Transcriber Note Text emphasis denoted as _Italics_ and =Bold=. Whole and fractional parts of numbers as 123-4/5. =FLYTRAPS AND THEIR OPERATION= F. C. BISHOPP Entomologist, Investigations of Insects Affecting the Health of Animals [Illustration] FARMERS' BULLETIN 734 UNITED STATES DEPARTMENT OF AGRICULTURE Contribution from the Bureau of Entomology L. O. HOWARD, Chief Washington, D. C. Issued June 10, 1916; second revision, March, 1921. Show this bulletin to a neighbor. Additional copies may be obtained free from the Division of Publications, United States Department of Agriculture WASHINGTON : GOVERNMENT PRINTING OFFICE : 1921 RESULTS obtained in experiments with the use of chemicals against fly larvæ in manure are presented in Bulletins Nos. 118, 245, and 408 of the Department of Agriculture. The biology of the house fly and the various methods of control are discussed in Farmers' Bulletin 851. This bulletin is intended to give directions for the use of a supplementary means of controlling flies. It is adapted to all parts of the United States. =FLYTRAPS AND THEIR OPERATION.= =CONTENTS.= Page. Uses and limitations of flytraps 3 Kinds of flies caught 3 Types of traps 4 Trapping the screw-worm fly 13 Baits for traps 13 Bait containers 15 Care and location of traps 15 Sticky fly papers 16 Poisoned baits 16 Caution 16 =USES AND LIMITATIONS OF FLYTRAPS.= FLYTRAPS have a distinct place in the control of the house fly and other noxious fly species. There is a general tendency, however, for those engaged in combating flies to put too much dependence on the flytrap as a method of abating the nuisance. It should be borne in mind that flytrapping is only supplementary to other methods of control, most notable of which is the prevention of breeding either by completely disposing of breeding places or by treating the breeding material with chemicals. It may be said that there are two main ways in which flytraps are valuable: (1) By catching flies which come to clean premises from other places which are insanitary and (2) by capturing those flies which invariably escape in greater or less numbers the other means of destruction which may be practiced. Furthermore, the number of flies caught in traps serves as an index of the effectiveness of campaigns against breeding places.