. Animal parasites and human disease. Medical parasitology; Insects as carriers of disease. CHIGGER 419. protruding end of the abdomen. Sometimes the entire female is expelled with her eggs by the pressure of the inflamed tissue which surrounds her. The eggs, which fall to the ground, soon hatch into typical flea larvse (Fig. 185). These, if they happen to fall on sandy soil under conditions suitable for their development, grow to maturity, pupate in a cocoon and emerge as adult insects in the course of ten days or two weeks. Fig. 184. Chigger or burrowing flea, Der- The wounds made bv the ™&l
. Animal parasites and human disease. Medical parasitology; Insects as carriers of disease. CHIGGER 419. protruding end of the abdomen. Sometimes the entire female is expelled with her eggs by the pressure of the inflamed tissue which surrounds her. The eggs, which fall to the ground, soon hatch into typical flea larvse (Fig. 185). These, if they happen to fall on sandy soil under conditions suitable for their development, grow to maturity, pupate in a cocoon and emerge as adult insects in the course of ten days or two weeks. Fig. 184. Chigger or burrowing flea, Der- The wounds made bv the ™<''^<'pMm« penetrans, gravid female. X 18. , . 1 • ,, , . (After Moniez.) burrowmg female in the skin become much inflamed and very painful. Frequently the dis- tended abdomen of a flea is crushed and the eggs released in the wound. In such cases the inflammation is greatly increased un- less the crushed body and eggs are immediately expelled. As soon as the eggs are laid, or even before, the skin surrounding the wound ulcerates and pus is formed. The empty female flea is ex- pelled. The sore which is left is very liable to infection by bac- teria and frequently results in the loss of toes or even whole limbs through blood-poisoning. Quiros has recently pointed out that in Central America, where chigger infection is very common, especially in boys who play barefooted in the streets along which infected hogs are driven to public market, deaths from tetanus and gas gangrene from chigger wounds are very common. Although usually only a few chiggers are present at a time, there are cases where hundreds infest a person at once, literally honeycombing the skin and making the feet or other parts of the body so sore that the victim is rendered a complete invalid. This obnoxious flea formerly existed only in the tropical por- tions of America, especially in the West Indies, but it was intro- duced to the West Coast of Africa in 1872, and has since become abundant throughout the
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