Meat and Egg Producing Animals as Bio-Control Agents

In a paper that will be published in The Journal of Econonic Entomology, B. D. Glofcheskie and G. A. Surgeoner of the University of Guelph, describe the use of Muscovy ducks in an integrated program for the control of house flies (Musca domestica) on farms in Canada. This represents a biological approach that has probably received too little attention.

The ducks go after the adult flies. Chickens may use a different tactic – going for the fly larvae, or possibly for both the larvae and adult flies. In a study in 1972 at the University of Wisconsin Electric Research Farm, Dr. W. L. Gojmerac (UW extension entomologist) observed the activity of leghorn cockerels that were fenced in on a free-drop cattle manure stack and on a blower stack (Project 1763 Final Report: Manure Handling as Related to Fly Control [mimeograph]). The fly population (Musca domestica) on the farm had been very high the preceding summer. The chickens appeared to aggressively work the stacks, scratching for maggots and possibly also for corn that had passed through the cattle (the cattle were on a corn silage and ground ear corn diet). The chickens were given a small amount of additional feed once daily, in the evening.

Numerous inspections indicated that the chickens, numbering 300 initially and about 225 later, kept the free-drop stack

essentially free of maggots throughout the summer. In midsummer 75 of the chickens were moved to the blower stack, where treatment with the insecticide dimethoate was not providing satisfactory fly control. Maggots, although reduced in number, continued to be found on occasion in this stack, suggesting that the chicken population was too low. The late start may also have contributed.

Most research aimed at using fly larvae or pupae as a high protein source for poultry has envisioned recycling manure by rearing larvae under controlled conditions. The above results on ducks and chickens suggest that more research on management schemes involving the controlled use of these animals as predators is warranted.

Also, might this be a viable approach to “mining” some of the other kinds of agricultural wastes that occur in the tropics? In recent correspondence, Professor J.J. Castro mentions for example that coffee pulp and cacao husks are among the waste accumulations in Colombia that favor the growth of numerous insects.

Just as this issue of the Newsletter had been finalized for the printer, Dr. Gordon Surgeoner called attention to a paper by Rodriguez and Riehl (1962) describing the control of flies by the use of cockerels on commercial poultry ranches in southern California. The investigators reported reductions to zero, in some cases, of fly larvae and pupae (M. domestica) a) in chicken manure under cages with a raised wire mesh floor when cockerel chicks were released on the ground. Control was maintained with ratios of 20 to 100 hens in cages per one cockerel on the ground. The authors describe management practices favorable to successful fly control by the chicks.

in the laboratory, baby chicks only 1-2 days old were found to peck instinctively at larvae and pupae although they were unable to pick them up. At 3 days of age the chicks ate 100 larvae or pupae per chick per day and by 15 weeks of age were averaging 8,000 or more per day. The consumption of flies (200 grams/day) was higher than the consumption of mash or grain on a free-choice basis. Under ranch conditions, feed was supplied in the evening for the first few days but not thereafter unless fly breeding was completely eliminated.

At a rabbitry with 175 rabbits, control of fly larvae and pupae was obtained with one cockerel per five rabbits.

Rodriguez, J. L. and L. A. Riehl. 1962. Control of flies in manure of chickens and rabbits by cockerels in southern California. J. Econ. Entomol. 55:473-477.