In addition to arthropods, there are several species of naturally occurring entomopathogenic fungi that are associated with flies.

These micro-organisms can be found in both intensive and extensive farming systems, and unlike many of the arthropods, grow best in moist area.

Some species have a broad spectrum of activity (e.g. Beauveria bassiana which can infect many insect species). Other species of fungi are more selective (e.g. Metarhizium anisopliae and Paecilomyces fumosoroseus, which are more effective against the face fly and the horn fly).

In addition, some strains of fungi are more active than others.

Most species are only active against adult flies. However, some species also have limited activity against larvae.

Some of the most studied fungi for fly control in livestock systems are Bavaria bassiana and Entomophthora muscae.

 

 

Fly Infection By Fungi

Fungal infection of flies occurs primarily through the cuticle rather than through the digestive tract.

The fungi penetrate the cuticle and proliferate in the haemolymph. The fly then dies quite rapidly.

The fungus emerges through the cuticle, forming a mycelium which contains the next generation of spores.

These spores are then spread to other flies by wind, or by direct contact between dead and living flies.

It takes five to seven days for a flie to die after its cuticle has been penetrated by fungus.

To be active, the spores need humid conditions. Therefore, even though many fungi are able to kill flies, the natural fungal population level is rarely high enough to have a significant impact on fly populations.

Fungi form stages resistant to dry conditions, in order to survive throughout the year. As a consequence, there is a continuous level of resting spores in the environment.

 

 

Application Of Fungi

Research on the use of fungi to control flies has focused on increasing the number of infective spores during fly season, through the use of baits and "paints".

Commercial preparations of fungi, that can be applied using conventional spray equipment and baits, have been successfully developed for the control of cockroaches, grasshoppers (for field crops) and whiteflies, aphids and mites (in greenhouses).

However, formulations for fly control in livestock and poultry production are only available on a limited basis.