Carole Cast from Syngenta’s PPM team suggests two ways of dealing with the inevitable post-flooding cockroach issues.

It’s hard to ignore the rain that has inundated the east coast of Australia in the last few months and the impact it has had not only on trying to get treatments done but also on pest behaviour.

During a rare moment of sunny weather, I recently drove to the picturesque Hunter region of New South Wales, which has recently seen more than 400 mm of rainfall. We found the perfect table with resplendent views and our waitress placed a fabulous antipasto platter before us. But then the screams started. The platter went flying and we jumped up in shock. A giant cockroach had scuttled along the edge of the waitress’s linen skirt, causing havoc in the restaurant – the last place you want to see a cockroach.

After so many major rain events, we shouldn’t be surprised to see a smoky brown ruining a lovely outdoor lunch. Rain means more moisture in entertainment areas, which triggers insects – ants, spiders, flies, fleas and mosquitoes – to breed, especially when the weather is still warm and humid.

This means that within two days of a torrential downpour, outdoor spaces such as hospitality areas, entertainment quarters and gardens should be thoroughly treated for pests. When insects (even flying ones) land on the treated surface, they collect the active chemical on their exoskeletons, groom themselves and can ingest the lethal dose. Crucially, the more treated surfaces there are, the less chance pests have of survival.

Outdoor surfaces that may be treated after heavy rain include: hard surfaces, paying close attention to the underside linings of sheds, huts and gazebos as this is where insects are most likely to shelter; under tables, barbecues and outdoor furniture; in wall linings, around door frames and window entries; and around the base of buildings, garden sheds, paths and garden edging.

If your commercial customer already has a regular treatment plan, it would certainly be advisable to do a treatment top-up after rain. Residuals can be greatly affected by prolonged wet weather, making them less effective in the long run.

For customers dealing with a deluge of insects after unseasonable rain, and for the cockroach scenario mentioned above, Advion Cockroach Gel and Demand Duo Insecticide are great options.

Advion Cockroach Gel is a bait solution that is highly palatable to a wide variety of cockroaches, including German, American, Australian, Oriental and of course, the smoky brown. The gel formation makes Advion ideal for treating harbourages, cracks and crevices in outdoor entertaining areas. The use of indoxacarb – an active ingredient with a unique mode of action – unleashes a chain reaction that can eliminate hidden populations. Advion is also HACCP certified, so it is a great choice for hospitality and food handling environments where a sensitive product is needed.

To control a wider range of pests, Demand Duo is a general pest spray that provides simple and effective control against cockroaches, ants, flies, fleas, paper wasps and spiders. The unique ZC formulation combines a suspension concentrate of thiamethoxam with a capsule suspension of lambda-cyhalothrin to form a powerful single solution. Demand Duo is also easy to use, low odour (ideal for entertainment areas with patrons) and versatile enough to be used on porous and nonporous surfaces. Of course, read the label prior to use.

The end result? Satisfied customers and fewer callbacks for your business – even after it pours.


Carole Cast, Business Manager, Syngenta PPM

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