40 ANIMALS OF LAND AND SEA 



diseases, especially of anthrax, which sometimes attacks man. 

 In Africa deer-flies act as carriers of a parasitic worm known 

 as a loa which creeps under the human skin. When tabanids 

 occur in great numbers, as many species often do, their attacks 

 are sometimes fatal. 



Often mistaken for the house-fly because of its similar size 

 and color is the stable-fly which, Hke its various close rela- 

 tives, has blood-sucking habits. This fly, unlike most other 

 blood-sucking flies, prefers to bite through clothing, stockings 

 particularly. Its maggots mostly feed in decomposing vege- 

 table material, but sometimes breed in manure like house-flies. 

 Both sexes bite, and they are able to transmit anthrax and 

 probably other diseases. 



The psychodid or phlebotomous flies, in the orient commonly 

 called sand-flies, of many species, are small, but have a very 

 painful bite. The larvae live in cracks and chinks feeding on 

 vegetable material. Usually only the females bite. Some spe- 

 cies disseminate phlebotomous or three days' fever, and they 

 have been accused of carrying oriental sore and other illnesses. 



The biting midges, the smallest of the biting flies, are known 

 to everyone as sand-flies, punkies or no-see-ums. Though 

 very small, their bite is quite annoying, and they often occur 

 in numbers. The young live in water or in moist places, some 

 in sea water. Only the females bite, mostly toward evening 

 or in the early morning, and especially when the air is very 

 still. On the island of Mayreau a few miles from St. Vincent 

 I once constructed a duck blind on the shore of a shallow 

 pond. But it was not possible to use this blind at all on ac- 

 count of the numbers of these flies which in the early morning 

 and towards evening quite drove one frantic. Some of these 

 flies have been supposed to carry a form of oriental sore. 



The three species of lice or "cooties" which live exclusively 

 on man each on a different part of the body have been much 

 discussed in recent years. Tjqphus, trench fever and relapsing 

 fever are carried by these insects, which possibly carry also 

 other illnesses. 



