PLEAS. 



21 



chickens hatched having been reported lost on account of the fleas. 

 In many cases young chickens, turkeys, and ducks have a combined 

 infestation of sticktight fleas and biting lice, and each contributes to 

 the worriment and weakening of the fowls. A few cases of death 

 observed among grown chickens apparently have been due to fleas. 

 In these instances not only the heads and necks of the chickens were 

 largely covered but numerous patches thickly set with fleas existed 

 under the wings and on the breast. The fowls heavily attacked be- 

 come droopy, lose appetite, and fall off in weight. Mild infestations on 

 grown fowls cause no marked injury, but no doubt egg laying is influ- 

 enced to some extent, and certainly infested fowls are unsightly. 



The fleas are present on hosts throughout the year, but they are 

 usually more nu- 

 merous in the sum- 

 mer and fall. The 

 species appears to 

 thrive best in ill- 

 kept chicken houses, 

 where chickens roost 

 under buildings, and 

 where dogs and cats 

 have their beds 

 closely associated 

 with the poultry. 

 This point will be 

 discussed further 

 under the general 

 topic of control. The 

 eggs are dropped by 

 the females while at- 

 tached to the host. 

 These fall beneath 

 the roost, hatch, and the young larvae feed on the excrement of the 

 parent fleas and on other animal and vegetable refuse. 



The species is one of the smallest fleas in this country and very 

 dark brown in color. The body is comparatively short and deep, and 

 the legs are slender, but the mouth parts are large and strong. The 

 male is usually slightly smaller than the female (fig. 8), almost 

 black, and is more frequently seen moving about on the host than the 

 female. 



THE CHIGOE FLEA. 



The flea commonly known as the chigoe or " jigger " (Dermatophilus 

 penetrans L.) 1 is related to the sticktight flea, but has different 



Pig. 8. — The sticktight flea : Adult female. 

 (Original.) 



Much enlarged. 



1 This should not be confused with the " chigger " or harvest mite, which is the larval 

 form of Trombidium. 



