Kochius colluvius Ayrey, Jones & Myers, 2019

Ayrey, Richard F., Jones, Lawrence L. C. & Myers, Brandon, 2019, A new species of Kochius from Avra Valley, southern Arizona (Scorpiones Vaejovidae), Euscorpius 292, pp. 1-13 : 3-10

Genus Kochius Soleglad & Fet, 2008 Kochius colluvius Ayrey, Jones & Myers , sp. n.

( Figures 1–2, 5–18; Tables 1–2) http: //zoobank. org/urn: lsid: zoobank. org: act: 7BD1525F-

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TYPE LOCALITY. The type specimens were found, using a blacklight at night in Avra Valley, near Tucson, Pima County, Arizona (32.23694°N, 111.17148°W) at an elevation of 818 m a. s. l. The vegetation type is Sonoran Desert Scrub ( Fig. 11). Hoffmanius spinigerus (Wood, 1863), Hoffmannius confusus (Stahnke, 1940) , Hadrurus arizonensis Ewing, 1928 , and Centruroides sculpturatus Ewing, 1928 were found syntopically with Kochius colluvius sp. n.

TYPE MATERIAL. Holotype: ♂, Avra Valley , Pima County, Arizona, USA, 8 August 2016, leg. L. Jones, specimen RA2443 ( USNM) . Paratypes: 1♂, same locality, 12 April 2017, leg. L. Jones, specimen RA2561 ( RFA) ; 1♂, same locality, 8 August 2016, leg. L. Jones, specimen RA2445 ( RFA) ; 1♀, same locality, 10 October 2016, leg. R . F. Ayrey , specimen RA2447 ( RFA) .

OTHER MATERIAL EXAMINED. 2 ♂ ( RA 2557 and RA 2444), 5 ♀ ( RA2446 , RA2558, RA2559, RA2560, RA2567), Avra Valley , Pima County, Arizona, USA, 12 April 2017, leg. L. Jones ( RFA) .

ETYMOLOGY. The species is named after the colluvial soil microhabitat where all of the type specimens were found.

DIAGNOSIS. Small (27.42 mm) scorpions. Color is brownish yellow, lighter on the legs with underlying mottling on the carapace and mesosoma, red on tips of chela fingers ( Figs. 1–2). Pedipalp fingers not scalloped. Carapace coarsely granular. Mesosoma coarsely granular. Pedipalp movable finger has 7 ID denticles and fiXed finger has 6. Carapace of male is shorter than the fifth metasomal segment. Pectinal tooth count for males 14.30 [n=10], females 13.42 [n=12]. No subaculear tubercle present. Ventral surface of tarsomere II with single median row of spinules terminating distally with multiple spinule pairs.

DESCRIPTION. Based on holotype male, unless otherwise noted.

Color. Color is brownish yellow, lighter on the legs with underlying mottling on the carapace and mesosoma, red on tips of chela fingers.

Carapace. Anterior margin of carapace slightly emarginated. Carapace coarsely granular. Three lateral eyes on each side. Median furrow moderate, traversing the entire length but becoming less obvious distally. Ratio of median eyes location from anterior edge/carapace length 0.39; carapace length/ width at median eyes 1.20. Carapace of male is shorter than metasomal segment V.

Mesosoma. Tergites densely granular. Tergites III–VI tricostate. Tergite VII with two pairs of granular lateral carinae and one pair of crenulate carinae. Sternites III–VI finely granular and without carinae. Sternite VII with raised, whitish boss, restricted to the posteromedial third, “shaped like a truncated triangle” (GonzÁlez-SantillÁn & Prendini, 2013). Sternite VII with granular ventral lateral carinae. Presternites finely granular. Spiracles ovoid with median side rotated 35 degrees from posterior sternite margin.

Sternum ( Figs. 2, 8). Sternum is type 2.

Genital operculum ( Figs. 2, 8). Sclerites separated on posterior edge.

Pectines. Pectinal tooth count 14/14 for holotype male and 14/13 for paratype female. All pectinal teeth have eXterodistal angling with large sensorial area. Middle lamellae 9/9. Fulcra are present. Each fulcrum with 1-2 central setae.

Metasoma. Carapace of male is shorter than the fifth metasomal segment. Ratio of segment I length/width 0.92; of segment II length/width 1.17; of segment III length/width 1.45; of segment IV length/width 1.60; of segment V length/ width 2.50. Segments I-IV: dorsolateral carinae moderate, granular. Lateral supramedian carinae I–IV moderate, granular. Lateral inframedian carinae moderately granular on posterior 4/5 of segment I, posterior 3/5 of II, 3/5 of III, and obsolete on 2/5 of IV. Ventrolateral carinae I–IV moderate, granular. Ventral submedian carinae I-IV moderate. Dorsal and lateral intercarinal spaces very finely granular. Segment V: Dorsolateral carinae moderate. Lateromedian carinae weak and granular on basal 3/5, obsolete on distal 2/5. Ventrolateral and ventromedian carinae moderate. Intercarinal spaces finely granular.

Telson. Smooth. No subaculear tubercle present. Lateral aculear serrations (LAS) present in all specimens studied; males have 6–7 LAS “teeth” (n=2).

Chelicerae. Dorsal edge of movable cheliceral finger with two subdistal (sd) denticles. Ventral edge is smooth, with well developed serrula on distal half.

Pedipalps. Trichobothrial pattern type C ( Vachon, 1974) ( Fig. 13). Pedipalp fingers not scalloped. Trichobothria ib and it at base of fiXed finger. Pedipalp ratios: chela length/ width 2.67; femur length/width 2.72; patella length/width 2.32; fiXed finger length/carapace length 0.67. Chela. Well developed, mostly granular carinae. FiXed finger Median (MD) denticles aligned and divided into 6 subrows by 5 outer (OD) denticles and 6 ID denticles. Movable finger with 6 subrows, 5 OD denticles and 7 ID denticles (Soleglad & Sissom, 2001). Femur. Carinae moderate. Patella . Carinae strong, internal surface with very large granules on the DPSc carina.

Legs. Tarsi are lacking setal combs ( Fig. 12, A–D). Ventral surface of leg tarsomeres I–IV with single median row of spinules terminating distally with multiple spinule pairs ( Fig. 12).

Hemispermatophore. The lamina has a rounded terminus and lacks a distal crest. Due to a significant basal constriction, the internal edge of the lamina base curves inwards at the lamellar hook terminus. The terminus of the lamellar hook is modestly bifurcated. The base of the lamellar hook originates from both the dorsal and ventral troughs. The mating plug’s barb is toothed on its dorsal edge. Ratios: Lamellar_hook_L / Lamina_L = 0.378 and Trough_Diff / Lamellar_hook_ L = 0.293. Mating plug barb toothed with 9 teeth visible ( Fig. 15, B).

VARIABILITY. Pectinal tooth count 14/14 [n=3], 15/14 [n=1] and 15/15 [n=1], with a mean of 14.30 [n=10], standard deviation 0.483 for males and 13/13 [n=2], 13/14 [n=2], 14/13 [n=1] and 14/14 [n=1] with a mean of 13.42 [n=12], standard deviation 0.515 for females.

REPRODUCTION. Two adult females were kept alive in captivity to observe reproductive behavior. They were collected on 24 October 2016 and were assumed to be gravid. On 09 September 2017, first instars were observed on the back of specimen RA2447 ( Fig. 11). The juvenile count was 19. The 1 st instar orientation on the mother’s back was random, a not often seen behavior in Vaejovidae ( Hjelle, 1974; Ayrey, 2013). Postpartum behavior is as described in Ayrey (2013). On 20 September 2017, all of the juveniles were found to have molted to second instar ( Figure 12). They left the mother’s back on 22 September 2017. First instars were observed on the back of the second specimen on 20 September 2017 and postpartum behavior was as described above. The juvenile count on the second female was 17. Mean number of first instars was 18 (n=2).

DISTRIBUTION. Known only from the Avra Valley, Pima County, Arizona, USA.

Species Comparison

Chihuahuanus russelli ( Williams, 1971) and C. crassimanus (Pocock, 1898) : differ from K. colluvius sp. n. by having “subtle but distinct proXimal scallop leaving small open space between fingers when chela closed” ( Williams, 1971). These species are also widely allopatric with K. colluvius sp. n.

Kochius hirsuticauda (Banks, 1910) : differs from K. colluvius sp. n. by having higher pectinal tooth counts and by having a large number of macrosetae on the telson, of the male, giving it the appearance of a comb ( Fig. 3). K. colluvius sp. n. is also widely allopatric with K. hirsuticauda (distance 340 miles).

Kochius magdalensis ( Williams, 1971) : differs from K. colluvius sp. n. by having “subtly scalloped pedipalp fingers in both seXes” ( Williams, 1971), higher pectinal tooth count and by 9 important morphometric ratios ( Table 2). K. colluvius is also widely allopatric with K. magdalensis , which is limited to Baja California Sur, MeXico.

Kochius sonorae ( Williams, 1971) : differs from K. colluvius sp. n. by 9 important morphometric ratios ( Table 2). K. colluvius sp. n. is also widely allopatric with K. sonorae (distance 475 miles).