For the purposes of this Pest Perspectives column, I am going to focus on the German cockroach (Blattella germanica). Cockroach management seems to have taken a turn in treatment methodology. Yes, there are some traditionalists and likely some that have their own special blend of unique tips that seem to work for them. I have learned that you cannot really tell somebody how to do cockroach work, because they may listen, but they know their method is better than yours. This is long-standing perceived fact. Everybody is, in their own eyes, the best cockroach killer on the planet.
METHODS. Your method, which is obviously the best one and I would not dare to disagree, may be a standalone action or may include a variety of integrated choices. If we survey the product offerings for cockroach control, we have non-chemical options like glueboards or vacuums, dusts, stations, gel baits, non-residual and residual products. There are aerosols, liquid ready-to-use and liquid concentrates. You may even be making choices between the adjuvant parts of the formulation. Is it water-based, oil-based, suspension concentrate, microcap or flowable? Even further down the rabbit hole is the active ingredient and its mode of action. It seems that the options and combinations are endless! Maybe there are too many options and we as an industry have gotten lost in the myriad of potential only to lose sight of the end game, effective cockroach death. There are some basic steps that should be followed for management. Some may argue that not all of these are essential, but I believe time has proven that while control can be achieved without following all the recommendations, control will be a longer process.
BACK TO THE BASICS. Successful cockroach management should focus on IPM. Basic elements like sanitation and harborage reduction are good starting points. Food competition can be a major factor in bait acceptance or rejection. German roaches like to squeeze themselves into tight places, so any opportunity that you can seal a gap or create more space between objects will help to eliminate access and hiding. Inspecting for excess moisture, plumbing leaks, or improper drainage can be a major factor in success or failure. The elimination of these basic necessities for life put strain on the population and will ultimately increase the success of the overall management program. I’m not going to sit here and tell you that you can eliminate a German cockroach infestation with just habitat modification, but I will say that these actions will make the elimination easier, quicker, and possibly help to prevent a recurrence in the future. Some level of chemical input will likely be needed.
STRATEGY. I have seen an alarming trend towards fogging. Not just space fogging, but crack and crevice fogging. These often get branded a “clean out” and the servicing technician goes into an infested account and fires up a ULV fogging device. There does not seem to be any integrated approach, no thought process on habitat modification or sanitation. This methodology is destined to fail. There will be some cockroach carnage, but there are almost assuredly cockroaches escaping deeper into voids or even resistant strains recovering from their pyrethrin-induced stupor.
I am a huge proponent of vacuums. There has never been a recorded case of cockroach vacuum resistance. The debate will rage on about the need for HEPA filtration, respirators, dust masks and environmental contamination, but the jury has ruled on the fact that you should protect yourself from breathing cockroach debris. If you can use a HEPA-filtered vacuum, do it. If not, wear some sort of filtering face piece to keep safe. Vacuums impact a population. They remove adults, nymphs, dropped oothecae, and will assist in removing dust or food debris. It seems like a no brainer considering it is also a non-chemical option. Any non-residual flushing should be combined with a vacuum so that population spread is limited.
After an intensive flush and vac, it is time to move on to residual treatments. Consider dusts to make long-term residual treatments in areas protected from moisture or access. Baits are good options, but food competition must be considered. Bait aversion and resistance can become an issue if bait rotation is not part of the program. If you have been experiencing a decline in the effectiveness of your control program, consider a change in mode of action and bait matrix. Talk to your technical team, distributor or manufacturer about options if you are not the most experienced in this area. Resistance management is one of the most important responsibilities of our industry, second only to safety.
No matter what your cockroach management protocol entails, it needs to be based in IPM. Without consideration of the habitat, and removing basic needs, there are endless challenges to overcome. While these may not be insurmountable, they will definitely cause delays and frustration for both the customer and the servicing professional.