172 SPIDERS 



(1953) has reviewed the subject of hearing and stridulation in 

 spiders. He concludes that vibrations of the air are perceived, so 

 spiders must possess a real faculty of hearing. 



In conclusion, it should be remembered that of the enemies of 

 spiders, man is in the first rank not only on account of the numbers 

 destroyed by insecticides and in agriculture, but also for the num- 

 bers eaten by primitive peoples in all parts of the world. In Siam 

 for example the Laos eat two different types, the giant orb webbed 

 Nephila spp. and the large hairy Mygalomorpha. The former are 

 known by a Siamese name that means *the golden one'. When 

 roasted and dipped in salt the abdomen, which is the only part 

 eaten, has a flavour of raw potato and lettuce mixed. Mygalo- 

 morpha are even more highly prized: their chelicerae are pulled 

 out and the spiders are roasted on sticks which removes the hair, 

 and then eaten with salt. Incidentally the hairs of these Mygalo- 

 morph spiders can cause very great discomfort, and if the face is 

 touched after stroking one of these creatures, sight may even be 

 endangered. On the other hand the bites of giant bird-eating 

 Mygalomorpha are usually not serious. Far more dangerous are 

 some of the Ctenizidae, and the spiders of the genus Latrodectus 

 such as L. mactans, the notorious 'black widow' of North America, 

 whose bite causes agonising pain that develops and spreads within 

 a quarter of an hour. This is often accompanied by profuse sweating, 

 difficulty in breathing, vomiting, prostration, convulsions and num- 

 erous other effects. Drop for drop the poison is said to be more 

 virulent than that of the rattlesnake, but the amount injected by the 

 spider is small and variable: death has occurred in about 5 % of known 

 cases of bites, but this figure is probably misleading as many cases 

 are never recorded or diagnosed (Thorp and Woodson, 1945). The 

 food of the 'black widow' includes very tough and resistant beetles 

 and it has been suggested that the virulent toxicity of its venom 

 may be correlated with the tough nature of its prey. 



Mating habits 



Spiders are nearly always on the offensive and are ready to kill 

 and eat most animals of suitable size that come within range. They 

 are mveterate cannibals, so it is obvious that mating must be a 

 hazardous undertaking fraught with real danger, particularly to the 



