168 SPIDERS 



of the web in the chelicerae, while heavier prey are carried on a 

 thread from the spinnerets and supported by a hind leg. When a 

 lifeless inedible object touches the web it is usually cut out and 

 allowed to fall to the ground, as are formidable and dangerous 

 insects such as wasps and bees, whereas suitable prey is bitten and 

 then wrapped up. The behaviour which follows the biting of a 

 distasteful insect is surprising: the spider makes its way, sometimes 

 clumsily as if in distress, to the edge of its web where it gets rid of 

 the distasteful liquid by pressing its mouth to the ground or 

 wiping it on a leaf. 



These brief descriptions of the methods employed by spiders 

 for the capture of prey by no means exhaust the list of ingenious 

 methods that have arisen in the course of evolution. The water 

 spider Argyroneta aquatica no longer uses its web to entrap its 

 prey, but hunts for small aquatic creatures which are eaten on dry 

 land or in its bell, while a South African spider builds a small snare 

 resembling a postage stamp in size and shape. The corners are 

 held by the spider's long legs. When an insect approaches, the web 

 is stretched to nearly five times its normal size and hurled over the 

 prey. There can be few developments more remarkable however 

 than that of certain Argiopidae in Australia and South Africa 

 {Dicrostichus magnificus and Cladomelea akermani) which emerge 

 at nightfall and whirl a thread weighted with a gummy globule 

 until this strikes some passing insect which is then hauled in. 



Enemies 



So far only one side of the picture has been considered. In 

 addition to the vast numbers killed as a result of unfavourable 

 climatic conditions, spiders are beset with enemies throughout 

 their lives. The infant mortality rate in particular is immense. 

 Baby spiders do not feed until they have digested all the yolk with 

 which the eggs from which they hatched were supplied, but after 

 their first moult the little spiderlings develop their typical canni- 

 balistic tendencies and many are eaten by their own kin. As 

 Warburton (1912) wrote: 'The case of the survivor of the Nancy 

 Bell in the Bab Ballads would be exceedingly commonplace in the 

 araneid world.' In addition to the numbers devoured by other 

 spiders, both of their own as well as of other species, spiders and 



