The families of British spiders
Including Microphantidae (= Erigoninae).
Morphology. The adult spiders 1.5–3.5 mm long (Erigoninae), or 1.2–6(–7.2) mm long (Linyphiinae); decidedly short-legged (rarely), or with legs of medium length to decidedly long-legged (the Erigoninae being generally relatively short-legged, the Linyphiinae relatively long- and slender-legged, but the legs rarely more than three times the body length). The caput conspicuously lobed, turreted, or with globular swellings (in the males of some Erigoninae, sometimes spectacularly so, e.g. in Walckenaeria spp.), or not conspicuously ornamented with lobes, turrets or globular swellings. The adult spiders with eight eyes. The eyes basically in two horizontal rows of 4 (but in some Erigoninae the pattern is disturbed in that some of the eyes are elevated on lobes. This is spectacularly exemplified in males of Walckenaeria acuminata, where the the caput exhibits a slender elongation bearing the two pairs of medians on its tip, and the laterals on its slightly thickened mid-region); all clear and glassy. The maxillae variable in form, about as long as broad to shorter than broad. The palpal organs of the male of complex structure and enclosed by the specialized, hollowed tarsal segment (the cymbium). The male palps with a well developed paracymbium. The female palps with a claw (in Linyphiinae), or without a claw. Metatarsus IV of the females without a calamistrum. Tarsal claws 3. Tarsus IV without a ventral comb. The abdomen conspicuously patterned dorsally (in most Linyphiinae), or plain dorsally (in most Erigoninae). The abdomen of the females without a cribellum. The reproductive openings of the females associated with an epigyne.
The adults making snare-webs (conspicuously so in many Linyphiinae), or not making snare-webs (many Erigoninae seeming to be ground-running predators; numerous species of Linyphiidae are highly dispersive, being generally encountered wandering or ballooning rather than in webs); the web-formers constructing horizontal sheet webs (on the ground or in vegetation, those of Linyphiinae often large, but those of Erigoninae often small and perhaps not genuine snares).
British representation. About 270 species in Britain; in about 105 genera, e.g. Centromerus, Entelecara, Erigone, Lepthyphantes, Linyphia, Oedothorax, Porrhomma, Walckenaeria. The traditional tribes (Erigoninae, with about 58 genera) and Linyphiinae (about 46 genera), appear to reflect general morphological and behavioural trends, but have fallen into disfavour in recent times.
Comments. The labium is swollen distally, and the male palp bears a discrete chitinized paracymbium, which is variable in form and attached to the cymbium by a membrane. The chelicerae usually bear stridulating ridges, but have no lateral condyle, and their posterior margins exhibit one or more teeth. This family provides most of the ballooning species, and is responsible for adorning large areas of countryside with shimmering silken mantles.
Illustrations. • Labula, Lepthyphantes, Linyphia, Microlinyphia, Neriene. • Linyphia triangularis. • Neriene peltata and N. clathrata. • Megalepthyphantes nebulosus, Lepthyphantes tenuis, and L. zimmermanni. • Lephthyphantes minutus and L. obscurus. • Lephthyphantes alacris, L. ericaeus, and L. flavipes. • Drapetisca socialis and Bolyphantes luteolus. • Floronia bucculenta and Tapinopa longidens. • Kaestneria pullata?. • Bathyphantes gracilis and B. nigrinus. • Helophora insignis. • Centromerita bicolor. • Porrhomma errans and Porrhomma pygmaeum. • Microneta viaria and Meioneta rurestris. • Gnathonarium dentatum, Tiso vagans and Tmeticus affinis. • Hypomma bituberculatum and Hypomma cornutum. • Gongylidium rufipes. • Gongylidiellum vivum?. • Leptorhoptrum robustum. • Oedothorax apicatus. • Oedothorax fuscus and Oedothorax agrestis. • Oedothorax fuscus cf. O. agrestis, male palps. • Oedothorax gibbosus. • Dicymbium nigrum. • Gonatium rubellum and Gonatium rubens. • Hylyphantes graminicola and Sintula corniger. • Erigone atra or E. longipalpis?. • Poeciloneta variegata. • Macrargus rufus and Saaristoa abnormis. • Stemonyphantes lineatus. • Walckenaeria acuminata. • Walckenaeria cuspidata and Walckenaeria vigilax. • Walckenaeria monoceros and Walckenaeria unicornis. • Walckenaeria obtusa. • Leptothrix hardyi and Monocephalus fuscipes. • Entelecara flavipes and Pelecopsis parallela. • Lophomma punctatum. • Cnephalocotes obscurus. • Troxochrus scabriculus. • Erigonella hiemalis. • Dismodicus bifrons. • Baryphyma pratense. • Araeoncus humilis and Diplocephalus cristatus. • Diplocephalus picinus. • Ceratinella brevis. • Pelecopsis nemoralis and Trichopterna thorelli. • Peponocranium ludicrum. • Savignya frontata. • Trichoncus saxicolus. • Pocadicnemis pumila.
To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. The families of British spiders. Version: 4th January 2012. http://delta-intkey.com’.