Barry Quon, Technical and Training Manager for Termseal Australia, announces the launch of a new product for cockroach control: TopBait Gold Cockroach Gel.

They might be a pest manager’s bread and butter, but cockroach control is far from easy. Particularly in a commercial environment, where the care factor for cleanliness can be low, you need good inspection skills, a good torch (or headlamp) and a reliable bait that is highly palatable. TopBait Gold is the new cockroach bait developed with a thorough understanding of cockroach behaviour to optimise performance.

Inspecting the property thoroughly before treatment is critical because every harbourage needs to be found. Whether it’s a commercial or residential situation, you need to think like a cockroach – ‘Where can I hide so I’m safe but can still access food and water?’ A thorough inspection is vital because if you miss a harbourage where a female German cockroach is hiding before she deposits her egg case, she will survive to produce over 300 offspring in her lifetime! Harbourage is one of the most important factors for cockroach survival.

As with any pest treatment, the inspection will identify the areas where the insecticide needs to be applied i.e. the locations where the pests are active and where they are harbouring. Just mixing up the liquid and spraying while hoping for the best is not much of a strategy!

There are a few scenarios that may present themselves during a commercial kitchen inspection, which provide ideal conditions for cockroach populations to thrive. Firstly, food scraps on the floor, walls and in the dishwasher. Secondly, gaps and crevices, such as between wall and floor tiles, or cracks in wall tiles. Thirdly, a hard floor cleaning machine that is grimy with food and soil residue. And lastly, clogged or dirty anti-slip floor mats such as those used under coffee machines.

During the inspection it pays to ask yourself questions as you move around the property.

Are there any inaccessible areas? In a commercial kitchen they are part of the built environment like cupboards and benches. There will also be less obviously inaccessible areas, such as in and around machinery, in the knife rack on the wall and in the legs of benches/tables or chairs.

Are there false or suspended ceilings? They might be designed to bring light into the room but lamps and skylights also provide warm, closed harbourage for cockroaches.

Are there wall openings around service pipes or conduits? Cockroaches move into the walls when the rooms are lit and busy, but once the lights are off and the activity stops they will be out and about feeding and drinking!

We can get sophisticated and use technology for cockroach detection and control but it’s important to remember the basics of cockroach biology and behaviour as this is how they have survived for centuries.

For example, cockroaches are gregarious, hiding together in cracks and crevices, venturing out to feed. They are thigmotactic, meaning they prefer hiding in cracks and crevices where they can touch surfaces on two or three sides. The smaller the cockroach, the smaller the crevice; German cockroach nymphs can hide in cracks just half a millimetre wide.

If the harbourage is full because the population is high, they will be seen on walls and ceilings during the day or when the lights are on. They are mostly active after dusk or when artificial lights are turned off.

To keep themselves alert, cockroaches groom themselves to clean their antennae and legs so they can ‘smell’ and ‘hear’ efficiently. They have sensors in their antennae for movement as well as for finding a mate and tasting food. Being omnivorous, they eat both fresh and decaying organic matter. If they can find a food rich in carbohydrate, protein and fat that’s all they need.

A good cockroach bait needs to be highly palatable in the face of competition from other food sources. TopBait Gold is an Australian-made cockroach bait that has been especially developed for the tastes of Australian species under Australian conditions. It can be used as part of an insecticide group rotation because of its active ingredient, hydramethylnon. It is effective for cockroach management because TopBait Gold has been formulated to exploit natural cockroach behaviours including their habit of coprophagy (eating faeces), emetophagy (eating vomit) and cannibalism (eating each other). In a similar way to trophallaxis, which we are familiar with in subterranean termites, these three behaviours can result in the bait – and therefore the active ingredient – being rapidly spread throughout the cockroach population.

With diligence, patience and a great bait, successful cockroach control is certainly achievable.


Barry Quon, Technical and Training Manager, Termseal Australia