Report of the State Entomologisi 333 



rapidly spreading northward, a few words in relation to it may serve 

 to give early knowledge of its presence, and thereby enable farmers 

 to meet it promptly and check its increase. 



The larger number of our most harmful insect pests have been 

 brought to us, from Europe, and this is one of the latest additions to 

 the extended list of much to be regretted importations that might be 

 given. It is native to the south of France — was first noticed in 

 Pennsylvania in 1886, and from its habit of collecting in masses on 

 the horns of cattle so as completely to cover and blacken them toward 

 their base, it has been given the common name of the " cow-horn lly," 

 Other names that have been applied to it, are "cow-fly," " horn-lly," 

 " Texan-fly," and " Buffalo-fly." Scientifically it is Hcematohia serrata 

 R. Desv. It is a small insect, not so large as the common house-fly 

 but resembling it in general appearance, and is quite closely allied to 

 the common biting fly, Stomoxys calcitrans, which often greatly 

 annoys cattle and horses by inflicting its sharp bite, usually upon 

 their legs. Unlike that, however, this confines its attack to cattle, not 

 extending it to horses, mules, or man. Greatly exaggerated state- 

 ments were at first made of the injury wrought by the fly. Common 

 report represented it as depositing eggs at the base of the horn, the 

 larvae hatching from which burrowed into the head, entering the 

 brain, and often causing the death of the animal within twenty-four 

 hours. 



As soon as scientific study could be given the insect, it was found 

 that the harm resulting from the presence of the fly was not so serious 

 as to be the occasion of alarm. No deaths had resulted from it, and 

 the cows were not dehorned by it. In the thinner-skinned and more 

 sensitive animals, as the Jerseys, the bites, and bloodsucking and 

 resulting inflammation might, perhaps, through rubbing, produce 

 sore and bleeding spots. The amount of harm caused by the fly 

 seems to be narrowing down to a falling off in the amount of milk 

 and cream of infested herds, reported by some at one-third, and in 

 one instance, in New Jersey, at one-half of the usual production. 



The life-history of the fly has been studied out, and published, by 

 the Division of Entomology at Washington,* and by Prof. J. B. Smith, 

 of the State Agricultural College of New Jersey. Its eggs are 

 deposited in the fresh droppings of the cattle. The larvae, feeding 

 and maturing therein, may be destroyed by a daily sprinkling of the 

 droppings with lime, or better still, as not liberating the ammonia, 

 with plaster. Protection from the bite may be had by the application 

 of oils to the body of the animals. 



* Insect Life, ii, 1889, pp. 93-103, fles. 11-15 ; RepoH U. S. Dept. Agriculture for 1889, p. 346. 



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