Management of manure-breeding flies

A variety of methods are available for use in integrated pest management (IPM) programs for filth flies.  Because 1000 flies can be produced from as little as 500 cc of manure, sanitation or manure management is the first line of defense.  Frequent manure cleanouts are helpful, as is good ventilation and correction of water leaks and drainage problems that lead to wet manure hot spots.  A variety of naturally occurring biocontrol agents are favored by preventing wet manure.  These include beetle and mite predators of fly immatures and parasitic wasps (parasitoids) that attack the fly in the pupal stage.  Some of these agents are available for purchase and release, and their use can be helpful when combined with sanitation and avoidance of broadcast application of chemical insecticides.  Adult flies are also susceptible to diseases that include fungal and viral agents.  One of the fungal pathogens, Beauveria bassiana, is available as a commercial product in both bait and spray forms.  The viral pathogen SGHV has the attractive feature of sterilizing adult flies but development of the virus into a product for field use has proven elusive.  A variety of traps are also available for adult flies.  These include electrocuting black light traps and a variety of liquid baited models such as the Terminator and Fly Magnet.  The house fly is notorious for ability to develop resistance to chemical insecticides very rapidly.  Any product that is used on continuous basis often eventually fails because of resistance.  This is especially true for residual premise treatments and the use of feed-through products which put constant pressure on the fly population.  Judicious use of insecticidal baits is an important component of fly control programs, but overreliance of individual products also leads to resistance issues.  Some insect growth regulators have promise for fly control as well.