During winter, the life stages of stable fly (eggs, larvae and pupae) remain inactive in soil where there is decaying organic material. While stable fly activity may appear low at this time of year, these life stages are simply waiting for warmer conditions to resume development.

Supplied by Department of Primary Industries and Regional Development

PETER Spackman, CEO of vegetablesWA said “killing these life stages now, using Integrated Pest Management (IPM) strategies will dramatically reduce the number of flies that will breed in spring, and in future seasons.”

“Fewer flies emerging early in the season means smaller, more manageable populations later, with long term benefits for growers and neighbouring communities.”

“If growers miss this opportunity, stable fly numbers will increase rapidly once temperatures rise. Large breeding populations established in spring are far more difficult and costly to manage through the warmer months and will lead to even larger populations the following year.”

“Proactive management over winter is especially important in areas where stable fly is a declared pest and must be controlled. Dandaragan and

Victoria Plains have recently been added to the list of local government areas where obligations to control stable fly apply.”

May to August

Immediately (within 3 days) after harvest:

1. turn off irrigation

2. expose waste material in the soil such as stumps

3. mulch or chop waste material into smaller pieces

4. allow waste to dry on the surface

5. weekly inspection of soil for eggs, larvae or pupae and if found, use an approved insecticide.

Reject produce Within 3 days:

■ either bury (1 m deep) or

■ feed out to stock.

By using IPM to suppress stable fly breeding now, growers can:

■ reduce future stable fly populations

■ reduce insecticide use later in the season

■ delay the development of insecticide resistance and

■ protect beneficial insects that support crop production.

“Plant material left on the ground for more than 3 days after harvest creates a perfect breeding environment for stable fly. Samples collected from commercial vegetable growers have shown that over 1,000 stable flies/m2 can emerge from the soil after harvest, particularly from the residues of broccoli, cabbage, cauliflower, celery crops”.

“By using IPM practices now where organic waste mixes with the soil — vegetable growers can reduce the risk of spring stable fly infestations and help limit the impact of stable flies on your workers and the surrounding community,” said Mr Spackman.

Cattle can suffer serious irritation and stress from stable flies.

For more information or any questions, please email stablefly@dpird.wa.gov.au

DPIRD — Stable fly management www.dpird.wa.gov.au/stablefly

* Under the Biosecurity and Agriculture Management (BAM) Act 2007, landholders in areas where stable fly is a declared pest have a legal obligation to actively reduce stable fly breeding on their property. These areas are the cities of Armadale, Cockburn, Kwinana, Rockingham, Swan, and Wanneroo and the shires of Capel, Chittering,

Gingin, Dandaragan, Harvey, Kalamunda, Victoria Plains, Serpentine–Jarrahdale and the portion of the Shire of Murray described as the Peel-Harvey Coastal Plain Catchment — State Planning Policy No. 2.1.