REPORT OF THE ENTOMOLOGIST AND BOTANIST. 



185 



LIV^E STOCK. 



THE HORN- FLY 

 (Hcematobia serrata, Eob-Desv.). 



On page 144 of my last year's report I referred to a new cattle pest which had 

 appeared in Canada for the first time in the summer of 1892. This was the Cattle 

 Horn-fly, Hceinatobia serrata, of which an enlarged representation is given here- 

 with. The perfect insect is shaped much 

 like the Common Cattle-fly or the House- 

 fly, but is smaller and slighter, being only 

 one-sixth of an inch in length, that is, one- 

 third the size of those insects. The colour 

 is dark graj' with a yellowish sheen, and 

 the body is covered with short black 

 bristles. The head consists almost entirely 

 of the dark-red silver-edged eyes, but bears 

 on its lower surface the black dagger- 

 shaped tongue which is the cause of so 

 much torture to cattle. When not in use 

 this organ is carried projecting in front of 

 the head. This pest will be at once distin- 

 guished from the ordinary Cattle-fly by its 

 smaller size, greater activity and a char- 

 acteristic habit of gathering in clusters 

 upon the horns of cattle, for which reason 

 Fig. 26.— The Hom-Hy. Enlarged. it is now generally known as the Horn-fly. 



It is also for some unaccountable reason often referred to as the " Texas fly." This 

 is only the second year since it first appeared in Canada, but it has increased and 

 spread so quickly, that it has produced great consternation among cattle owners. 

 The frequent assertion that the flies or the maggots have caused the death of cattle 

 by boring into the horns, head or body, is entirely inaccurate: the whole injury is 

 due to the bites of the fly ; however, the irritation from this cause is in many cases 

 80 great that animals fall off" rapidly both in flesh and yield of milk. 



The life history is briefly as follows : — The matui'e flies appear early in spring 

 and lay their eggs upon the fresh droppings of cattle. These soon hatch and the 

 maggots live in the dung while it is in a moist condition. They then turn to pupae 

 in or beneath the dung, and the flies again appear within two or three weeks from 

 the time the eggs were laid. There can thus be several broods in a season. 



The enormous increase and rapid spread of this insect throughout the provinces 

 of Ontario and Quebec caused naturally enough, as stated, great consternation among 

 stock owners and dairymen. In many districts the loss was most serious, and I 

 have been informed by cheese-makers that during July in the several districts the 

 amount of milk supplied by their patrons was reduced at least to half the quantit}- 

 it would have been, but for these pests. A large number of letters were received 

 asking for remedies. The following are selected to show how severe the injuries 

 were, although from what I have been told at farmers' meetings, these do not at all 

 indicate the real extent of the loss in many districts of both Provinces. 



" July 18. — Will you kindly send me recipe for the fly pest on cattle ? The 

 milk has gone down tremendously in this section during the past week owing to 

 the flies." — Ogden Hinch, Napanee, Ont. 



"July 30. — The horn-fly is playing the mischief hereabouts and we must take 

 prompt measures to fight the pest and minimize the loss it is entailing. The falling 

 off in milk production within a week has been about 25 per cent, in spite of the fact 



