Pholcus Walckenaer, 1805

Zhang, Feng & Zhu, Ming-Sheng, 2009, A review of the genus Pholcus (Araneae: Pholcidae) from China, Zootaxa 2037 (1), pp. 1-114 : 6-8

publication ID	https://doi.org/ 10.11646/zootaxa.2235.1.2
DOI	https://doi.org/10.5281/zenodo.5327586
persistent identifier	https://treatment.plazi.org/id/03D88781-FFC9-FF81-FF15-4938FD82FBC1
treatment provided by	Felipe
scientific name	Pholcus Walckenaer, 1805
status

Treatment

Pholcus Walckenaer, 1805 View in CoL View at ENA

Pholcus Walckenaer 1805: 80 View in CoL . Simon 1893: 470–471. Huber 2000: 77. Huber 2001: 108–111. Hu 2001: 81.

Type species: Aranea phalangioides Fuesslin, 1775 , by subsequent designation.

Diagnosis. The most useful characters in distinguishing Pholcus from other genera in the family Pholcidae are the male genital structures, especially three projections of the tarsus bulb, traditionally called the uncus, the appendix and the embolus. The uncus is usually large, rather flat, heavily sclerotized, and is provided with many teeth or scales. The appendix is smaller (even absent in some species), usually hook-shaped, also sclerotized, and is either a single rod or split into two or even three parts. The embolus lies between the uncus and appendix, is soft and transparent, and is thus easy to overlook ( Huber 2001). Other characters are the conservative male chelicerae (with various apophyses), the shape of the procursus (usually with ventral boss and complicated tip), and in the female, the knob-, necktie-, whip- or worm-shaped apophysis on the often roughly triangular, rectangular or oval epigynum.

Description (refers to Chinese species of Pholcus only). Medium to large-sized pholcids, the body frequently being 4 to 10 mm in length. They generally have flat, plate-shaped cephalothoraces ( Figs. 17C View FIGURE 17 and 30C View FIGURE 30 ), pale ochre with distinctive brown marks of three general patterns in China: the first pattern ( Figs. 15C View FIGURE 15 , 20C View FIGURE 20 , 23C View FIGURE 23 , 25C View FIGURE 25 , 32C View FIGURE 32 , 37C View FIGURE 37 , 41C View FIGURE 41 or 52C) we named ‘Peking-opera-mask’ type, most species belong to it; the second ( Figs. 3C View FIGURE 3 , 4A View FIGURE 4 , 14D View FIGURE 14 , 21D View FIGURE 21 , 26C View FIGURE 26 , 36C View FIGURE 36 or 46C) we named ‘butterfly’ type, some species belong to it; the third ( Figs. 28A View FIGURE 28 or 10D) we named ‘stripe’ type, only two species are in this group. Carapace with black median line but no thoracic furrow. Clypeus generally pale ochre, with or without marks, high and without sexual modifications. The eye region is light brown, more or less elevated ( Figs. 40A View FIGURE 40 and 43A View FIGURE 43 ); most species have eight eyes in three groups, two median AMEs as a group and others in two lateral triads; most lateral triads not on eye-stalks, sometimes male triads on short ( Figs. 27C View FIGURE 27 and 32C View FIGURE 32 ) or longer eye-stalks ( Figs. 39A–B View FIGURE 39 ). A few species have six eyes, such as P. elongatus redescribed below ( Fig. 10D View FIGURE 10 ). Chelicerae fused at base, with lamina opposing cheliceral fang. In females normal, male chelicerae are frequently equipped with two or three pairs of special apophyses, often species-specific in morphology: the first pair, dark distal apophyses with two small modified hairs on each ( Figs. 18D–E View FIGURE 18 , 57E–F View FIGURE 57 ), a second pair of light apophyses proximolaterally ( Figs. 23E View FIGURE 23 , 29E View FIGURE 29 and 32E View FIGURE 32 ), and finally, a pair of unsclerotized apophyses proximocentrally which may be very small ( Figs. 33E View FIGURE 33 and 35E View FIGURE 35 ), or even absent in some species ( Figs. 27D View FIGURE 27 and 29E View FIGURE 29 ). Sternum pale ochre, about as wide as or wider than long, with varying brown patterns, some species with three or four pairs of submarginal pale patches and central pale patch ( Figs. 45F View FIGURE 45 and 52F View FIGURE 52 ), some species have no markings ( Fig. 21F View FIGURE 21 ), some species with only median markings ( Figs. 17F View FIGURE 17 and 33F View FIGURE 33 ), others with irregular or regular spots ( Figs. 11F View FIGURE 11 , 24F View FIGURE 24 and 29F View FIGURE 29 ). Labium and endites generally light brown and unmodified.

Pedipalps are unmodified in females ( Fig. 38A View FIGURE 38 ), but conspicuously large and strong in males ( Figs. 29H–I View FIGURE 29 and 42H–I View FIGURE 42 ). Their complex morphology has been well documented by Uhl et al. (1995). The male palps are generally described as below. Coxa unmodified. Trochanter generally with a ventral apophysis which is long or short in different species ( Figs. 29H View FIGURE 29 and 27H View FIGURE 27 ); some species with a retrolateral apophysis provided distally with a strong modified hair ( Fig. 38D View FIGURE 38 ). Femur large, with a ventral bulge which corresponds to a depression on the procursus ( Figs. 16I View FIGURE 16 , 20I View FIGURE 20 and 26I View FIGURE 26 ), and sometimes with a dorsal projection retrolaterally ( Figs. 3G View FIGURE 3 , 26I View FIGURE 26 and 42I View FIGURE 42 ). Patella generally triangular in retrolateral view, and unmodified ( Figs. 17I View FIGURE 17 , 20I View FIGURE 20 and 24H View FIGURE 24 ). Tibia swollen, robust, spindle-shaped ( Figs. 3F View FIGURE 3 , 24H View FIGURE 24 and 32H View FIGURE 32 ), bears two trichobothria laterally and dorsally ( Figs. 35H View FIGURE 35 , 41H View FIGURE 41 and 47G View FIGURE 47 ); sometimes with an ear-shaped tubercle prolaterally ( Figs. 11H View FIGURE 11 , 35H View FIGURE 35 and 37H View FIGURE 37 ) or a triangular projection ventrally ( Figs. 15H View FIGURE 15 , 43I View FIGURE 43 and 46H View FIGURE 46 ). The tarsus consists of two parts: a proximal part carrying several bristles, a capsulate tarsal organ and the genital bulb ( Figs. 47F View FIGURE 47 , 59C View FIGURE 59 and 63I View FIGURE 63 ), and a distal part (also called the procursus), a massive organ with many heavily sclerotized structures. The tip of the procursus is very complex in structure and has important diagnostic characters. The bulb is a whitish globular part with three projections, which are traditionally called uncus, appendix and embolus ( Figs. 5I View FIGURE 5 , 52H View FIGURE 52 and 36H View FIGURE 36 ); the uncus is usually large, rather flat, heavily sclerotized, and is provided with many teeth or scales ( Figs. 7I View FIGURE 7 , 54F View FIGURE 54 and 56H View FIGURE 56 ); the appendix is smaller (even absent in some species, as in Figs. 6G View FIGURE 6 , 19E View FIGURE 19 , 48I View FIGURE 48 and 64H View FIGURE 64 ), usually hook-shaped and sclerotized, and is either a single rod or split into two or even three parts ( Figs. 52H View FIGURE 52 , 61H View FIGURE 61 , 60H View FIGURE 60 and 27F View FIGURE 27 ); the embolus lies between the uncus and appendix, is soft and transparent ( Figs. 23H View FIGURE 23 , 34F View FIGURE 34 and 46H View FIGURE 46 ).

The legs are exceedingly long and slender, often characteristically annulated, femora with dark and pale apical rings, patellae entirely dark, tibiae with a dark proximal ring and dark and pale apical rings ( Saaristo 2001); with numerous hairs on legs, but apparently without spines, curved or vertical hairs; tarsi with several pseudosegmentations and capsulate tarsal organs ( Figs. 7B View FIGURE 7 , 18B View FIGURE 18 , 22E View FIGURE 22 and 34G View FIGURE 34 ). Male gonopore with four or five (few species) epiandrous spigots ( Figs. 7C View FIGURE 7 , 18C View FIGURE 18 , 22C View FIGURE 22 and 34H View FIGURE 34 ). Chinese species of Pholcus generally have elongate or globose abdomens, even both types of abdomen occurring in conspecific specimens; a few species with worm-shaped abdomens ( Figs. 39A View FIGURE 39 and 10E View FIGURE 10 ). Abdomen mostly grey, dorsally and laterally with distinctive blackish marks or spots ( Figs. 15C View FIGURE 15 , 2C View FIGURE 2 and 32C View FIGURE 32 ), but a few species without any dark spots ( Figs. 10E View FIGURE 10 and 56C View FIGURE 56 ). The male genital area with or without small brown marks, ventrally with long central brown lines or stripes posteriorly in some species, but others without dark patterns. The female genitalia are usually relatively simple externally, comprising a more or less elevated area divided by a simple slit into anterior and posterior plates ( Figs. 11A View FIGURE 11 , 16A View FIGURE 16 , 34A View FIGURE 34 and 53A View FIGURE 53 ); there may be special outgrowths (variably sclerotized apophyses, e.g. knob-, whip-, worm-, hook-, necktie-shaped in Figs. 54A View FIGURE 54 , 25A View FIGURE 25 , 16A View FIGURE 16 and 46A View FIGURE 46 , also called a ‘scape’ in some references) and pits on the anterior plate (also called ‘genital plate’), the posterior plate is also called ‘accessory plate’ ( Saaristo 2001). However, the internal morphology is very complicated ( Huber 1995; Uhl 1994) generally with a sclerotized arch anteriorly and a pair of pore plates posteriorly ( Figs. 5B View FIGURE 5 , 9B View FIGURE 9 , 14B View FIGURE 14 , 21B View FIGURE 21 and 26B View FIGURE 26 ).

The spiders of Pholcus have six spinnerets in three rows ( Figs. 18I View FIGURE 18 , 44F View FIGURE 44 , 50G View FIGURE 50 and 57G View FIGURE 57 ), anterior lateral spinnerets (ALS) each with one widened major ampullate gland spigot, one pointed conical spigot, and six piriform gland spigots ( Figs. 18J View FIGURE 18 , 22H View FIGURE 22 , 34B View FIGURE 34 , 44G View FIGURE 44 and 57H View FIGURE 57 ); posterior median spinnerets (PMS) with two spigots each ( Figs. 18K View FIGURE 18 , 22I View FIGURE 22 , 44H View FIGURE 44 , 57I View FIGURE 57 and 59I View FIGURE 59 ), one aciniform gland spigot, the other ampullate gland spigot; and the posterior lateral spinnerets (PLS) without any spigots ( Figs. 18L View FIGURE 18 and 44I View FIGURE 44 ).