 18 shows the type localities of the 20 currently described species of Vaejovis from Arizona, western New Mexico and Sonora, Mexico, as well as Vaejovis stetsoni sp. n.

Vaejovis jonesi , V. lapidicola , V. paysonensis , V. crumpi , V. bigelowi , V. trinityae , and V. grayae : all exhibit seven inner denticles (ID) on the chelal movable finger while V. stetsoni exhibits 6. All seven species are also widely allopatric with V. stetsoni .

Vaejovis tenuipalpus : has 6 ID denticles on both the fixed and movable fingers while V. stetsoni h as 5 ID d enticles o n the fixed finger. V. tenuipalpus is also widely al lopatric wi th V. stetsoni .

Of the 12 described species with 6 inner denticles (ID) on the chela movable finger, n ine species were f ound t o be widely allopatric with V. stetsoni . They are V. vorhiesi , V. feti , V. halli , V. bandido , V. grahami , V. troupi , V. islaserrano and V. patagonia ; see map in Fig. 13.

Morphometric comparisons were made to the four closest species, V. brysoni , V. cashi , V. deboerae , and V. electrum . Each of these species exhibited some morphometric ratios, which do not overlap with V. stetsoni sp. n. ( Vaejovis brysoni exhibits four such morphometric ratios; V. cashi , seven; V. deboerae , six; and V. electrum , four)

COMMENTS ON LOCALITY AND LIFE STRATEGY. The type specimens were found under rocks or using a blacklight at night in the Galiuro Mountains, Graham County, Arizona (32.46248°N 110.29403°W) at an elevation of 1337 m a. s. l. The vegetation type is mesic, mixed evergreen oak woodland, see Figures 13 and 14. Hoffmannius spinigerus, Centruroides sculpturatus, and Pseudouroctonus apacheanus were found syntopically with V. stetsoni during four field trips to the Galiuro Mountains. This species lives in oak leaf litter and under rocks that are embedded in the ground in oak leaf litter. Several adult females were kept alive to determine 1 st instar behavior. Of those, 5 gave birth with the average number of 1 st instars being 12.60 (5), standard deviation 2.70. The 1 st instar behavior was as previously described ( Hjelle, 1974; Ayrey, 2012; Ayrey, 2013; Ayrey & Soleglad, 2014).