Fly Parasites- What Are They and How Do They Work

Fly Parasites are commonly referred to as Fly Predators or Fly Parasitoids and are one of nature's methods of fly control. Fly Parasites are very tiny wasps (size of a fruit fly) that are naturally occurring in nature, mainly nocturnal, and do not pose any harmful influence on humans, livestock or pets. While other organisms attack adult flies (e.g. birds, spiders, etc) the Fly Parasites target the developing flies. Under circumstances normally observed in nature, these natural controls keep a balance in the fly population. It is when we artificially increase the concentration of animals that we provide an ideal breeding environment for fly reproduction and the natural controls cannot keep up to the explosion in the fly population.

Fly Parasites have a unique and highly effective method to locate their prey. The adult females fly about searching for a fly pupa and when they sense a fly pupa they will burrow up to six inches (15cm) into the manure or compost in order to reach the prey. They then deposit their eggs into the fly pupae and the young Fly Parasites will consume the fly pupae as nourishment while developing into adult Fly Parasites. Each female will lay between 50 to 150 eggs depending on the species. These adults emerge fully-grown and ready to search out more fly pupae and start the reproductive cycle again. Normally, this cycle takes 18-21 days depending on the species of Fly Parasite and temperature. The adult Fly Parasites also consume some of the fly pupae as a food source thus providing a secondary method of reducing the potential fly population.

Life Cycle of Flies and Fly Parasites

Life Cycle of Fly Parasites

(Courtesy of

Fly Parasites provide an environmentally safe, economically effective and long term fly control method by interrupting the reproductive cycle of the pest fly. Studies in stables, and poultry and dairy operations have reported stable fly reductions of over 90% using Fly Parasites and effective suppression of fly populations within 30 days.


Why Are Fly Parasites So Effective?

Reliance on the use of insecticides alone for fly control seldom provides a satisfactory solution. In the past chemical sprays or fogs have been used as a common method to control fly populations. These chemicals provide a short term relief asthey kill the adult flies, but after a couple of days the problem has returned. The chemicals only attack the adult flies and as only 15-20% of the fly population at any one time is adults, the chemicals are only targeting a very small portion of the fly population. The remaining 80-85% of the fly population is under the manure or compost in the developing stages and is not killed by the chemicals. In fact many of the developing flies ingest the chemicals on the surface of the manure and will form a resistance to the chemicals. The net result is that farmers have to apply stronger doses of the chemicals and have less success in knocking down the population. Furthermore, there is increasing scientific research on the adverse effects of these pesticides on humans and the environment. 

This is not to discount the importance of controlling the adult flies, but we prefer the use of fly baits, fly traps and fly strips, as they do not have adverse effects and are very localized.

Fly Parasites (compared to chemical sprays) on the other hand do not have any adverse influences on humans or the environment and the key is that they target the developing flies at the pupal stage. These developing stages comprise the remaining 85% of the fly population and the developing flies are killed before they become adults and do not have a chance to lay any eggs.

Please contact us for a NO OBLIGATION discussion on a customized fly control program (1-888-668-7264). We are not after a fast sell, but rather we hope to have a long-term satisfied customer. Our business has grown across Canada virtually by word of mouth and we welcome all enquires. Our commitment to you is to create the BEST, MOST ECONOMICAL AND LONG-TERM BIOLOGICAL FLY CONTROL PROGRAM

Toll Free: 1-888-668-7264             Phone: 250-468-7264            Email:            196 Westwood Road, Nanaimo BC, V9R 6S3 Canada