With the advent of pesticides, the use of the trap stopped and only recently has it been brought back as a possible fly management tool for grazing cattle. The principle of the trap is simple. Cattle are forced to walk through a narrow chute that is lined with fly trap boxes. The dark roof of the trap, canvas strips in the chute and on the end of the chute causes the flies to leave the cattle as they walk through the trap to and from water. The flies land on the sides of the trap and enter one of the trapping boxes from which they cannot escape.
Flies soon die in the trap sides and fall to the bottom of the trapping boxes.
This study was conducted to compare the effec tiveness of the trap with an eartag-treated group and an untreated herd. Two groups of cattle were tagged with Patriot Insecticide Ear Tags at the same date. The data from the trial are presented in Table 1 and Table 2 for Horn Fly Control and Face Fly Control, respectively. Face fly control is difficult to evaluate because the time of application of the eartags and installation of the trap was near the end of the face fly season. It appears that some control was gained with the ear tags but the trap and control populations decreased also, although not to the same degree as for the tagged animal group.