Stable Fly Management
The Shire of Gingin has been, and continues to be, affected by large populations of Stable Fly (Stomoxys calcitrans L.), particularly in the warmer weather. As a result the Shire works closely with the Department of Primary Industries and Regional Development (DPIRD) with a collective view to combating the problem.
Stable Fly is a serious pest to livestock owing to its painful bite when it draws blood during feeding.
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| An adult Stable Fly |
Stable Fly feeding on a human |
Stable Fly (left) vs Common House Fly (right) |
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What is Stable Fly?
“Biting Fly” or “Stable Fly” (Stomoxys calcitrans L.) is slightly smaller than the Common House Fly and slightly bigger than a Bush Fly, but differs in having a checkerboard of dark spots on the back of the abdomen. The main distinguishing feature however, is its prominent black proboscis that is used to pierce the skin and draw blood.
Stable Flies are persistent biters, feeding on animals several times a day, preferring to bite cattle and horses but will also attack humans, dogs, pigs, new-born lambs, pet kangaroos and emus. The bite from this fly can be painful and therefore has the potential to cause considerable distress.
What causes Stable Fly to breed?
There are five major elements contributing to Stable Fly breeding:
- Rotting vegetable matter, including vegetable production waste, hay, animal bedding and animal feed.
- Mammalian blood (preference is cattle and horse, but human, dog, kangaroo and sheep blood is also targeted).
- Sandy, free-draining soils ie, the Swan Coastal Plain.
- Moisture (rainfall and irrigation).
- Warm temperatures (spring to autumn is ideal – Stable Flies are resilient to hot January days greater than 35oC).
Removing any one of these elements will limit the ability for Stable Flies to exist.
What is the impact of Stable Flies on livestock?
Stable Fly is a very serious pest - they cause particularly serious animal welfare issues within the grazing and equine industries. Their harmful effects can also result in significant financial consequences to these industries.
Animals will try to avoid the fly by stamping their feet, tail switching, throwing their heads down toward their front legs, and kicking sand up onto their legs and body. When Stable Flies are present in large numbers (more than 20-30 per animal), cattle will often bunch together in an effort to get to the centre of the group to avoid the fly, or they may stand in open water to avoid being bitten.
This continual agitation can lead to loss of weight and condition from continual movement and allergic reactions on their skin from the bites. It can also reduce the animal’s normal grazing time as they resort to feeding at night when the fly is not active. Bunching together by cattle is particularly hazardous in summer where animals can be at risk of heat stroke.
Stable fly numbers can be monitored by counting the flies on all four legs of about 10 animals. When the average number is more than 25 flies per animal (treatment threshold), action is needed. At more than 25 flies per animal, measurable reductions in weight gain and condition occur and numbers above 50 flies per animal can reduce weight gain by 25% and milk production by 40–60%.
Who is responsible for managing Stable Fly in the Shire of Gingin?
The Department of Primary Industries and Regional Development (DPIRD) is the key agency responsible for the administration of the Biosecurity and Agriculture Management Act 2007 (“BAM Act”) and the Stable Fly Management Plan (“SFMP”).
A Shared Responsibility with Shires Agreement includes DPIRD working with the Shire of Gingin to deliver the following actions:
- Monitor and react to public interactions through the My Pest Guide app, Pest and Disease Information Services (PaDIS), and other electronic communications.
- Assist in the response to these interactions as appropriate.
- Keep a central database of those interactions.
- Provide training to Shire inspectors acting under the BAM Act.
- Manage stakeholder relations in consultation with the Shires.
- Manage education and communication with the public and industry in association with the Shires.
The Shire of Gingin is responsible for on-ground response to reports, inspections, evidence gathering, and warnings of non-compliance.
What can I do to minimise Stable Fly breeding?
While there are registered pesticides that can be used to control both larvae (maggots) and adult flies, the main objective is to eliminate breeding sites. You can help by:
- Not feeding vegetable waste to livestock unless in a trough or box to prevent mixing with soil.
- Preventing the build-up of hay residues or split grain feed.
- Keeping animal enclosures clean on a daily basis.
- Collecting and disposing of manures, including soiled straw or litter bedding from enclosures such as horse stables and poultry runs, both commercial and domestic.
In dealing with livestock feed:
- Keep waste in a fly-proof bin/container or in accordance with the appropriate Codes of Practice and BAM Act.
Association with raw poultry manure
DPIRD has discovered an association between the use of poultry manure and rotting vegetable matter in relation to the breeding of Stable Fly. Therefore commercially derived untreated poultry manure must not be stored or used on land for agricultural activity or transported within the Shire of Gingin (in accordance with the BAM Act).
Additionally, farmers feeding bulk vegetable waste to their stock may also be contributing to Stable Fly breeding, particularly if the vegetable waste is not spread thinly in paddocks.
The Shire of Gingin requests that the public be vigilant regarding Stable Fly infestations and report any fly breeding or excessive numbers to DPIRD on 1800 675 888 or download DPIRD's MyPestGuide Reporter app.
Please see the Stable Fly Action Group website for more information.
Where can I find out more about Stable Flies?
Shire Enquiries
Please contact the Shire of Gingin's Stable Fly Officer for further information on (08) 9575 5100.