Charles McClintock, Professional Products Business Manager at Sumitomo Chemical Australia, outlines the benefits of including an IGR in cockroach treatments. 

There are some great products for cockroach control, including baits and sprays. Using these products in combination is often the preferred treatment plan for many pest managers. However, there are several situations where the preferred combination is not the best option and indeed in some circumstances, they cannot be used at all. Many pest managers do not include an insect growth regulator (IGR) to control multiple stages of the cockroach life cycle in their treatment plan, which invariably leads to inferior treatments. It’s simple: to get the best results, you should include an IGR such as Sumilarv with all residual adulticide sprays because it does the ‘heavy lifting’.

When it comes to German cockroach control, especially in commercial accounts where there are regular treatments, resistance management is key. Being an IGR, pyriproxyfen has a different mode of action to pyrethroid and non-repellent insecticides. Not only will this help to control populations that already have a level of resistance, but its inclusion can help prevent the development of resistance, ensuring that preferred products remain effective.

If there is a concern about performance in between services, either due to duration between visits or tough conditions at the site, the inclusion of Sumilarv can keep populations in check, preventing a population build up. Pyriproxyfen is a lot more stable than pyrethroid and non-repellent insecticides and is active at very low concentrations. As such, pyriproxyfen can remain on surfaces long after other insecticides have degraded, preventing populations establishing before the next visit, by breaking the breeding cycle.

In many sensitive sites, it is not possible to use normal spray products. In such sites, when targeted use of baits may form the core element of the treatment, the use of a standalone Sumilarv spray becomes part of plan A.

Indeed, over 45% of pest managers (Pest Pulse survey, 2020) use IGRs as part of their preferred tank mix for all cockroach treatments. As mentioned previously, the unique mode of action of pyriproxyfen gives rise to a range of performance benefits. One additional example is how it can boost bait performance. Gravid female German cockroaches tend not to feed and so ignore baits when carrying their egg case. However, coming into contact with Sumilarv will prevent the egg case developing, often resulting in the female dropping her egg case earlier. Not only does this kill the developing nymphs but the female starts feeding again sooner, speeding up the bait performance.

Sumilarv as a standard inclusion for cockroach control makes sense, especially for German cockroaches and especially for commercial accounts. If you’re not a regular user, maybe it’s time to take a closer look.


Charles McClintock, Professional Products Business Manager, Sumitomo Chemical Australia