Ohio ranks second in the nation behind California in caged-layer egg production.
One of the largest management problems facing the poultry producer of today is fly control. The shift from many small farm flocks to fewer large poultry operations has greatly increased fly problems by providing concentrated breeding areas in large volumes of waste that cannot be removed frequently. As urbanization and rural nonfarm residence increase, poultry producers are faced with increasing pressures to reduce fly populations to low levels. Fly populations (manure breeding flies) may cause a public health nuisance, resulting in poor community relations and threats of litigation. A dedicated effort is necessary to achieve an acceptable level of fly control.
There are several kinds of flies common in and around caged layer houses in Ohio. Probably the most common flies are the house fly and the little house fly. About 95 percent of problems involve the house fly. Both of these flies are capable of movement up to 20 miles from the site of development, but normally move no more than a mile or two from the initial source.
House flies, Musca domestica L., about 1/4 inch long, breed in moist, decaying plant material, including refuse, spilled grains and spilled feed, and in all kinds of manure. Consequently, house flies are more likely to be a problem around poultry houses where sanitation is poor. These flies prefer sunlight and are very active, crawling over filth, people and food products. This fly is the most important species from the standpoint of spreading human and poultry diseases in addition to flyspecking of eggs. House flies are the intermediate host for the common tapeworm in chickens. Flies carry millions of bacteria.
The little house fly, Fannia canicularis (L.), about 3/16 inch long, is somewhat smaller than the house fly. This fly prefers a less moist medium than the house fly in which to breed and reproduce. Poultry manure is preferred over most other media. This fly prefers shade and cooler temperatures and is often seen circling aimlessly beneath hanging objects in the poultry house, egg room and feed room. It is less likely to crawl about on people and food. However, it does cause persons living near poultry establishments to complain about fly problems. The little house fly may hover in large numbers in nearby garages, breezeways and homes because it prefers shade.
The black garbage fly, Ophyra aenescens (Wiedemann), is slightly smaller than the house fly, shiny bronze-black colored, wings held straight back, tends to stay on the food source at night rather than resting on the ceiling or outdoor vegetation, as does the house fly. The female fly seems to have limited flight activity, but has been found about five miles from its breeding area. Although black garbage fly larvae have been known to exterminate house fly populations, they should not be considered entirely beneficial due to the buildup of large numbers on the farm and the ability to disperse as adults in nearby communities. All stages are found throughout the year under suitable conditions with rather good tolerance to cold weather. The life cycle is similar to the house fly.
Blow flies, sometimes known as green or blue bottle flies, are slightly larger than house flies and sometimes occur in poultry houses. They prefer to breed and reproduce in decaying animal and bird carcasses, dog manure, broken eggs and wet garbage. Generally, a good sanitation program will hold these flies in check.
Other flies found on the poultry establishment include soldier flies, small dung flies, fruit flies and rattailed maggots.
All flies pass through four life stages: egg, larva, pupa and adult. Adult flies deposit small, white oval eggs on the breeding media, and creamy, white larvae (maggots) develop in this moist (wet) material. Mature maggots crawl out of this material and move to a drier place for pupation. The brown seedlike puparia finally yield adult flies. Development from egg to adult fly may take place as quickly as seven to ten days under ideal conditions. Adult house flies live about three to four weeks with females laying between two to twenty batches of 75 to 200 eggs at three to four day intervals. A pair of flies beginning operation in April, if all were to live, would result in 191,010,000,000,000,000,000 (191 quintillion, 10 quadrillion) flies by August. Allowing 1/8 cubic inch to a fly, this number would cover the earth 47 feet deep. Of course, this does not happen due to beneficial predators and parasites. Flies in the poultry house can be present the year around if there are warm temperatures and no true diapause.