58 CIRCULAR 9 7 7, U. S. DEPARTMENT OF AGRICULTURE 



taming 3 to 10 percent of blackstrap molasses, sugar, or corn syrup. 

 TEPP hydrolyzes rapidly in water and must be used fresh, but the 

 other compounds will remain effective in water for several weeks or 

 more. In these tests the baits were sprinkled on the floor of dairy 

 barns at various locations where the flies congregated. An ordinary 

 garden sprinkling can having about half the holes closed with solder 

 to reduce the flow was used. Treatments made daily 5 days each 

 week gave excellent control. 



Malathion, Diazinon, Bayer L 13/59, and Clilorthion mixed with 

 granulated sugar make highly effective dry baits. One percent of 

 these insecticides is recommended, but good results have been obtained 

 with concentrations as low as 0.25 percent. Wettable powders arc 

 preferred in making dry baits, but emulsifiable concentrates or the 

 technical insecticide may be employed. A small amount of black 

 or yellow food coloring should be added to dry sugar baits in order 

 to minimize the possibility of their being mistaken for and used as 

 regular sugar. 



The dry bait is distributed from a shaker-top can or fruit jar with 

 holes punched in the lid. Dry bait should be sprinkled thinly in 

 strips on the floor or other places where flies congregate but where it 

 will not contaminate animal feed, human food, or utensils. Usually 

 about 1 ounce is needed for each 500 to 1,000 square feet, depending 

 on the number of flies. Daily applications may be necessary to 

 control flies under certain conditions, but after 2 or 3 weeks breeding- 

 may be reduced so that satisfactory control can be maintained with 

 2 to 4 applications per week. 



Dry sugar bait is most effective on dry surfaces that are not very 

 porous. On loose material such as straw the bait may fall beyond 

 the reach of the flies, and on damp surfaces the sugar usually dissolves 

 before the flies have a chance to eat it. In such cases the dry bait 

 should be applied on feed sacks, sections of heavy paper, wood, or tin 

 placed in locations where flies congregate. 



An alternate bait for use on damp surfaces, especially outdoors, 

 may be prepared with coarsely ground cornmeal. The meal is first 

 coated with vegetable oil, 2 tablespoonfuls to 1 pound, and then are 

 added 6 tablespoonfuls of a 25-percent malathion or Diazinon wettable 

 powder and 4 tablespoonfuls of powdered sugar. If desired, 3 table- 

 spoonfuls of lampblack may be added for coloring. The material 

 should be thoroughly mixed with a paddle or mechanical stirrer. 

 Cornmeal bait is applied in the same manner as dry sugar bait. 



In view of the high toxicity of organic phosphorus insecticides to man, 

 great care must be used in handling the concentrates. Because of the 

 low concentrations in the bait and the method of application, they are 

 not regarded as particularly hazardous if reasonable care is taken to 

 avoid spillage on skin or clothing. 



LARVICIDES 



For military purposes fly larvicides are employed chiefly for con- 

 trol of larvae in latrines, garbage clumps, and other accumulations of 

 waste. In combat areas the control of fly breeding in dead bodies is 

 also imperative at times. Paradichlorobenzene, sodium arsenite, 

 DDT, dieldrin, BHC, or lindane may be used as larvicides. 



