Micropholcus maysaan Huber & Meng 2024, sp. nov.
Creators: name: Huber, Bernhard A.
name: Meng, Guanliang
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Micropholcus
Micropholcus maysaan

description: Micropholcus maysaan Huber sp. nov.
Figs 3 H, 47, 48, 49, 50, 51
Type material.
Holotype. Saudi Arabia – Mecca • ♂; NW of Maysaan; 20.7717 ° N, 40.7985 ° E; 2560 m a. s. l.; 29 Mar. 2024; B. A. Huber leg.; KSMA. Paratypes. Saudi Arabia – Mecca • 4 ♂♂, 5 ♀♀; same collection data as for holotype; ZFMK Ar 24667 to 24668.
Other material.
Saudi Arabia – Mecca • 2 ♀♀, 4 juvs; in pure ethanol; same collection data as for holotype; ZFMK SA 140 – Al Bahah • 2 ♂♂, 6 ♀♀; NW of Al Bahah, ‘ site 2 ’; 20.2095 ° N, 41.3700 ° E; 2250 m a. s. l.; 16 Mar. 2024; B. A. Huber leg.; ZFMK Ar 24669 • 1 ♂, 4 ♀♀; in pure ethanol; same collection data as for preceding; ZFMK SA 88 • 1 ♂; S of Al Bahah, ‘ site 2 ’; 19.9896 ° N, 41.4373 ° E; 1250 m a. s. l.; 17 Mar. 2024; B. A. Huber leg.; ZFMK Ar 24670.
Diagnosis.
Distinguished from other species in northern Saudi Arabian group (M. bashayer sp. nov., M. tanomah sp. nov.) by strongly widened dorsal hinged process of procursus (Fig. 48 C), by pointed process originating from embolus directed towards bulbous part (arrowed in Fig. 48 E); from M. bashayer sp. nov. also by darkened anterior area of epigynal plate (Fig. 50 A; rather than central area, cf. Fig. 46 A); from M. tanomah sp. nov. also by wider main bulbal process (Fig. 48 D), and by epigynal ‘ knob’ in central rather than posterior position on epigynal plate (Figs 50 A, B, 51 A, B). From species of the southern Saudi Arabian group and M. jacominae by shorter male palpal trochanter apophysis (Fig. 47 C), internal female genitalia with membranous central element rather than distinct arc (Fig. 49 C), and without crescent-shaped structures.
Description.
Male (holotype). Measurements. Total body length 3.1, carapace width 1.1. Distance PME - PME 200 µm; diameter PME 90 µm; distance PME - ALE 30 µm; distance AME - AME 40 µm; diameter AME 50 µm. Leg 1: 26.3 (6.6 + 0.5 + 6.6 + 11.3 + 1.3), tibia 2: 4.2, tibia 3: 2.7, tibia 4: 3.7; tibia 1 L / d: 69; diameters of leg femora (at half length) 0.10–0.11; of leg tibiae 0.09–0.10.
Colour (in ethanol). Carapace pale ochre-yellow with distinct brown mark, 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 Fig. 3 H. Ocular area slightly raised. Carapace without thoracic groove. Clypeus unmodified. Sternum wider than long (0.72 / 0.58), unmodified. Abdomen oval, approximately twice as long as wide.
Chelicerae. As in Fig. 49 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. 47; 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. 48 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 distinctively widened dorsal hinged process. Genital bulb (Fig. 48 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 pointing towards globular part of bulb; 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 eight males (incl. holotype): 5.1–7.1 (mean 6.1). Males from NW of Maysaan and from NW of Al Bahah appear essentially identical. In the single male from S of Al Bahah, the shape of the dorsal hinged process of the procursus is slightly different: its widest point is at one third of its length rather than at half-length. Also, the retrolateral bulbal process in this specimen is (in prolateral view) less strongly protruding from behind the prolateral process.
Female. In general, very similar to male but anterior leg femora proximally not darkened. Tibia 1 in ten females: 4.6–5.5 (mean 4.9). Epigynum (Fig. 50 A, B) protruding, anterior plate oval, with prominent knob-shaped process medially; posterior epigynal plate very short and indistinct. Internal genitalia (Figs 49 C, 50 C, D, 51 C, D) with pair of oval pore plates in transversal position; with pair of lateral sclerites and complex system of membranous structures. Females from NW of Maysaan and from NW of Al Bahah appear essentially identical. No female is available from S of Al Bahah.
Etymology.
The species name is derived from the type locality; noun in apposition.
Distribution.
Known from three localities in Saudi Arabia, in Mecca and Al Bahah Provinces (Fig. 13 C).
Natural history.
At the type locality, the spiders were found in small caverns under large boulders on a hill (Fig. 14 D), where they were tightly pressed against the rock on the ceiling. Upon disturbance, they were very reluctant to move; only when the sparse sheet of silk covering the spider was removed, they started to run away over the rock. NW of Al Bahah most specimens were collected from a small hole under a flat rock; distances between specimens ranged from ~ 10–20 cm. One egg sac contained ~ 12 eggs, with an egg diameter of 0.62 mm.
description: Published as part of Huber, Bernhard A. & Meng, Guanliang, 2024, Old World Micropholcus spiders, with first records of acrocerid parasitoids in Pholcidae (Araneae), pp. 95-182 in ZooKeys 1213 on pages 95-182, DOI: 10.3897/zookeys.1213.133178