PARASITOT.OGY. 47 



THE ACARI. 



Dermanyssus Gallinae (Derma — skin; gallus — acock). 



Sy7io?iym. — Chicken mite. 



History. — Universally found in hen-houses. 



Description. — They are very small, as the word 

 "mite" indicates. The body is ovi-pyriform in snape 

 and broadest through the posterior third. The pierc- 

 ing stylet is cone shaped, and on either side is a 

 rounded palpus. The color of the body is yellowish 

 red, depending on the amount of blood contained in 

 the digestive tract. The legs are arranged on the 

 anterior half of the body. 



Animals Infested. — Birds. 



Co7iditio7i Produced.— They attack the birds in 

 large numbers, piercing the skin and sucking the 

 blood, and produce great irritation (pruritus). They 

 may even ^cause death of the host. Infested set- 

 ting hens may leave their nests. The parasites hide 

 in the nests, and cracks and crevices of the building. 

 If the nests are in the same building with horses or 

 cattle, or if the birds so infested roost in the Srtable 

 with larger animals, the mites may become tempo- 

 rary parasites of the larger animals, causing pruritus 

 and scratching, rubbing, rough coat, etc. 



Treatment. — Roosts, nests and buildings should be 

 w^hitewashed with limewater to which has been add- 

 ed creolin or kreso. The roosts should be drenched 

 with kerosene. Pyrethrum and sulphur, equal parts, 

 may be sprinkled in the nests two or three times a 

 week. 



Tromridium Holosericeum (Trombos — harvest) 



(holo — whole ) 



