By Tim Husen, Ph.D., technical services manager, Syngenta Professional Pest Management
“Why isn’t this stuff working anymore?” I’ve heard this many times over the years from pest management professionals dealing with recurring German cockroach infestations. Nine times out of ten, “the stuff” they are referring to is a spray or bait product. My response to this always focuses on three German cockroach management principles:
- Inspection: Are you looking in the right places?
- Monitoring: Are you assessing your populations?
- Rotation: Are you dealing with bait aversion or insecticide resistance?
If German cockroaches persist after previous control measures, then re-inspection should be your starting point. Inspections establish management focus zones and build customer partnership on sanitation and breeding habitat exclusion.
Consider if there are inaccessible locations that were not previously treated and identify harborage sites that cockroaches may have relocated to. Eliminating harborage options and reducing the amount of competitive food resources stresses and decreases cockroach populations. This will often make baiting management programs even more effective.
Next, assess the effectiveness of your program. Monitoring is just as important as inspection and treatment. One assessment method is monitoring catches using glue boards. By giving you an insight into the number of cockroaches, monitors provide a snapshot of cockroach activity since your last account service.
Keep an accurate record of inspection time, monitor locations and catch numbers in service report documentation, otherwise you’ll be unable to accurately interpret population trends over time. Monitor results are much more than just a number. Look at the populations you’re trapping and dig deeper into what you can learn about their location, numbers and habits.
When cockroach populations persist despite control efforts, it’s easy to assume “these cockroaches aren’t eating my bait” (bait aversion) or “this spray isn’t working anymore” (insecticide resistance). The easiest way to rule out these possibilities is to focus on product rotation. The SecureChoice℠ Cockroach Assurance Program provides an excellent programmatic template that mitigates these potential pitfalls. Quarterly rotation of active ingredients with baits, residual sprays and food matrices with gel baits slows the likelihood of resistance building up in cockroach populations.
Dealing with persistent German cockroach infestations is tough and often requires a program reset or refocus. Combining inspection and re-inspection, monitoring populations and rotating products are the best paths to success!
For more information on proven cockroach control visit SyngentaPMP.com/Cockroach.
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