[83] Report of the State Entomologist. 225 



" In my observation in a pasture-field this morning I found a lot of 

 horn-fly eggs on manure dropped last night and this a. m. — only on 

 droppings that were in the shade. The eggs were scattered over the 

 top and not buried in the manure as those of other cow-flies, and 

 which, I think, prefer the sun." 



A number of the eggs thus found were sent me on different occa- 

 sions, upon their bedding, but they could not be recognized when 

 received, nor were larvae from them found within. Two other species 

 of Muscidce were obtained from the masses, about fifteen days after 

 reception, but no examples of the horn-fl3\ Others have experienced 

 the same difiiculty in attemj)ts to rear the species. 



Some other statements of habits, etc., contained in Mr. Boder's 

 letters, are these : 



Not one in fifty of the flies appear to be blood-suckers, judging from 

 their actions by daytime, and, also, by crushing them fresh from the 

 cow. Those that are blood-suckers also bite at night the cattle that 

 are left out all night. For the past month (August), a portion of the 

 flies have come to stall with the cows that are stalled all night. 



It may be prejudice, but from my view, our common cow-fly [Stomoxys 

 calcitrans], for biting, beats this new pest twenty to one in worrying 

 the cows. 



The fly subsists on the loose, soft part of the horn, near the head, 

 and also, apparently, on the hair or dandruff, or both. [We can not 

 imagine what operation of the fly has been mistaken for this feeding, 

 for it is known that its mouth-parts — even of the male, which probably 

 does not subsist on blood — are entirely unfitted for taking other than 

 liquid food]. 



Heavy rains seem to be unfavorable to the production of the fly — 

 perhaps through destroying its eggs. Ants and beetles of several 

 kinds explore every piece of the droppings favorable, and apparently 

 destroy milHons of the maggots. 



As these pages are about being handed to the printer, the gratify- 

 ing information is received from Mr. Howard, of the Entomological 

 Division at Washington, that they have secured full notes of the 

 insect, have traced every stage of its life-history and have had a 

 number of illustrations made, which will be published either in the 

 Annual Report of the Entomologist, or earlier in Insect Life. 



The Injury to Cattle. 

 The nature of the injury caused to cattle, from the attack of this fly, 

 and its extent, has been so ably summarized by Prof. Smith that we 

 copy the following from his paper cited, as best covering our present 

 knowledge on the subject: 



When many of these flies are at the cattle, of course the pain caused 

 by the poisoned punctures is almost incessant; the cattle throw their 

 heads about, lash their tails, and in every way try to get rid of their 



