When the first cockroach bait gel was introduced in the early 1990s, it became a powerful new tool for easier control of German cockroaches, especially in food handling facilities. No longer did a pest professional need to literally treat every crack or void with a residual product. Instead, bait gel could be applied in a general area and cockroaches from sometimes many feet away would be attracted to and feed on the bait. Incorporating gel baits into the overall program with crack and void treatments and use of vacuums saved time and often produced faster results.
Today, a wide variety of cockroach bait gels are available, formulated with different food ingredients and active ingredients. Bait gels vary in color, consistency, and viscosity, depending on their formulation and moisture content. Most bait gels are fairly soft to allow ease of application from the reservoir, but a few may be less viscous or become a bit “runny” when weather is hot.
BAIT GUN TIPS. A common complaint from pest professionals occurs when bait continues to ooze from the application tip after the bait placement has been applied. This can occur when pressure is applied to the plunger in the bait reservoir or when using one of a number of available bait guns. Post-application drip is inconvenient because bait can fall onto nontarget surfaces requiring clean-up or end up inside tool pouches, bait gun holsters or tool kits.
Some high-end bait guns are engineered to limit back pressure when the trigger is no longer depressed. Other, less expensive bait guns may be more prone to drips depending on the type of bait gel. A good practice to follow is to relieve back pressure immediately after depressing the trigger by lightly moving the plunger backward or the “plunger rail” on the bait gun.
Observe the application tip upon completing the placement to see if dripping is prevented or occurring. Having a paper towel ready to wipe off any drip from the application tip is beneficial. Before returning the bait tube back to the tool pouch or tool kit, placing the sealing cap back onto the tip of the reservoir is recommended to stop any leakage and to help preserve the bait until the next time it is used.
No easy solution is available to the bait gel post-application drip issue. Preventing bait gel drips requires practice and skill along with familiarity with the chosen bait gel product and bait gun used.
Cockroach Gel Baits: Do’s & Don’ts
Because water is a limiting resource for cockroaches, it can serve as a universal attractant for these pervasive pests, particularly when used in gel formulations of baits. Stoy Hedges, B.C.E., offers the following practical tips for proper gel bait applications:
DO apply bait gels into or as close as possible to active cockroach harborages.
DON’T apply gel baits to areas where cockroaches are not likely to occur or harbor.
DO apply bait gels in smaller placements close to active cockroach harborage sites.
DON’T apply bait gels outside of cracks or to exposed surfaces in commercial food areas.
DO apply gel baits in refillable bait stations where more security or protection of bait is desired.
DON’T apply bait gels on or next to hot surfaces, such as some parts of ovens or steam tables.
DO rotate gels every 90-120 days to minimize the potential for development of bait gel resistance.
Key Identifying Characters
The American cockroach is the largest pest cockroach species in the United States, growing to just over 2 inches (53 mm) in length. This cockroach has fully developed reddish brown wings and yellowish markings on its pronotum that appear to be a “figure 8” on some specimens (Figure 1). Males and females are about the same size, but the female has a wider abdomen than the male while the male has both cerci and stylets. The wings of the male extend up to 1/3 inch (8 mm) past the tip of the abdomen while the female’s wings extend about equal to or only slightly longer than the tip.
(Source: PCT Cockroach Field Guide, Stoy Hedges)
(Left) American Cockroach (Source: USDA)
(Right) Figure 1. The yellowish markings on an American cockroach’s pronotum sometimes resemble a “figure 8” in appearance. (Photo by Stoy Hedges)