THE HOUSE FLY. 13 



the barrel hoops, barrel head, lath, and strips can be obtained with- 

 out expense. 



"In constructing the trap two of the hoops are bent in a circle (18 

 inches in diameter on the inside), and nailed together, the ends being 

 trimmed to give a close fit. These form the bottom of the frame 

 (A), and the other two, prepared in a similar way, the top (B). The 

 top (C) of the trap is made of an ordinary barrel head with the bevel 

 edge sawed off sufficiently to cause the head to fit closely in the 

 hoops and allow secure nailing. A square, 10 inches on the side, is 

 cut out of the center of the top to form a door. The portions of the 

 jtop (barrel head) are held together by inch strips (D) placed around 

 the opening one-half inch from the edge to form a jamb for the door. 

 The door consists of a narrow frame (E) covered with screen (F) well 

 fitted to the trap and held in place (not hinged) by buttons (G)'. The 

 top is then nailed in the upper hoops and the sides (H) formed by 

 closely tacking screen wire on the outside of the hoops. Four laths 

 (7) (or light strips) are nailed to the hoops on the outside of the trap 

 to act as supports between the hoops, and the ends are allowed to 

 project 1 inch at the bottom to form legs (J). The cone (K) is cut 

 from the screen and either sewed with fine wire or soldered where the 

 edges meet at L. The apex of the cone is then cut off to give an 

 aperture ( M) 1 inch in diameter. It is then inserted in the trap and 

 closely tacked to the hoop around the base." l 



The effectiveness of the traps will depend on the selection of a good 

 bait. For attracting house flies beer is probably the best. It loses 

 much of its attractiveness after the first stages of fermentation are 

 over, and for this reason it should be renewed every day or two. Milk 

 is also a good bait. Overripe or fermenting bananas crushed and 

 placed in the bait pans give good results. A combination of bananas 

 and milk is more attractive than either used separately. A mixture 

 of 3 parts water and 1 part cheap molasses is very attractive after it 

 has been allowed to ferment for a day or two. A mixture of equal 

 parts brown sugar and cheese (or curd of sour milk), thoroughly 

 moistened, gives good results after it has been allowed to stand for 

 three or four days. For catching blowflies and other meat-infesting 

 flies the best bait is the mucous membrane from the lining of the in- 

 testines of hogs. Ordinary fish or meat scraps may be used. 



PREVENTIVE MEASURES. 



Fly papers, poisons, and traps are at best only temporary expedi- 

 ents. The most logical method of abating the fly nuisance is the 

 elimination or treatment of all breeding places. It would appear 

 from what is known of the life history and habits of the common house 



i Bishopp, F. C. Flytraps and their operation. U.. Dept. Agr. Farmers' Bui. 734, p. 3-5. 1916. 



