Part 3

=MANURE-BOX TRAPS.=

Manure pits or boxes are desirable for the temporary storage of manure, especially in towns and cities. These have been widely advocated, but the difficulty has been that manure often becomes infested before it is put into them, and flies frequently breed out before the boxes are emptied and often escape through the cracks. To obviate these difficulties a manure box or pit, with a modified tent trap or cone trap attached, is desirable. Mr. Arthur Swaim, of Florida, has devised a form of manure trap consisting of a series of screen tents with exit holes along the ridges of these, over which is a screen box. The latter retains the flies as they pass through the holes in the tents. The entire trap is removable.

In order to retain the fertilizing value of manure to the greatest extent it is advisable to exclude the air from it as much as possible and to protect it from the leaching action of rains. This being the case, there is really no necessity to cover a large portion of the top of the box with a trap, but merely to have holes large enough to attract flies to the light, and cover these holes with ordinary conical traps, with the legs cut off, so the bottom of the trap will fit closely to the box. The same arrangement can be made where manure is kept in a pit. In large bins two or more holes covered with traps should be provided for the escape of the flies.

Manure boxes should be used by all stock owners in towns and cities, and they are also adaptable to farms. The size of the manure bin should be governed by the individual needs, but for use on the farm it is desirable to make it large enough to hold all of the manure produced during the busiest season of the year. A box 14 feet long, 10 feet wide, and 4 feet deep will hold the manure produced by two horses during about five months. About 2 cubic feet of box space should be allowed for each horse per day. The bin should be made of concrete or heavy plank. When the latter is used the cracks should be battened to prevent the escape of flies. The bin may have a floor or it may be set in the ground several inches and the dirt closely banked around the outside. For the admission of the manure a good-sized door should be provided in either end of a large bin. A portion of the top should be made easily removable for convenience in emptying the box, or one entire end of the box may be hinged. On account of the danger of the door being left open through carelessness, it is advisable to arrange a lift door which can be opened by placing the foot on a treadle as the manure is shoveled in. The door should be heavy enough to close automatically when the treadle is released. A manure bin with flytrap attached is shown in figure 6.

Attention is directed to a maggot trap devised by Mr. R. H. Hutchison, as described in Farmers' Bulletin 851 of the Department of Agriculture. Where large quantities of manure are produced on a farm this method of storing the manure on a platform and trapping the maggots which breed out may be more convenient than the manure bin.

=WINDOW TRAPS.=

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.

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.=

Chrysomyia macellaria Fab.

Recent efforts to reduce the loss to the live-stock industry of the Southwest resulting from the ravages of the screw-worm have directed attention to the employment of flytraps in this work.

Mention has been made of the importance of preventing the breeding of flies as a prerequisite to effective control. This is equally true of the screw-worm and other blowflies, which attack animals, and of the house fly. In the case of these blowflies main dependence must be placed on the complete and prompt burning of all carcasses and animal refuse.

Experiments conducted in the range sections of Texas indicate that traps properly baited and set are of material aid in preventing screw-worm injury to live stock. It is advised that at least one trap be maintained on each section of land. These should be located preferably near watering places and where cattle congregate, especially in the so-called "hospital traps," where the screw-worm-infested animals are kept for treatment.

The conical-type traps as described are advised. The traps should be set on a board platform about 2 feet square, securely fastened to a tree or on a post where the trap and bait will be the least disturbed by stock or wild animals.

During the latter half of one season over 100 gallons of flies, the vast majority of which were screw-worm flies, were captured in about 25 traps operated on a ranch in west Texas.

The question of the baits best adapted for this species and other points in regard to the operation of the traps are briefly discussed under subsequent headings.

=BAITS FOR TRAPS.=

The problem of selecting the best bait for flies is an important one. In choosing a bait it should be remembered that it is largely the fermentation which renders the material attractive, and that baits are most attractive during their most active period of fermentation. As has been indicated, the kind of bait used should be governed by the species of flies the destruction of which is desired. This is most often the house fly.

Experiments conducted indicate that a mixture of cheap cane molasses ("black-strap") and water is among the most economical and effective baits for the house fly. One part of molasses is mixed with three parts of water. The attractiveness becomes marked on the second or third day.

Sugar-beet or "stock molasses," which is very cheap, especially in regions where produced, when mixed in the foregoing proportions, is fairly attractive.

On dairy farms, probably milk is the next choice as a bait to cane-molasses solution, considering its convenience. The curd from milk, with about one-half pound of brown sugar added to each pound and water to make it thoroughly moist, is a very good bait and continues to be attractive for 10 days or more if kept moist. A mash of bran made quite thin with a mixture of equal parts of water and milk and with a few tablespoonfuls of brown sugar and cornstarch and a yeast cake added makes an attractive and lasting bait. During hot weather stirring the old bait or adding fresh is a daily necessity if best results are to be secured.

Sirup made by dissolving 1 part of ordinary brown sugar in 4 parts of water and allowing the mixture to stand a day or two to induce fermentation is almost equal to the molasses and water as a fly bait. If it is desirable to use the sirup immediately after making it, a small amount of vinegar should be added. Honeybees are sometimes caught in large numbers at this bait. When this happens some of the other baits recommended should be used.

With the baits before mentioned comparatively few blowflies will be caught. For use about slaughterhouses, butcher shops, and other places where blowflies are troublesome, it has been determined that the mucous membranes which form the lining of the intestines of cattle or hogs are without equal as a bait. This material, which is commonly spoken of as "gut slime," can be obtained from packing houses where sausage casings are prepared. The offensive odor of this bait renders its use undesirable very near habitations or materials intended for human consumption.

For use under range conditions experiments are underway with dried gut slime. This material is giving satisfaction as a screw-worm fly attractant and is easily carried, being in a highly concentrated form. The flaky material is placed in the bait pans and water added at the rate of 1 part slime to 10 or 20 parts water, after which the mixture is thoroughly stirred.

Another packing-house product known as blood tankage is a good fly bait when used with molasses and water. This combination results in the capture of a large percentage of house flies. Where these materials are not obtainable fairly good catches will result from the use of fish scraps or meat scraps. With any of these baits the catches will be found not to be entirely meat-infesting flies, as actual counts have shown that the percentage of house flies in traps over such baits ranges from 45 to 75.

Overripe or fermenting fruit, such as watermelon rinds or crushed bananas, placed in the bait pans sometimes gives satisfactory results. A combination of overripe bananas with milk is much more attractive than either one used separately. A considerable number of blowflies as well as house flies are attracted to such baits.

=BAIT CONTAINERS.=