1"8 FIRST ANNUAL REPORT OF THE STATE ENTOMOLOGIST. 



THE BEE-KILLER — Trtipanea apivora, Fitch. 



(Diptera, Asilidae.) 



In the last chapter of his 9th Report, Dr. 

 Fitch describes a fly by the name of the "Ne- 

 i Bee-killer," which lie received from 

 Mr. R. O. Thompson, of Nursery Hill, Otoe 

 :ounty Nebraska, and which the latter named 

 gentleman had found preying upon the bee in 

 North Nebraska in the summer of 1864. Mr. 

 Thompson has since removed from Nebraska 

 to North Missouri, and in conversation with 

 him last summer he informed me that he had 

 met with this Bee-killer each year since 1864, and that it seemed to be 

 increasing. At a later day, in a communication to the Rural World of 

 September 12, 1868, he states that it made its appearance in such num- 

 bers in North Missouri last summer, that it to a great extent prevented 

 the bees from swarming. I present above at Figure 93 a life-size por- 

 t this voracious insect, its general color being yellowish-brown or 

 > .ish-gray. This figure will enable its ready recognition, and 



those who wish a very full and detailed description of it will find it 

 in the Report of Dr. Fitch above referred to. It belongs to the Asilus 

 of two winged flies which have been very aptly termed the 

 i lie insect world. Last Jwly I found thse flies quite common 

 iu . Shaw's beautiful gardens in St. Louis, and I watched them by 

 md found to my amazement that though other insects were 

 ail around, as well as other species of bees, yet they never 

 seized any other species but the common Honey-bee. They capture 

 e on the wing, pouncing upon it with lightning-like rapidity; 

 then grasping it securely with their fore legs, they alight upon some 

 or even upon the ground, and rapidly suck out the inside of the 

 bee, with the stout and powerful proboscis which is shown in the fig- 

 ure, leaving the empty shell when they get through. Mr. Thompson 

 beneath some favorable perch that is near the apiary, hun- 

 hese bee-shells may be found accumulated in a single day; 

 he has watched and found that a single fly on one of these 

 es destroyed no less than 141 bees in that period of time. 



The habits of these flies are little known, and until they are bet- 

 ter understood no feasible way of protecting the bees from their at- 

 be given. Those which are known to haunt the apiary 

 I be captured, and this can best be done by means of a net. It 

 is sible to catch them while on the wing, though as soon 



as they have settled with their prey they are caught with compara- 

 tive ease. It will pay to thus catch them for they are doubtless the 

 cause of much of the non-swarming which we hear of. 



