194 Forty- FIFTH Report ok the State Museum. 



Mr. A. J. Fly, of Delta, Oneida county, writes as follows: 



I write to you for information in regard to a, fly, which made its 

 appearance in these parts about a year ago, and is proving a source of 

 much d image to the dairymen and of suffering to the stock. The fly 

 his increase 1 very fast an 1 attacks the cattle in swarms, causing some- 

 times large, raw sores on the shoulders and by the root of the tail, and 

 also by the navel. They also cover the horns at times. They apparently 

 a.tack fat cattle as readily as those in poor flesh. White and light colored 

 «cattle do not seem to be as much attacked as the black or dark ones. 

 "■On spotted cattle the flies are sometimes thick on the black spots, while 

 i^there are hardly Siuy on the white. The fly seems more hardy than our 



• common one, and takes more to kill it. If tliere is anything that can 

 be done to get rid of this plague, our dairjanen would be glad to know 



ut, and avail themselves of the information, that they may relieve their 



• cattle which are suffering greatly day and night. 



The injuries from the attack of this fly do not result in the death of 

 the infested animals, as was first reported, but they occasion large sores 

 upon the body in various places, and from the irritation and inflamma- 

 tion that the myriad flies cause, there follows a great falling off in the 

 amount of milk given — variously estimated at from one-third to one- 

 .half. The cattle also lose materially in flesh. 



'In New Jersey it has been found that the fly was most troublesome 

 iin June and early July, and that after the middle of August it gave 



• comparatively little trouble. But even if you are to escape from any 

 TS^rious further liarm from it this year, you should d ) what you can to 



prevent its continued multiplication. 



Knowing that tlie fly deposits its eggs in the fresh droppings of the 

 cattle, and mostly during the night, and that it lives and matm-es 

 therein, I would urgently recommend that every morning, in infested 

 localities, these droppings be carefully and thinly spread in the fields, 

 so that it may quickly dry. The eggs and the larvae would die in the 

 <lry material and could not mature therein. Another metliod of killing 

 ithe insect in its early stages, but perhaps not so good as the preceding, 

 as to scatter lime over the fresh droppings. To prevent the flies from 

 J)iting the cattle, I know nothing better than once a week going over 

 -the bodies with a sponge dipped in whale-oil in which some carbolic 

 :acid has been mixed, only applying it to the tips of the hairs. I have 

 itreated of this fly, and given figures of it, in my Fifth Report on the 

 Insects of New York, 1889, pp. 220-227. Possibly you might make 

 some extracts from this, which would be serviceable and interesting to 

 so ne of your readers. 



Very truly yours. 



