LonsiAX \ ( 'IRCILAU \o. ('). 33- 



building at Cameron when the screens were left, open at the 

 time of day when they were Hyiiiiz'; ;md Air. .M. \V. McCall 

 s'ated lie had noticed the same thinu in previous years. The. 

 t! ree spe MCS eonntion at ( 1 ameron are Tuh<in.ns lineola (lined 

 horsefly), T. 5-maculatus, and T. coxhilis < irreen-head horsefly), 

 and are the ones upon which my observations were made. 

 The Station building is much the largest building in the 

 locality, is constructed in the form of a cross and is painted 

 * clear white. I have never fully satisfied myself as to the 

 ivason for this strange behavior of the flies, for there may be 

 two or three reasons for it. They may be attracted by the white 

 color of the building, or by the shade which it affords, or they 

 may possibly enter it through a desire to secure protection from 

 their enemies. The flies that entered a doorway, about 5x7 feet r 

 Li five hours' time, on August 23, when killed nearly filled a 

 quart measure, and almost all of them were females. This 

 observation suggested that a trap might be constructed that 

 would accomplish similar results, and accordingly, in 1905, the 

 ti ap was built, but by the time it was ready the horseflies were 

 almost gone and did not appear in sufficient numbers again 

 while I was in that locality to give me an opportunity to observe 

 its workings. 



While preparing a paper on the Tabanidie of Ohio, 

 it was suggested that, since many horseflies lay their eggs over 

 water, and also since the larvae from these eggs must drop into 

 the water when they hatch, kerosene on the surface of the water 

 might be used to kill these immature forms, and a measure 

 of success was obtained when the oil was used on stagnant ponds. 



Since, as shown above, various species are very uniform 

 i:i placing their eggs, there may be linns when a systematic 

 gathering of these will give practical results. It is often possi- 

 ble to find places where as many as 60,000 may be gathered in 

 a single hour. This would be practical, if at all. in a con' 

 where there is only once in a gre?it while a place for these flie> 

 t oviposit. 



