Micropholcus bashayer 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

Micropholcus bashayer Huber sp. nov.

Figs 3 G , 43 , 44 , 45 , 46

Type material.

Holotype. Saudi Arabia – ‘ Asir • ♂; NW of Al Bashayer ; 19.8194 ° N, 41.8824 ° E; 1850 m a. s. l.; 19 Mar. 2024; B. A. Huber leg.; KSMA . Paratypes. Saudi Arabia – ‘ Asir • 8 ♂♂, 10 ♀♀; same collection data as for holotype; ZFMK Ar 24665 to 24666 .

Other material.

Saudi Arabia – ‘ Asir • 2 ♂♂, 3 ♀♀; in pure ethanol; same collection data as for holotype; ZFMK SA 96 .

Diagnosis.

Distinguished from most similar known species ( M. maysaan sp. nov.) by less widened dorsal hinged process of procursus (Fig. 44 C ), by pointed projection of bulbal process (arrowed in Fig. 44 E ) not directed towards bulbous part, and by darkened central area of epigynal plate (Fig. 46 A ; rather than anterior part, cf. Fig. 50 A ). From third species in northern Saudi Arabian group ( M. tanomah sp. nov.) by wider main bulbal process (Fig. 44 D ), by epigynal ‘ knob’ in central rather than posterior position on epigynal plate (Fig. 46 A ). From species of the southern Saudi Arabian group and M. jacominae by shorter male palpal trochanter apophysis (Fig. 43 C ), internal female genitalia with membranous central element rather than distinct arc (Fig. 45 C ) and without crescent-shaped structures.

Description.

Male (holotype). Measurements. Total body length 3.0, carapace width 1.0. Distance PME - PME 195 µm; diameter PME 80 µm; distance PME - ALE 20 µm; distance AME - AME 20 µm; diameter AME 50 µm. Leg 1: 23.7 (6.0 + 0.5 + 5.9 + 10.1 + 1.2), tibia 2: 3.6, tibia 3: 2.3, tibia 4: 3.4; tibia 1 L / d: 66; diameters of leg femora (at half length) 0.10–0.11; of leg tibiae 0.09.

Colour (in ethanol). Carapace pale ochre-yellow with distinct brown mark, ocular area and clypeus also with 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, dorsally and laterally with whitish internal marks.

Body. Habitus as in M. maysaan sp. nov. (cf. Fig. 3 H ). Ocular area slightly raised. Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.68 / 0.48), unmodified. Abdomen oval, approximately twice as long as wide.

Chelicerae. As in Fig. 45 A, B ; with pair of distal apophyses near laminae, each with two cone-shaped hairs; with pair of distinct proximal frontal apophyses; without proximal lateral processes.

Palps. As in Fig. 43 ; coxa unmodified; trochanter with long ventral apophysis with distinct proximal retrolateral hump and modified hair on distal tip; femur distally widened, otherwise unmodified; femur-patella joints shifted toward prolateral side; tibia-tarsus joints shifted toward retrolateral side; tarsus with large tarsal organ. Procursus (Fig. 44 A – C ) 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, and distinctive dorsal hinged process. Genital bulb (Fig. 44 D, E ) with strong proximal sclerite; with two sclerotised processes of unclear homology: prolateral process large but simple, with small, pointed side branch; retrolateral process very simple, originating from basis of embolus and directed parallel to prolateral process; and mostly semi-transparent short embolus with membranous extension.

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 nine males (incl. holotype): 5.5–6.7 (mean 6.0).

Female. In general, very similar to male but anterior leg femora proximally not darkened. Tibia 1 in ten females: 4.4–5.4 (mean 4.9). Epigynum (Fig. 46 A, B ) protruding, anterior plate oval, with knob-shaped process medially; with large brown mark slightly divided medially, anteriorly light, posteriorly with small median dark line; posterior epigynal plate very short and indistinct. Internal genitalia (Figs 45 C , 46 C, D ) with pair of 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 ).

Natural history.

The spiders were found sitting on the undersides of large boulders, in small cave-like spaces between boulder and ground. One egg sac contained approximately 30 eggs, with an egg diameter of 0.60 mm. One female had an acrocerid larva in her book lung (Fig. 76 A – D ).

Figures

Figure 3. Micropholcus Deeleman-Reinhold & Prinsen; live specimens from Saudi Arabia A M. dhahran Huber, sp. nov., male from ‘ Asir, W of Dhahran Al Janub B M. harajah Huber, sp. nov., female with egg-sac from ‘ Asir, SE of Harajah C, D M. alfara Huber, sp. nov., male and female with egg-sac from ‘ Asir, S of Al Fara E M. abha Huber, sp. nov., male from ‘ Asir, N of Abha F M. tanomah Huber, sp. nov., male from ‘ Asir, NW of Tanomah G M. bashayer Huber, sp. nov., female with egg-sac from ‘ Asir, NW of Al Bashayer H M. maysaan Huber, sp. nov., male from Mecca, NW of Maysaan. Photographs BAH.

Figure 13. Known distribution of Micropholcus fauroti (Simon) (A) and of Old World Micropholcus in Mindanao (B), on the Arabian Peninsula (C) and in Morocco (D).

Figure 43. Micropholcus bashayer Huber, sp. nov.; male from Saudi Arabia, ‘ Asir, NW of Al Bashayer (ZFMK Ar 24665). Left palp in prolateral (A), dorsal (B), and retrolateral (C) views. Scale bar: 0.3 mm.

Figure 44. Micropholcus bashayer Huber, sp. nov.; male from Saudi Arabia, ‘ Asir, NW of Al Bashayer (ZFMK Ar 24665) A – C left procursus in prolateral, dorsal, and retrolateral views D, E left genital bulb in prolateral and retrolateral views; bold arrow in E points at retrolateral process originating from embolus. Abbreviation: e, embolus. Scale bars: 0.3 mm.

Figure 45. Micropholcus bashayer Huber, sp. nov.; from Saudi Arabia, ‘ Asir, NW of Al Bashayer A, B male chelicerae, frontal and lateral views (ZFMK Ar 24665) C cleared female genitalia, dorsal view (ZFMK Ar 24666). Scale bars: 0.3 mm.

Figure 46. Micropholcus bashayer Huber, sp. nov.; female from Saudi Arabia, ‘ Asir, NW of Al Bashayer (ZFMK Ar 24666) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Scale bars: 0.5 mm.

Figure 50. Micropholcus maysaan Huber, sp. nov.; female from Saudi Arabia, Mecca, NW of Maysaan (ZFMK Ar 24668) A, B abdomen, ventral and lateral views C, D cleared genitalia, ventral and dorsal views. Scale bars. 0.5 mm.

Figure 76. Acroceridae larvae in book lungs of Pholcidae; arrows point at larvae as seen in untreated abdomens A female abdomen of Micropholcus bashayer Huber, sp. nov., from Saudi Arabia, ‘ Asir, NW of Al Bashayer (ZFMK Ar 24666) B – D Acroceridae larva extracted from A E male abdomen of Micropholcus darbat Huber, sp. nov., from Oman, Dhofar, Wadi Darbat (ZFMK Ar 24672) F Acroceridae larva extracted from E G Mesabolivar eberhardi Huber, 2000, from Colombia, Magdalena, at Cascada Valencia (ZFMK Col 138) H Acroceridae larva extracted from G. Scale bars: 0.5 mm (A, E, G); 0.1 mm (B, F, H); 0.05 mm (C, D).