Prof. C. F. Hodge has designed a trap which is really a modified tent trap adapted to use in a window. This trap is constructed so as to catch the flies as they enter or leave through the window. It is adaptable to barns which are fairly free from cracks or other places where flies may enter. It may also be used on windows of buildings where foodstuffs are prepared and where flies endeavor to enter through the windows or escape after having gained entrance through other passageways. All openings not provided with traps should be closely screened, and on large buildings traps may be installed in every third window. [Illustration: Fig. 7.--Hodge type window trap. At left, trap with end removed to show construction; at right, cross section of trap placed in a window. _A_, End of trap. _B_, Upper side of folds in screen. _C_, Lower side of folds in screen. _D_, Portion of end of trap sawed out and returned after attaching screen. _E_, Holes along apex of folds. _F_, Door for removing dead flies. _G_, Window sill. _H_, Upper window sash. _I_, Inside entrance for flies. _O_, Outside entrances.] This trap is essentially a screen box closely fitted to the frame of a window (see fig. 7). The thickness of the box at _A_ should be about 12 inches. Instead of the screen running straight down over the box on either side it is folded inward nearly to the center of the frame in =V=-shaped folds running longitudinally across the window. One, two, or even more folds may be made in the screen on either side. The upper side of the fold _B_ should extend toward the center almost at right angles 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 downward 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 window 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.=[5] [5] _Chrysomyia macellaria_ Fab.