By Nicky Gallagher, Ph.D., Field technical manager, Syngenta Professional Pest Management
It isn’t hard to imagine why 97 percent of pest management professionals reported German cockroaches as their number one cockroach problem. Resilient and prodigious, a handful of German cockroaches can quickly become a full-fledged infestation.
Control methods shift to bait formulations
Cockroach baits have become popular over the past two decades with their targeted applications, user friendliness and easy implementation into integrated pest management plans. To keep cockroaches attracted to baits, and to avoid developing food aversions, it’s critical to know how cockroach strains respond to ingredients.
Generally, there are two main types of resistance documented in German cockroaches:
- Behavioral resistance: Some cockroaches have adapted to avoid common ingredients in baits, such as glucose. Exposing multiple life cycles of cockroaches to the same bait matrix can cause this adaptation, making the bait less effective.
- Physiological resistance: When a population of cockroaches is exposed to the same active ingredient over multiple life cycles, that population may develop a resistance to the active ingredient and mode of action.
While data is not yet available to confirm a specific rotation schedule, it is recommended to expose cockroaches to different bait matrices and active ingredients every three months to match the average life cycle of the German cockroach.
Implementing an effective strategy
A cockroach control plan should involve the following tips:
- Target the right pest: Not all cockroach species share similar food preferences and habitats. Correct identification of the species is the first step in building a targeted, effective management plan.
- Apply suitable amounts of bait: Monitoring cockroaches (pre- and post-treatment) will allow you to assess the infestation and decide if the amount of bait is for a low, medium or high infestation, and if continual baiting is required. Under-baiting can be the downfall of the best of plans, especially if you are dealing with resistant populations. Over-applying bait in lines longer than two inches, and in areas where cockroaches are not foraging, can be a waste of resources and time. For the most effective applications, always follow label directions and guidelines.
- Remove old bait: Baiting on top of old bait may reduce its attractiveness. Scrape the old bait away before applying the new bait. Evidence of old, unconsumed bait may be an indication of aversion or that bait was previously applied in the wrong place.
Advanced cockroach control
Two tools to help provide effective cockroach control as part of a resistance management plan are Advion® Evolution and Optigard® Cockroach Gel Baits from Syngenta. Advion Evolution features the proven performance of indoxacarb and offers an enhanced bait matrix that is highly attractive to cockroaches. Optigard Cockroach is powered by a unique active ingredient, emamectin benzoate, which affects cockroaches at two different target sites. This makes Optigard Cockroach an ideal partner for rotation with Advion Evolution or Advion Cockroach gel bait.
Make sure your control methods are evolving alongside cockroaches for the best results. To learn more about the latest advances in cockroach control that Syngenta has to offer, visit www.SyngentaPMP.com/CockroachSolutions.
 State of the Cockroach Market, PCT magazine, July 2016
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