50 POULTRY DISEASES 



legged, sexual or adult state. The parasite multiplies very 

 fast in the warmer parts of the summer, July and August, 

 when conditions are more favorable for their propagation. 



Symptoms of Trombidium Infestation. — By means 

 of its conical mouth parts, referred to above, it 

 wounds the skin and sucks blood. The engorged 

 parasite is blue to red in color, depending 

 upon the quantity of blood taken into the digestive 

 tract. During the summer of 1911 the author 

 observed one infested flock of chickens in which 

 the affected birds showed symptoms similar to 

 birds infested with lice. They became unthrifty, 

 ceased laying, sitting hens deserted their nests, 

 all exhibited unkempt appearance of the feathers 

 and many died. Many were found dead under the 

 roosts of mornings. Examination of the nests, 

 roosts and birds revealed millions of the parasites. 

 This was in the month of August. 



Treatment: Eradication. — The same treatment as 

 for lice will be found verv effective. Absolute 

 cleanliness, plenty of kerosene repeatedly applied 

 to the roosts, air-slacked lime on the floors, and in 

 the bottom of the nests. 



Dermanyssus Gallinae 



Description. — By referring to Fig. 14 it will be seen that 

 the body of this parasite, commonly known as the mite 

 chigger, differs from the Trombidium holosericeum in that 

 it is ovopyriform in shape instead of oval. The diameter 

 of the posterior third is greater than that of the anterior 

 third. The abdomen and legs are provided with rather short 

 bristles. Its mouth parts are conical in shape and arranged 

 for injuring the skin and sucking blood. The color varies 

 according to the amount of blood contained within the in- 

 testinal tract, varying from yellow to a yellowish-red. The 

 free extremity of the legs is provided with an apparatus 

 which enables them to hold on or cling to objects and to move 

 about rapidly. 



Life History. The female, like the female of the preceding 



genus, lays her eggs in the cracks and crevices and filth of 

 the floors and nests, where they hatch out in a few days, if 

 the temperature be favorable. The young, six-legged asexual 



