Micropholcus tanomah Huber, 2024

Huber, Bernhard A. & Meng, Guanliang, 2024, Old World Micropholcus spiders, with first records of acrocerid parasitoids in Pholcidae (Araneae), ZooKeys 1213, pp. 95-182 : 95-182

publication ID	https://doi.org/ 10.3897/zookeys.1213.133178
publication LSID	lsid:zoobank.org:pub:B8E6EE1A-023D-4B64-8D3A-C1843F0D8376
DOI	https://doi.org/10.5281/zenodo.13841462
persistent identifier	https://treatment.plazi.org/id/6D679588-8300-427F-89A7-6CA93102C27C
taxon LSID	lsid:zoobank.org:act:6D679588-8300-427F-89A7-6CA93102C27C
treatment provided by	ZooKeys by Pensoft
scientific name	Micropholcus tanomah Huber
status	sp. nov.

Treatment

Micropholcus tanomah Huber sp. nov.

Figs 3 F View Figure 3 , 5 A, G View Figure 5 , 6 C View Figure 6 , 7 C – G View Figure 7 , 9 B, F, G View Figure 9 , 10 A, B View Figure 10 , 11 A, F View Figure 11 , 12 A – D View Figure 12 , 39 View Figure 39 , 40 View Figure 40 , 41 View Figure 41 , 42 View Figure 42

Type material.

Holotype. Saudi Arabia – ‘ Asir • ♂; NW of Tanomah ; 19.0220 ° N, 42.1247 ° E; 2250 m a. s. l.; 19 Mar. 2024; B. A. Huber leg.; KSMA GoogleMaps . Paratypes. Saudi Arabia – ‘ Asir • 21 ♂♂, 24 ♀♀, 1 juv. (1 ♂, 1 ♀ used for SEM); same collection data as for holotype; ZFMK Ar 24663 to 24664 GoogleMaps .

Other material.

Saudi Arabia – ‘ Asir • 3 ♀♀, 4 juvs; in pure ethanol; same collection data as for holotype; ZFMK SA 100 GoogleMaps .

Diagnosis.

Distinguished from similar species in the northern Saudi Arabian group ( M. bashayer sp. nov., M. maysaan sp. nov.) by very slender main bulbal process (Fig. 40 D View Figure 40 ; wider in other species), and by epigynal ‘ knob’ in posterior rather than central position on epigynal plate (Fig. 42 A, B View Figure 42 ); from M. maysaan sp. nov. also by less widened hinged process of procursus (Fig. 40 C View Figure 40 ); from species of the southern Saudi Arabian group and M. jacominae by shorter male palpal trochanter apophysis (Fig. 39 C View Figure 39 ), internal female genitalia with membranous central element rather than distinct arc (Fig. 41 C View Figure 41 ), and without crescent-shaped structures.

Description.

Male (holotype). Measurements. Total body length 3.4, carapace width 1.2. Distance PME - PME 210 µm; diameter PME 80 µm; distance PME - ALE 20 µm; distance AME - AME 20 µm; diameter AME 45 µm. Leg 1: 28.7 (7.0 + 0.5 + 7.1 + 12.7 + 1.4), tibia 2: 4.5, tibia 3: 2.9, tibia 4: 4.0; tibia 1 L / d: 71; diameters of leg femora (at half length) 0.11–0.12; of leg tibiae 0.10.

Colour (in ethanol). Carapace pale ochre-yellow with distinct brown mark, ocular area not darkened, clypeus with very indistinct darker pattern; sternum monochromous whitish; legs ochre-yellow to light brown, patella dark brown, tibia-metatarsus joints with small brown ring, femur 1 ventrally proximally brown (less distinct also femur 2); abdomen pale ochre-grey, with indistinct darker internal marks.

Body. Habitus as in Fig. 3 F View Figure 3 . Ocular area slightly raised (distinct in frontal view). Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.74 / 0.58), unmodified. Abdomen oval, approximately twice as long as wide. Gonopore with four epiandrous spigots (Fig. 10 A View Figure 10 ). Spinnerets as in Fig. 9 F, G View Figure 9 .

Chelicerae. As in Fig. 41 A, B View Figure 41 ; with pair of distal apophyses near laminae, each with two cone-shaped hairs (Fig. 6 C View Figure 6 ); with pair of distinct proximal frontal apophyses; with pair of very low and indistinct lateral humps.

Palps. As in Fig. 39 View Figure 39 ; coxa unmodified; trochanter with long ventral apophysis with distinct proximal retrolateral hump and modified hair on distal tip (Fig. 9 B View Figure 9 ); femur distally widened, with subdistal ventral hump; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 40 A – C View Figure 40 ) proximally with sclerotised prolateral hump; at half length with prolateral sclerotised ridge transforming distally into transparent membrane, and brush of dorsal hairs; distally with small retrolateral ridge, large bifid membranous ventral-prolateral flap (Fig. 7 C, D View Figure 7 ), and dorsal hinged process. Genital bulb (Fig 7 F, G, 40 D, E) with strong proximal sclerite; with two sclerotised processes of unclear homology: prolateral process long and slender, with small, pointed branch on retrolateral side; retrolateral process simple, originating from basis of embolus and directed parallel to prolateral process; and mostly semi-transparent short embolus with membranous extensions.

Legs. Without spines, without curved hairs, without sexually dimorphic short vertical hairs; retrolateral trichobothrium of tibia 1 at 6 %; prolateral trichobothrium absent on tibia 1; tarsus 1 with> 20 pseudosegments, distally distinct.

Variation (male). Tibia 1 in 21 other males: 5.1–7.3 (mean 6.5). Carapace pattern very consistent. Abdomen usually with large white marks dorsally and laterally.

Female. In general very similar to male but anterior leg femora proximally not darkened; ocular area with large median and small lateral brown marks. Tibia 1 in 24 females: 4.4–5.9 (mean 5.2). Epigynum (Figs 10 B View Figure 10 , 42 A, B View Figure 42 ) protruding, anterior plate oval, mostly dark brown except medially posteriorly, with small knob-shaped process (Fig. 11 A View Figure 11 ) near posterior margin; posterior epigynal plate very short and indistinct, light brown. Internal genitalia (Figs 41 C View Figure 41 , 42 C, D View Figure 42 ) with pair of elongated pore plates in transversal position; with pair of lateral sclerites and complex system of membranous structures.

Etymology.

The species name is derived from the type locality; noun in apposition.

Distribution.

Known from type locality only, in Saudi Arabia, ‘ Asir Province (Fig. 13 C View Figure 13 ).

Natural history.

The spiders were found in caverns among and under boulders, often together with a representative of Smeringopus Simon, 1890 ( Araneae : Pholcidae ). Both species sometimes occurred in very high densities. In one case, a ceiling of a cave was estimated to measure ~ 3 m 2 and to contain ~ 250 large (adult and penultimate instar) specimens (i. e., with average distances between specimens of ~ 10 cm) (Fig. 15 View Figure 15 ). One egg sac had a diameter of 2.5 mm, and contained ~ 35 eggs. Egg diameters ranged from 0.69 to 0.71 mm.