Allagelena monticola, Chami-Kranon, Thanaphum, Likhitrakarn, Natdanai & Dankittipakul, Pakawin, 2007

Chami-Kranon, Thanaphum, Likhitrakarn, Natdanai & Dankittipakul, Pakawin, 2007, Allagelena monticola sp. n. (Araneae: Agelenidae), a new species of funnel­web spiders from northern Thailand, Zootaxa 1397, pp. 47-53 : 48-52

Allagelena monticola sp. n.

Figures 1–8

Material examined. Holotype: %, northern Thailand, Chiang Mai Province, Chomthong District, Doi Inthanon National Park, Doi Inthanon, evergreen hill forest along a road turning off from the summit road to Mae Chaem, ca. 500 m from checkpoint, 1650 m [18 31’ N, 98 29’ E], 19.viii.2005, sweeping lower vegetation, P. Dankittipakul leg. [ MHNG, TH AG­ 001].

Paratypes: 1%, 3Ψ, data as for the holotype [ MHNG, TH AG­ 002­005]; 1%, from the type locality, sweeping vegetation near dry swamp, 16.viii.2003, leg. S. Sonthichai [ TNHM, TH AG­ 006]; 3Ψ, sweeping lower and ground vegetation, 24.viii.2002, P. Dankittipakul & T. Chami­Kranon leg. [ TNHM, TH AG­ 007–009].

Diagnosis. Allagelena monticola sp. n. is similar to A. opulenta (L. Koch, 1878) . Males of the new species can be distinguished by: 1) the broad, sickle­shaped and dorsally curved retrolateral apophysis of the palpal tibia; 2) the tegulum of the bulb is provided with a triangular prolateral extension; 3) the partly sclerotized median apophysis is situated medially; the conductor is strongly sclerotized and provided with an apophysis. Females of the new species can be distinguished from those of A. opulenta by: 1) lateral lobes of epigyne pronounced; 2) epigynal atrium small, poorly delimited on the posterior margin; 3) copulatory ducts lightly sclerotized; 4) spermathecal heads originating laterally.

Etymology. Monticola , a compound Latin noun, derived from mons (pl. montes) meaning mountain, ending in – cola (= mountain dweller; highlander). The specific epithet refers to the habitats where this new species was collected.

Description. % (holotype): Medium­sized spider. Prosoma ( Fig. 1 ) longer than wide, widest between coxae III and IV, narrower in front; pars cephalica slightly elevated ( Figs 1–2 ). Carapace yellow, clothed with black short hairs, submarginal bands without pubescence ( Fig. 1 ); a row of long bristles running between ocular area and longitudinal fovea ( Figs 1–2 ). Eight eyes arranged in two strongly procurved rows ( Fig. 2 ); all eyes more or less subequal; PME slightly larger than AME; MOQ longer than wide, posterior width of MOQ slightly wider. Chilum divided. Chelicerae with distinct lateral condyle, cheliceral groove with three promarginal and four retromaginal teeth. Legs yellow; long and slender, with elongate hairs on dorsal side of coxae and trochanters; dark, feathery hairs presented on femora and tibiae; spines on dorsal tibiae, metatarsi and tarsi. Leg formula (from longest to shortest): 4­1­2­3.

Opisthosoma ( Fig. 1 ) elongate oval, widest behind mid length; dorsum dark reddish brown, with two pale longitudinal bands occupying anterior half of the opisthosoma, followed by four chevrons and then a series of transverse lines; venter pale, with two broad, irregularly shaped, longitudinal bands of dark purple, running between epigastric furrow and tracheal stigma in front of spinnerets. Apical article of posterior spinnerets slightly longer than basal article ( Figs 1, 3 ).

Male palp ( Figs 4–6 ): Patella ( Fig. 6 ) without apophysis and protuberance. Tibia strongly convex dorsally ( Fig. 5 ); retrolateral tibial apophysis (RTA) sickle­shaped, broad at base, gradually narrowing towards its dorsally curved tip ( Fig. 5 ). Tegulum (T) provided with triangular extension (TT), originating prolaterally, with round tip ( Fig. 5 ). Median apophysis (MA) more or less triangular, partly sclerotized, with a membranous base ( Figs 4–5 ). Conductor (C) strongly sclerotized and modified: Dorsally emarginated, prolaterally and retrolaterally with extensions ( Fig. 5 , peC; Fig. 4 , reC). Embolus (E) lightly sclerotized and weakly pigmented in its central portion, strongly curved, narrowing towards the tip, accommodated by the conductor; lateral margins distinctly darker than the central portion.

Total length 7.42. Dorsal shield of prosoma 3.41 long, 2.75 wide. Opisthosoma 4.03 long, 2.26 wide. Eye sizes and interdistances: AME 0.18, ALE 0.18, PME 0.15, PLE 0.16; AME–AME 0.10, AME–ALE 0.18, PME–PME 0.18, PME–PLE 0.18, ALE–PLE 0.10; MOQ 0.58 long, front width 0.44, back width 0.46. Clypeus 0.41 high.

Leg measurements:

I II III IV Femur 4.15 3.95 3.40 4.48 Patella 0.83 0.81 0.82 0.85 Tibia 5.17 4.72 3.81 4.74 Metatarsus 4.63 4.05 3.75 5.46 Tarsus 1.89 1.80 1.69 1.98 Total 16.67 15.33 13.47 17.51

Ψ (one of the paratypes): As the male but smaller in size, posterior part of prosoma round and clearly broader, ocular region distinctly narrower. Dorsal shield of prosoma clothed with reddish brown hairs forming two broad longitudinal bands running over its entire length, bands interspersed by a pale, hairless median longitudinal line. Fine elongate hairs presented along the lateral margins of the dorsal shield of prosoma. Legs with distinct dark greenish­brown annulations, particularly on femora and tibiae. Leg formula (from longest to shortest): 4­1­2­3.

Opisthosoma ovate, the posterior end pointed. Dorsum of opisthosoma dark reddish brown, provided with relatively short pale longitudinal bands occupying less than half of opisthosomal length, followed by five chevrons and a series of transverse lines. Apical article of the posterior spinnerets slightly longer than the basal one.

Epigyne and its internal structures ( Figs. 7–8 ). Epiynal atrium (A) shallow, roughly trapezium­shaped, the posterior margin indistinctly delimited. Copulatory orifices (CO) located close to the middle of the atrium. Copulatory ducts (CD) broad, lightly sclerotized, gradually narrowing towards the orifice. Spherical spermathecae (S) situated posteriorly, close to the epigastric furrow; spermathecal heads (SH) lightly sclerotized, originating laterally. Fertilization ducts (FD) thin, membranous, with compressed lumen.

Total length 6.96. Dorsal shield of prosoma 3.15 long, 2.53 wide. Opisthosoma 3.81 long, 2.19 wide. Eye sizes and interdistances: AME 0.16, ALE 0.16, PME 0.15, PLE 0.15; AME–AME 0.09, AME–ALE 0.16, PME–PME 0.16, PME–PLE 0.18, ALE–PLE 0.10; MOQ 0.54 long, front width 0.40, back width 0.42. Clypeus 0.38 high.

Natural history. Specimens of Allagelena monticola sp. n. were collected by sweeping lower vegetation, suggesting that its web is built in grass or shrubs. Males and females matured late in the rainy season (September).

Distribution. Known only from the type locality, a remnant patch of evergreen hill forest at 1650 m alt. surrounded by degraded forests interspersed with pine trees. The forest of this altitudinal zone (1600–1800 m asl) is an ecotone of great ecological importance, situated between the constantly moist lower montane forest that occupies altitudes from 1800 to 2500 m and the mixed dipterocarp forest from 900 to 1300 m.

Figures

FIGURES 1 – 3. Allagelena monticola sp. n., male holotype. (1). Habitus, dorsal view. (2). Anterior part of dorsal shield of prosoma showing eye arrangement, dorsal view. (3). Posterior part of opisthosoma showing spinnerets, ventral view. Scale bars = 1.0 mm.

FIGURES 4 – 8. Allagelena monticola sp. n., male holotype (4 – 6) and female paratype (7 – 8). (4). Male palp, ventral view. (5). Ditto, prolateral view. (6). Ditto, retrolateral view. (7). Epigyne, ventral view. (8). Vulva, dorsal view. Scale bars = 0.5 mm (4 – 6) and 0.25 mm (7 – 8). Abbreviation: A, Epigynal atrium; C, Conductor; CD, Copulatory duct; CO, Copulatory orifice; E, Embolus; FD, Fertilization duct; MA, Median apophysis; peC, Prolateral extension of conductor; reC, Retrolateral extension of conductor; RTA, Retrolateral tibial apophysis; S, Spermatheca; SH, Spermathecal head, T, Tegulum; TT, Tegular tubercle.