Dec, 1901.] Collecting Tabanidae. 167 



COLLECTING TABANID^. 



James S. Hine. 



The habits of flies belonging to the family Tabanidae, com- 

 monly called horse-flies or gad-flies, furnish much material for 

 stud}^ and observation. I take this opportunity to record some 

 of the notes which I have taken in the last few years while 

 endeavoring to collect and study the local species of the family. 

 Although the eggs, larvae and pupae of many species have been 

 studied, what I have to say in this paper pertains wholly to the 

 adults. Members of the family are usuallj- taken by every ento- 

 mologist who does general collecting, but as a usual thing males 

 are seldom taken; in fact this sex is so poorly repress. nted in 

 collections that no key has been published for identifying the 

 males of our American species. The student must use the ke}- 

 to the females as far as possible and guess at the rest. In A-ery 

 many cases the male is not even described, so that sometimes, 

 when the sexes are unlike, they can be associated only b}^ obser- 

 vations in the field. By careful collecting and observation we 

 have procured practically all of our local species in both sexes, 

 and the derived benefit, satisfaction and enjoyment have paid us 

 fully for our time and pains. 



In the first place the mouthparts of the two sexes are differ- 

 ent — the male lacks the mandibles which are present in the 

 female. This makes it necessary for them to procure their food 

 from different sources, the male obtains his from flowers, while 

 the female lives by puncturing the skin and sucking the blood of 

 warm-blooded vertebrates. Thus it is evident that during the 

 time spent in procuring food the sexes cannot remain together. 

 From an economic standpoint the female most concerns the 

 student and she is often taken for study without an attempt being 

 made to procure the male. 



At this point I can say collect females around horses, cattle and 

 other animals, and males on flowers ; but this is not enough, for 

 knowing the general habits of insects we are certain that there is 

 a common ground where the two sexes may be found together. 

 One finds this common ground in the vicinity of water, where 

 their transformations take place and where their eggs are laid, 

 also in various other places, which we shall take occavSion to dis- 

 cuss as we proceed. 



The females of all our local species of Chrysops with Tabanus 

 pumilus and nivosus come buzzing around the collector in num- 

 bers, and at such times may be taken easily with a net. Other 

 species of Tabanu.s come near enough that the sound of their 

 wings is recognizable, but are so active that it is almost impossi- 

 ble to procure them. 



