Gad Flies Hibernating under the Skin. 8i 



This produces great irritation and emaciation and not in- 

 frequently death (Bonssingault). 



Dermatobia Cuniculi. This is found in the Middle and 

 Southern States, the giant larva hibernating under the skin of 

 the rabbit, hare, gopher and opossum. 



Gadding of Cattle. From the time of Virgil ''gadding'' has 

 been attributed to the attacks of the hypoderma. So sensitive 

 are cattle to the fly that, in districts where it prevails, it is only 

 necessary to enter the field and make a persistent buzzing sound 

 to start the cattle, v?ith heads and tails in the air, at full gallop for 

 the nearest water. As the fly can neither bite nor sting it has 

 been denied that this particular fly is the cause of dread, and yet 

 the experience with the reindeer, the sheep and the horse, gives 

 color to Virgil's opinion. 



Symptoms. The first symptom of the hypoderma is the erec- 

 tion of the hair ( ' ' lick' ' ) over a small tumor on the back or else- 

 where. At this date (in winter or early spring) no opening can be 

 found in the tumor, but later a round hole is formed in the centre, 

 which gradually enlarges and through this the grub finally makes 

 its exit. The tumors known as warbles, wormils or wurnils, 

 may vary in size from a large acorn to a walnut. They are at 

 first hot and tender or itchy, but after the orifice has been formed, 

 in late winter and spring they usually .show little irritation. Yet 

 each is the seat of suppuration which serves to support the im- 

 prisoned larva, and when numerous they cause emaciation and 

 unthriftiness. The loss of $5 per head is claimed in England, and 

 among dairy cows as much as $15 per head. The loss on hides 

 is also considerable, the.se being depreciated in ratio with the 

 number of holes, or up to half their value in bad cases. The 

 hides from the countries that are hot and damp, and from those 

 with much brush and foliage are usually the worst. Those from 

 North Africa, India and China, are greatly deteriorated, and 

 those from Australia, South Africa, and South and North 

 America much less so. 



Treatment. The most important step is to go over all the 

 cattle in winter or early spring, squeezing out the grubs and 

 crushing them so that the stock of flies for the coming summer 

 may be cut ofE. If this practice could be made universal a whole 

 country could be speedily cleared of the pest, and there would 

 6 



