EXTERNAL PARASITES 



75 



cate once it has become established in a flock. It is due to a 

 scab parasite called Cytodites nuclus, synonyms for which 

 are: Cijtoleichus sarcoptides, Cnemidocoptes mutans, and air- 

 sac mite. 



Cytodites Nudus 



Description. — The body of this parasite is ovoid in shape as 

 illustrated in Fig. 29. It is whitish in color and is provided with 

 conical-shaped mouth parts, through which it sucks fluids from the 

 parts infested. The legs are rather short, conical, and in both 

 male and female all are provided with suckers, which aid in moving 

 about and in holding on. The legs are composed of five articles 

 (segments or joints) each. The larva has three pairs of legs 

 and the adult four pairs. 



Life History. — The ovigerous female lays eggs, as a rule, but at 

 times has been observed to deposit eggs ready to hatch and even 

 young larvae. The larvae pass through changes similar to those 

 of the scaly-leg mite by moulting several times, and finally reaching 

 the adult or sexually developed stage. 



Symptoms. — The air sac mite inhabits the al)dominal air 

 sacs, the air spaces of bones, and the air cells (alveoli) of the 

 luno's of chickens and pii^eons. If 

 only a few parasites are present no 

 symptoms may be noticeable, but if 

 they exist in large numbers their ef- 

 fects may be serious. The bird will 

 become thin in flesh and even emaci- 

 ated, will appear dull, stay apart from 

 the others of the flock, and the comb 

 will usually be pale in color. The 

 wings will droop and there will be 

 labored (heavy, difficult) breathing. 

 Coughing may occur and a rattling of 

 mucus (rales) in the trachea or bronchi 

 may often be heard. 



Postmortem Appearances. — By a 

 careful examination of the infested 



air sacs or the bronchi and sacules of the lungs, the mites 

 may be found appearing as minnte white specks, about the 

 size of the scaly leg parasites. 



For the specimen from which the accompanying drawing 

 (Fig. 29) was made, the author is indebted to Dr. W. B. 

 ^lack. Reno, Nevada, who olitained it from a flock of birds 

 examined in New York. Besides the white specks moving on 

 the surfaces of the air sacs, whitish-yellow ]~)oints. due to the 

 irritation caused by the parasite, may be found. The bronchi 

 may be congested. In severe cases inflammation or bronchitis, 

 and even pneumonia, may exist. 



The air-sac mite has also been reported as infesting the 



Fig. 



a, 

 rum ; 

 rum. 



29. Cytodites Nudus. 



rostrum; b, ambulac- 

 c, pedicle of ambulac- 



