Flytraps and Their Operation H 



on either side it is folded inward nearly to the center of the frame 

 in V-shaped folds running; lono;itudinally across the window. One, 

 tAvo, or even more folds may be made in the screen on either side. 

 The upper side of the fold // should extend toward the center almost 

 at right ang^les with the side of the trap — that is, parallel with the 

 top and bottom; and the lower side C should slant downward as 

 shown in the drawing. The sides of the frame may be cut out at 

 the proper angle and the pieces D returned after the screen has been 

 tacked along the edges. Along the apex (inner edge) of each fold is 

 punched a series of holes E about one-half inch in diameter and 1 

 inch apart. The apices of the folds on either side of the window 

 should not be directly opposite. A narrow door F opening down- 

 ward on hinges should be made on one side of the trap at the bottom 

 for removal of the dead flies. The entire trap is fastened to the win- 

 dow by hooks so that it may be readily taken off. An additional 

 trapping feature may be added by providing a tent trap fitted in the 

 bottom of the box. A narrow slit is left along the base to allow the 

 flies to enter beneath the tent. Bait may be placed under the tent to 

 attract the flies. 



It has been found that the use of these window traps will aid in 

 protecting animals in barns from stable flies and mosquitoes, and in 

 some cases horseflies and other noxious species are caught. They 

 tend to exclude the light, however, and are somewhat cumbersome, 

 especially in thin-walled buildings. 



TRAPPING THE SCREW-WORM FLY^ 



Recent efforts to reduce the loss to the livestock industry of the 

 Southwest resulting from the ravages of the screw-worm have di- 

 rected attention to the employment of flytraps in this w^ork. 



Mention has been made of the importance of preventing the breed- 

 ing of flies as a prerequisite to effective control. This is equally true 

 of the screw-worm and other blowflies, which attack animals, and of 

 the house fly. In the case of these blowflies main dependence must 

 be placed on the complete and prompt burning of all carcasses and 

 animal refuse. 



Experiments conducted in the range sections of Texas indicate 

 that traps properly baited and set are of material aid in preventing 

 screw-worm injury to livestock. It is advised that at least one trap 

 be maintained on each section of land. These should be located pref- 

 erably near watering places and where cattle congregate, especially 

 in the so-called hospital traps, where the screw-worm-infested 

 animals are kept for treatment. 



The conical-type traps as described are advised. The traps should 

 be set on a board platform about 2 feet square, securely fastened to a 

 tree or on a post where the trap and bait will be the least disturbed 

 by stock or wild animals. 



During the latter half of one season over 100 gallons of flies, the 

 vast majority of which were screw-worm flies, were captured in 

 about 25 traps operated on a ranch in west Texas. 



The question of the baits best adapted for this species and other 

 points in regard to the operation of the traps are briefly discussed 

 under subsequent headings. 



^ Chrynomi/a maceUaria, Fab. 



