SPIDERS 163 



closed tube. When insects crawl on this, the spider seizes them 

 from within and pulls them through the silk. The closed purse- 

 web of this species clearly restricts its diet to crawling insects, 

 worms and woodlice, whereas the orb webs of the Argiopidae 

 are adapted to the capture of insects in flight. A parallel amongst 

 hunting spiders is afforded by Dysdera erythrina or Drassodes 

 lapidosus, which hunt mainly under stones or at the roots of her- 

 bage at night, whilst the flower-living habit of Misumena vatia and 

 Thomisius onustus bring them into contact with winged insects. 



Protective flavours have been evolved by many invertebrates 

 which tend to render them distasteful to spiders. At least some 

 species avoid earwigs, stoneflies, caddis flies, moths, beetles, bugs, 

 ants and other Hymenoptera, harvest-spiders, mites, woodlice and 

 millipedes, and many of these have developed warning movements 

 since neither aposematic nor protective coloration are of any avail 

 against spiders that respond to tactile rather than visual stimuli. 



Although invertebrate animals, particularly Arthropoda, form 

 the bulk of the diet of spiders, there are a number of records of 

 vertebrates being eaten. As already mentioned some semi-aquatic 

 Lycosidae and Pisauridae may catch fishes, while amphibia, lizards, 

 young snakes, birds and small mammals not infrequently form the 

 prey of larger spiders, especially the Theraphosidae. The subject 

 has been reviewed by Millot (1943), to whom the reader is referred 

 for further details . 



Spiders are adapted to various habitats within which some 

 attack large insects, others capture smaller kinds: some spiders 

 attack diurnal insects, others hunt by night; some specialise in 

 crawling insects, others in those that fly. Bristowe(1941)* discusses 

 the means employed for the capture of prey and on this basis 

 divides the various families into hunting spiders, tube builders, 

 sheet- web builders, builders of scaffolding webs, meshed webs and 

 orb webs. 



Some hunting spiders seek their prey by day, trusting to their 

 good sight, while others are active at night and depend mainly on 

 the sense of touch. Jumping spiders (Salticidae) have the keenest 

 sight of all and stalk their prey from afar. Our commonest species, 

 Salticus scenicus, provides a convenient example of the group. 

 Equally at home on a perpendicular surface or on the underside of a 



