The spider Micrathena shealsi Chickering, 1960 (Araneae, Araneidae): description of the male, with new data on its geographic distribution Author Argañaraz, Carina I. Author Rubio, Gonzalo D. text Zootaxa 2011 3104 52 58 journal article 45954 10.5281/zenodo.207326 a3151bb7-5427-4cb7-9a2f-868e0dc04d53 1175-5326 207326 Micrathena shealsi Chickering, 1960 ( Figs. 1–18 ; Map 19) Micrathena shealsi Chickering, 1960a : 8 , figs. 13–17 ( Holotype female from Sunchal, Argentina , deposited in Invertebrate Zoology Collection of Museum Comparative Zoology—MCZ 23053, not examined). Micrathena shealsi : Levi, 1985 : 458 , figs. 74–78; Platnick, 2011 . New records. ARGENTINA : Jujuy : Yala ( 24º07'13''S , 65º27'24''W , 1888m .a.s.l.), 20 May 1983 (P. Goloboff), 1 female (MACN-Ar 25178); Calilegua, Parque Nacional Calilegua, Seccional Aguas Negras ( 23º45'43.3''S , 64º51'04.7''W , 605m . a.s.l.), 27–31 January 2009 (M. Izquierdo, L. Zapata & M. Akmentis), 1 male (MACN-Ar 27850); same loc., near Monolito ( 23º40'27''S , 64º54'01''W , 1714m .a.s.l.), 19 October 2009 (G. Rubio & M. Pocco), 1 female (MACN-Ar 27851). Salta : Quebrada de San Lorenzo, site 1 ( 24°42'51.84"S , 65°31'6.96"W , 1833m .a.s.l.), 26–28 April 2006 (G. Rubio, J. Corronca, B. Cava, V. Olivo & A. González-Reyes), 2 females (MACN-Ar 27852); same loc., site 2 ( 24°43'9.60"S , 65°30'56.40"W , 1691m .a.s.l.), same date (same leg.), 6 specimens (IEBI); same loc., site 3 ( 24°43'16.80"S , 65°30'39.00"W , 1587m .a.s.l.), same date (same leg.), 1 specimen (IEBI); same loc., site 4 ( 24°43'17.04"S , 65°30'25.80"W , 1575m .a.s.l.), same date (same leg.), 2 specimens (IEBI); same loc., site 5 ( 24°43'16.32"S , 65°30'7.92"W , 1560m .a.s.l.), same date (same leg.), 7 specimens (IEBI); road to El Carmen, site 1 ( 24°31'13.36"S , 65°21'4.02"W , 1547m .a.s.l.), same date (same leg.), 2 specimens (IEBI); same loc., site 2 ( 24°30'33.30"S , 65°20'27.13"W , 1587m .a.s.l.), same date (same leg.), 1 specimen (IEBI); same loc., site 3 ( 24°30'15.84"S , 65°20'11.40"W , 1516m .a.s.l.), same date (same leg.), 2 specimens (IEBI). Tucumán : Cochuna ( 27°19'19.97"S , 65°55'38.01"W , 1162m .a.s.l.), 25 March 2011 (C. Argañaraz), 1 male (MACN-Ar 27853); same loc., 0 9 April 2011 (C. Argañaraz & G. Rubio), 4 males , 6 females (MACN-Ar 27854), and 1 male (MACN-Ar 27856); monument to El Indio ( 27° 2'54.24"S , 65°40'8.76"W , 1065m .a.s.l.), 21 February 2011 (G. Rubio & L. Acosta), 1 sub-adult male (MACN-Ar 27855). Diagnosis. Males of M. shealsi ( Figs. 1–7 , 9–15 ) resembles M. bifida (Taczanowski) from Peru by general habitus, and by the palp bearing a tegulum lobe in ectal view ( Levi 1985: figs. 45, 47 ) but it can be distinguished from it by the palpal morphology ( Figs. 5–7 , 9–13 ) ( M. shealsi has a distinctive shape of the median and terminal apophyses, Fig. 6 , 10 ). Females of M. shealsi differ from congeners by the absence of a scape on the epigynum ( Fig. 16 ) and by the ventral coloration (light sternum, and depigmented median area of the abdomen venter: Levi 1985 ). Micrathena shealsi was erroneously taken as “ M. nigrichelis with scape of epigynum torn off” ( Levi 1985 ). However, these species can be easily separated by the above-mentioned chromatic pattern ( Levi 1985 ), and by the dimensions of the cephalic region (smaller in M. shealsi ); the latter feature is also present in males. Description. Male from Cochuna, Tucumán (MACN-Ar 27856): Carapace orange (in nature—Fig. 18) or yellowish (in alcohol), black on sides and with a blackish longitudinal strip starting near the posterior eyes towards thoracic groove ( Figs. 1 , 18 ). Very shallow dimples on each side of thoracic groove. Chelicerae pale yellow. Sternum and coxae light yellow, with dark pigment near the articulation. Legs orange-brown, first pair darker. Coxa I with hook, femur II with groove ( Figs. 14–15 ). Tibia I-II with macrosetae; ventral side of femur II with row of 8–9 spines. Abdomen longer than wide, rectangle-shaped, without humps; yellowish-white dorsally (slightly orange in nature) with three black marks on each side, one dark median longitudinal strip on posterior two thirds; end of abdomen black; venter between epigastric furrow and spinnerets pale yellow, spinnerets and the rest of venter black-grayish ( Fig. 3 ). Palp with reddish-brown general color ( Figs. 17–18 ). Body total length from AME to tip of abdomen 5.51; carapace length 2.10, width 1.47; sternum length 0.91, width 0.52; abdomen length 3.57, width 0.98. Leg formula I/IV/II/III. Leg lengths (I/II/III/IV): femur 2.03/1.78/1.12/2.17; patella 0.64/0.58/0.38/0.49; tibia 1.54/1.22/0.63/1.20; metatarsus 1.15/1.12/0.56/1.33; tarsus 0.63/0.63/0.35/0.66; total leg 5.99/5.33/3.04/5.85. Female ( Holotype , MCZ 23053): See Chickering (1960a: 8, figs. 13–17) . Internal genitalia as in figure 8. Variation. Males (n=6): Body total length 4.83–5.51; carapace length 2.03–2.17, width 1.4–1.5; sternum width 0.50–0.56; abdomen length 3.01–3.57, width 0.87–1.05. Total leg (I/II/III/IV) 5.98–6.12/5.28–5.37/3.01–3.11/ 5.85–6.04. Natural history ( Figs. 17–18 ). Males of M. shealsi were found in most cases on the upper periphery of the female webs, hanging from a silk line. In only one case, a male was found in a small orb-web located under the female site. Females of M. shealsi sometimes build their web near other female webs, forming groups (of 2 to 5 individuals) in the lower stratum of vegetation, no higher than 60 cm . In such cases males were not observed. Ongoing ecological research (G. D. Rubio, unpublished) suggests that this species is strongly associated with the Yungas rainforest habitat. Geographic distribution ( Fig. 19 ). Micrathena shealsi was only known from the type locality “Sunchal, Argentina ” ( Chickering 1960a ). Although Levi (1985) assigned this locality to Salta Province, “Sunchal” in the latter does not fall within the rainforests region ( Fig. 19 ); in contrast, “Sunchal” or “El Sunchal” in Tucumán Province, seems more likely for a rainforest-dwelling spider. New records here provided reveal that M. shealsi has an extensive distribution in the Yungas, corresponding to the higher altitudinal belt (~ 1700 m .) of the mountain forests and rainforests from Tucumán, Salta and Jujuy Provinces ( Fig. 19 ).