182 



in the island. The Hfe-history and habits of this pest as occurring 

 in the United States are described. If the fly should become 

 estabhshed in the Ha^'aiian Islands, it is thought that the life-cycle 

 might be shortened and that development might be continuous as 

 in the case of the house-fly [Mttsca domestica] and horn-fly [Lyperosia] . 

 Warbles found on imported cattle should be destroyed either by 

 removing them by pressure or by rubbing into the afiected parts of 

 the hide a little kerosene or mercurial ointment. 



Babcock (O. G.). U.S. Bur. Ent. & Bennett (D. H.). The Screw 

 Worm and the Wool Maggot. — Texas Agric. Expt. Sta., College 

 Station, Circ. 27, April 1921, 15 pp., 7 figs. [Received 31st 

 August 1921.] 



Cattle in Texas suffer considerably from the attacks of Cochliomyia 

 (Chrysomvia) macellaria, F. (screw-worm fly), which is said to cause 

 an annual loss of at least ;/;800,000 in the United States alone. The 

 life-history and habits of the fly are described [R.A.E.,V,, vi, 148-150]. 

 The method of dispersion is by flight, marked flies having been known 

 to travel at least 15 miles. Several days of warm weather, with a 

 maximum temperature of about 80° F. are necessary before oviposition 

 takes place, this seldom occurring before May. Warm, showery 

 weather favours breeding, which ceases about the middle of December. 



Clean sanitation and the immediate destruction of ah carcasses 

 is one of the best measures for preventing the increase of the fly. 

 A carcass should be completely burnt by placing it on a pile of wood, 

 or by digging a trench about a foot deep, filling it with wood and rolHng 

 the animal on to the pile. It is questionable whether vultures and 

 other scavengers are of much use in this connection ; in any case 

 they do not destroj' carcasses sufficiently to prevent breeding of the 

 flies. 



Various methods of poisoning the flies have been tried. Carcasses 

 have been partly skinned, and the exposed flesh slashed and treated 

 with a solution of 1 lb. white arsenic in 5 U.S. gals, of boiling water. 

 A more successful method is to kill a goat or sheep, skin and partly 

 gut it and suspend it from a tree, with the head, neck and shoulders 

 in a tub containing such a poison as 4 liquid oz. sodium arsenite or 

 1 or U U.S. gals, of arsenical dip mixed with 7 to 10 U.S. gals, of 

 water. " Both screw-worm flies and blow-flies are attracted to the 

 bait, and most of them sip some of the poison before leaving. These 

 baits, however, do not remain attractive for more than a week or 

 ten days. 



A trap that has given much success consists of a cylinder of wire 

 gauze 24 in. high and 18 in. in diameter, with a screened top and, 

 at the bottom, a cone 22 in. high, with a 1-| in. opening at the top. 

 This trap is set on a platform and placed in a tree, somewhere along a 

 stream or water-hole, where the flies seem to congregate, at about 

 4 or 5 ft. above ground and in the shade. The bait may be a rabbit 

 cut open and placed in the bait-pan, meat of any kind, entrails of 

 animals, or, best of all, a large rattlesnake. Dried gut slime, using 

 about 6 oz. to 2 quarts of water, seems a promising bait. Trapping 

 and poisoning alone, however, are not dependable methods without 

 systematic destruction of carcasses. 



The prevention of wounds or raw places on animals is of the greatest 

 importance, and when they occur they should be protected from 

 infestation. "Wlien maggots are already present, they should first 



