| | The spider families of Britain and Ireland |
Comb-footed Spiders.
Morphology. The adult spiders 1–10 mm long; decidedly plump-bodied (mainly), or slender-bodied to of medium build (in some of the males); decidedly short-legged, or with legs of medium length, or decidedly long-legged (from shorter than the body to over three times as long); with eight eyes. The eyes in two horizontal rows of 4; all clear and glassy. The maxillae longer than broad. The palpal organs of the male of complex structure and enclosed by the specialized, hollowed tarsal segment (the cymbium). The male palps without a paracymbium. The female palps with a claw. Metatarsus IV of the females without a calamistrum. Tarsal claws 3. Tarsus IV with a ventral row of serrated bristles constituting a ‘comb’ (though this is indistinct in the males of some species). The abdomen conspicuously patterned dorsally (usually), or plain dorsally (e.g., in Dipoena inornata); sometimes exhibiting red or pink colour, but neither predominantly bright red and black nor predominantly bright red and yellow, or without any red coloration. The abdomen of the females without a cribellum. The reproductive openings of the females associated with an epigyne.
The adults making snare-webs; constructing tangled webs (usually, an irregular assemblage of criss-cross threads, in various situations), or constructing horizontal sheet webs (rarely).
Representation in Britain and Ireland. 52 species in Britain; in the genera Achaearanea, Anelosimus, Dipoena, Crustulina, Enoplagnatha, Episinus, Euryopis, Neottiura, Paidiscura, Pholcomma, Robertus, Simitidion, Steatoda, Theonoe, and Theridion.
Comments. The posterior margins of the chelicerae usually lack teeth, and the male palp lacks a well developed paracymbium, the latter being often represented by a small hook near the base of the cymbium. The labium is not usually swollen distally, but is sometimes so in Euryopis, Theonoe and Robertus.
The ‘False Widow’, Steatoda nobilis, native to Madeira and the Canary Islands but found in southern Britain since the Nineteenth Century, seems to be spreading northwards. It is very venomous, and can inflict a bite calling for immediate medical attention. Other members of the genus also sometimes bite humans, causing feverishness or general malaise.
Illustrations. • Achaearanea riparia and A. tepidariorum. 114, Achaearanea tepidariorum (C.L. Koch): a, female; b, male; c and d, two views of the palpus of the male; e, web and cocoons, with one of the latter removed and more enlarged. 115, Achaearanea riparia (Bl.): a, female; b, male; c, palpus of the male. From Blackwall (1864). • Achaearanea lunata. Achaearanea lunata (Clerck): a, female; b and c, varieties of the female; d, male; e, cocoons, in situ and one removed and enlarged. This is the Theridion sysyphum of Blackwall, which was interpreted as Theridion lunatum (Oliv.) by Bristowe, and referred to Achaearanea lunata by Platnick (20003). From Blackwall (1864). • Anelosimus vittatus, Dipoena inornata and Crustulina sticta. 122, Anelosimus vittatus (C.L. Koch): a, female; b, male; c, palpus of the male. 126, Crustulina sticta (Camb.). female. 127, Dipoena inornata (Camb.): a, female; b, male; c, palpus of the male; d, cephalothorax in profile. From Blackwall (1864). • Crustulina guttata and C. sticta. 126, Crustulina sticta (Camb.), female. 131, Crustulina guttata (Wider): a, female; b, male; c, the palpus of the male; d, the cephalothorax in dorsal view; e, the sternum. From Blackwall (1864). • Episinus angulatus and Euryopis flavomaculata. 132, Euryopis flavomaculata (C.L. Koch): a, female; b, male; c, palpus of the male. 133, Episinus angulatus (Bl.): a, female; b, male; c, palpus of the male. From Blackwall (1864). • Steatoda bipunctata and Steatoda phalerata. 112, Steatoda bipunctata (Linn.): a, female; b, male; c, palpus of the male. 135, Steatoda phalerata (Panzer): a, female; b, male; c and d, different views of the male palpus; e, cephalothrax from above; f, profile of the spider, showing the spines on the legs and cephalothorax; g, the abdomen in profile. From Blackwall (1864: 112 being his Theridion quadripunctatum, and 135 his T. signatum). • Enoplognatha ovata. Enoplognatha ovata (Clerck): a, female; b, male, c and d, varieties of the female; e, variety of the male; f, female in her suspended posture; g, cephalothorax and abdomen of female, in profile; h, cephalothorax from above, showing the location of the eyes; i, maxillae, labium and sternum; k, the chelicerae of the male; l, cocoon in situ; unlettered, the palpus of the male and the chelicerae of the female. From Blackwall (1864). Called by Blackwall Theridion lineatum, referred by Bristowe to Theridion redimitum Linn., and in Platnick's 2003 list to Enoplognatha ovata (Clerck). • Theridion sisyphium. Theridion sisyphium (Clerck): a, female; b, a variety of the female; c, male; d, palpus of the male; e, cocoon in situ on a leaf. From Blackwall (1864. Labelled by him T. nervosum, referred by Bristowe to T. notatum Linn., and to T. sisyphium by Platnick). • Theridion pictum. Theridion pictum (Walck.): a, female; b, male; c, palpus of the male; d, cocoons in situ. From Blackwall (1864). • Simitidion simile, Theridion cinctum and T. varians. 119, Simitidion simile (C.L. Koch): a, female; b, male; c and d, two views of the palpus of the male; e, underside of the abdomen of the female. 120, Theridion varians Hahn: a, female; b, male; c, palpus of the male; d, cocoons in situ. 121, Theridion tinctum (Walck.): a, female; b, male; c, palpus of the male. From Blackwall (1864). • Neottiura bimaculata and Steatoda grossa. 123, Neottiura bimaculata (Linn.): a, female with cocoon; b and c, varieties of the female; d, male; e, a dark variety of the male; f, female abdomen, in profile; g and h, different views of the palpus of the male. 124, Steatoda grossa (C.L. Koch), male, and (a) its palpus. From Blackwall (1864). • Paidiscura pallens, Theridion auratum and T. haematostigma. 125,Paidiscura pallens (Bl.): a, female; b, male; c, the palpus of the male; d and e, the cocoon, in situ and enlarged. 130, Theridion albens Bl., female (now regarded as a form of P. pallens). 128 and 128a: Theridion auratum Bl., female and detail of the eyes. 129 and 129a: Theridion haematostigma Bl., female and detail of the eyes. T. auratum and T. haematostigma were awarded the status "identity uncertain" by Bristowe, and are omitted from modern check lists. • Theridion sp.. Theridion sp.: a, female; b, male; c, a variety of the female; d, a variety of the male; e, the palpus of the male. From Blackwall (1864, under the name T. denticulatum Walcken. Representing either T. melanurum Hahn or T. mystaceum C.L. Koch, which are indistinguishable in this representation.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. The spider families of Britain and Ireland. Version: 5th August 2019. delta-intkey.com’.
