BUSINESS stable fly
Stamp out
STABLE FLY
Poorly managed vegetable waste on farms and market gardens can become major breeding sites for stable fly. More than just a nuisance, stable fly deliver painful bites that cause stress to livestock, pets, and people, with impacts felt both onfarm and across surrounding communities. Infestations can also result in significant economic losses for livestock producers.
Words Chantelle Lustri
THE Department of Primary Industries and Regional Development Director of Invasive Species, Environment and Biosecurity, Ron Shepherd, said the stable fly breeds in rotting vegetable waste, reject produce, and moist plant residues.
“Good management of organic waste including drying waste plant material, turning-off irrigation immediately after harvest, and monitoring sites regularly for pupae and larvae is far more effective than trying to eliminate the adult flies after they hatch from their pupae,” he said.
In Western Australia, some horticulture-intensive regions fall into one of 14 local government areas where stable fly is a declared pest and must be controlled.*
“Leaving plant waste unmanaged during prolonged harvesting or after harvest, especially when irrigation continues, allows biting fly populations to rapidly build up onfarm.
“Stable fly has a community footprint and just one unmanaged site can affect dozens of households and businesses up to 20 km away.
Cattle will seek relief from stable fly infestations by standing in water for long periods of time when it would normally be grazing
Check for larvae in moist dark areas of soil where there is rotting organic waste. The larvae are mobile and if exposed to light, will try and burrow.
Stable fly pupae can be found in drier parts of the soil. The pupae can range in colour from red to almost black, when the adult fly is about to emerge.
“The stable fly’s rapid lifecycle means that waste vegetable material left moist for even a few days can produce a surge of biting adults.
“When farm workers are repeatedly bitten it disrupts farm operations, productivity drops with a potential risk to health,” Mr Shepherd said.
Stable flies also target horses, cattle, sheep, working dogs and other animals, with cattle and horses being particularly sensitive.
“High fly numbers can trigger restless behaviour such as stomping, tail swishing, pacing, kicking, and bunching, increasing the risk of injury and stress.
“Bites cause constant irritation and agitation, reduced grazing and feeding, decreased productivity and impacting weight.
“Animals can’t protect themselves from stable flies, only growers can prevent the conditions that support breeding,” he said.
The Act
Under the Biosecurity and Agriculture Management Act (BAM Act) 2007*, growers and residents in affected LGAs are legally responsible to control the waste vegetation on their land to reduce stable fly breeding.
Growers can protect themselves, their animals, their neighbours, and the entire community from this painful and persistent pest by following the Stable Fly Management Plan.
Short harvesting periods save precious water and chemicals and reduces breeding sites for stable fly:
1. Turn-off water after harvest and
2. Expose waste such as stumps in the soil to the surface and
3. Mulch or chop into smaller pieces 4. Allow waste to dry on the surface
5. Dispose of reject produce promptly either by burial (1 m deep) or feeding to stock
6. Regularly monitor sites for eggs, pupae and larvae.
“When growers, government, and industry collaborate, we see far fewer outbreaks.
“Reducing breeding sites is one of the simplest, most effective ways to protect your workforce, animals and community,” Mr Shepherd said.