FLEAS 149 



There is another flea (Rhynchoprion penetrans) with 

 peculiar habits and variously known as the " jigger," 

 "jigger flea," "chigoe," and "chique," that occurs in 

 tropical and subtropical America. It attacks man and 

 causes much annoyance and serious injury. It is also 

 found on the dog, cat, sheep, goat, cattle, horses, asses, 

 mules, and even birds. 



The adult female, after impregnation, burrows into the 

 flesh of the host, especially under the toe nails. Here, 

 the presence of the flea causes swelling and finally ulcera- 

 tion that sometimes becomes very serious in its final 

 effects. 



The hen flea, Argopsylla gallinacea, occasionally passes 

 to man as a temporary host. 



THE LIFE HISTORY OF FLEAS 



The life history of a flea is similar to that of a house-fly 

 in that there are four distinct stages during the full de- 

 velopment of a flea, namely, egg, larva, pupa, and adult. 



A flea does not pass its whole life history on the host 

 which it infests. Only the mature stage or adult is found 

 on the infested animal, the other stages being spent in 

 quite different situations. 



The eggs of the dog and cat flea are deposited, as a rule, 

 while the insect is on the body of the host. It is probable 

 that in many instances the eggs are deposited on floors, 

 carpets, or cloths upon which the dog or cat may be walk- 

 ing or lying. If laid while the parent flea is on the host, 

 they are not attached permanently to the hairs and do not 

 remain on the body of the dog or cat, but quickly fall off. 

 There are usually numbers of eggs around the spot where 



