Simply sprinkle them out of the bag onto the manure or staple to posts or rafters near areas where fly breeding is a problem. Costs Parasite release costs are usually offset by reduction in insecticide treatments. In research trials, dairy farmers using fly parasites have made as much as 80 percent fewer insecticide treatments with 50 percent lower fly populations than on conventional insecticide control farms. There is still much to learn on using fly parasites most effectively in fly management programs. Prices vary from company to company on fly parasite purchase prices.
Approximate costs are as follows.
Consequently, it is best to release small amounts of fly parasites throughout the fly season rather than just one large release. Make weekly releases of 250 wasps per animal from mid to late May to August or September. However, each farm is different. Commercial farms that generate large quantities of manure should import fresh parasites weekly. For small farms, choose a biweekly, triweekly or monthly schedule.