Baits are pivotal tools for Integrated Pest Management (IPM) for cockroaches, but applying the appropriate amount is critical for success. A recent field trial conducted by Dr. Dini Miller from Virginia Tech University evaluated two cockroach gel baits, Advion® Evolution Cockroach and Optigard® Cockroach Gel Baits from Syngenta, in multi-unit housing infested with German cockroaches. Advion Evolution, containing the active ingredient indoxacarb and an enhanced bait matrix, was used for the first three months. The bait was then rotated to Optigard Cockroach for another three months, which contains the active ingredient emamectin benzoate and affects cockroaches at two different target sites.
Following Dr. Miller’s assessment-based pest management protocol, the quantity of bait applied in each apartment unit was based on the assessment (number) of cockroaches trapped on monitors. Apartment units were categorized based on the infestation level and baited accordingly. Units with high cockroach counts received the greatest volume of bait, medium cockroach counts received less bait and low cockroach counts received the lowest volume of bait. All bait volumes were equivalent to an entire tube, half a tube or a quarter of a tube of bait.
Below is an example of the amount of bait applied after a 24-hour monitoring period, based on three Lo-Line Cockroach Trap monitors (two placed in the kitchen and one in the bathroom):
Surfaces, where bait needed to be applied, were often dirty, covered in food debris or contaminated with old bait or repellent sprays. To overcome this issue, bait was applied down the middle of small wax paper squares that had been folded diagonally (a technique developed by Dr. Miller and described in detail here). German cockroaches readily consume bait applied in wax paper and often eat through the wax paper after consuming all the bait.
Left: wax paper applied with Advion Evolution.
Right: German cockroaches consumed Advion Evolution and ate through the wax paper.
Cockroach populations were dramatically reduced without asking residents to clean up or prepare for the treatment. Considering no other form of control was used and only cockroach bait was applied, this study documents how successful baiting can be when enough bait is applied and the infestation is continually assessed.
As of May 2018, cockroach infestations were reduced by an average of 95 percent, whether the starting population was low, medium or high.
Table 1: Results over a 120-day study period. Advion Evolution was applied for the first 90 days and Optigard Cockroach was applied for 30 days. (PPMU17531)
Bait rotation, along with monitoring and assessment-based baiting of the cockroach infestation appears to be very successful in multi-unit housing. Monitors are excellent additions to any cockroach control program, as they are relatively inexpensive and effective in detecting low-level populations, and can be placed in areas vulnerable to pests like food storage rooms, closets and staff lounge rooms. They are also useful for detecting movement direction, species present, and active life stages.
By Nicky Gallagher, Technical Services Manager Professional Pest Management, Syngenta