22 BULLETIN 248, U. S. DEPARTMENT OF AGRICULTURE. 



habits. Instead of remaining attached to the surface of the host, 

 the female, after being fertilized, burrows into the flesh until it 

 may become completely embedded. When it first reaches a host it 

 feeds much as does the sticktight flea, the burrowing tendency be- 

 coming evident only when the eggs are developing. A number of 

 hosts are attacked, particularly the hog. Cats, dogs, cattle, sheep, 

 horses, and even birds are attacked, but attention has been directed 

 to the species largely through its infestation of man. Its attack is 

 usually confined to the feet of the host, and in man particularly to 

 the toes. The females may enter between the toes or under the toe- 

 nails, and severe inflammation often follows, with the formation of 

 ulcers, frequently resulting in permanent crippling. While in the 

 host the eggs develop within the female and the abdomen becomes 

 greatly distended, often attaining the size of a small pea. The legs 

 of this species are not large, and when this distention takes place 

 they, as well as the head, become very inconspicuous. 



The eggs are deposited while the flea is attached and may drop 

 from the wound or pass out with the detached flea. So far as known 

 the rest of the life history is similar to that of other species. 



The chigoe is not known to be established in the United States, 

 although it has been reported on a few occasions from Florida. It is a 

 troublesome pest in the West Indies, in parts of Mexico, and in much 

 of South America. It is native to the American Tropics, but about 

 1872 it was introduced into western Africa. The African conditions 

 were favorable for the pest, and it soon became established in east 

 Africa and Madagascar and spread to the interior of the continent. 

 It was introduced more recently into India, but it appears to have 

 spread very slowly there. 



Conditions in Florida and southern Texas would seem to be favor- 

 able for this insect, and if care is not exercised it may be introduced 

 and become established in this country. 



NATURAL CONTROL. 



As has been stated, hot, dry weather is detrimental to flea develop- 

 ment. Likewise excessive moisture in a breeding place destroys the 

 immature stages. The direct rays of the sun in summer are important 

 in reducing the length of life of the adult flea and destroying the 

 immature stages. It is possible to take advantage of these natural 

 factors to a considerable extent in fighting the pest, as is brought 

 out later. 



Little is known of the natural enemies of fleas. Certain short- 

 winged beetles termed staphylinids are known to prey upon the adult 

 fleas, and certain species of mites have commonly been found upon 

 them. In Texas ants have been observed to prey upon the eggs and 



