Evaluating the utility of pesticide treatments aside from just following the label is part of an IPM program. Like any aspect of IPM, the treatment itself does not stand alone; it connects with all the other tools in the IPM toolbox. Whether it is as simple as a bait placement or as intensive as a fumigation, many factors will influence the effectiveness and the lifespan of a treatment.
DECISION #1. One of your first steps at any account is to determine if or when a pesticide application is necessary and if so, which treatment to use. This can be a difficult question and will depend on each individual site. This is where monitoring and the analysis of that monitoring data become essential.
For example, are the pest species numbers increasing or staying the same? Are they localized to one area or widespread? Using these data are essential as you determine when, where and how to treat. For example, for stored product pests, if your numbers are starting to creep up, maybe a fogging incorporating an IGR would be beneficial. Another example is if there is just one area where lots of insects are being picked up, maybe a crack and crevice or a targeted application of bait could mitigate the situation. If it is widespread and increasing, a fumigation might knock populations down.
Inspections will help in a number of crucial ways. Inspections will identify problem areas early while they are still small and localized, resulting in targeted treatment methods. They also will find areas lacking in exclusion. These areas can be addressed and therefore keep the pests out of the site. Sanitation issues can be found during inspections and focused on. This also will help with efficacy and monitoring.
CLEAN, CLEAN, CLEAN. Sanitation (cleaning) can’t be stressed enough when it comes to pest management. Having a master sanitation schedule is important. Poor sanitation provides an easily accessible food and water source for insect and rodent pests. Populations will rapidly increase and spread quickly throughout a site. The more sanitation can be increased, the less food is readily available. This causes individuals in that situation to develop slower, reproduce slower, and populations to be smaller and more stressed. Good sanitation also can make treatments more effective.
Scientific research has evaluated different simulated levels of sanitation. While no solid “number” can be applied to levels of sanitation, the results have shown that the less food and water material, the better. For example, consider baiting. With lack of sanitation, what is the likelihood the pests get to and consume the bait? If there is a competing food source or sources, are they more likely to go to the bait or will they feed on the other material available? In this case, proper sanitation (as defined by the master sanitation schedule), will give the pests no other options but to consume the bait.
Another example is foggings (small particles of liquid suspended in air, also called mist aerosol, ULV). Fogs are contact insecticides and must physically touch the pests. If pests are buried within built-up product that hasn’t been cleaned, how will the particles of liquid come in contact with them? Proper sanitation leaves the pests nowhere to hide, leaving them much more likely to be affected. For large commercial accounts, fumigation is sometimes required and even these fumigations benefit from good sanitation. While fumigants are gases and penetrate well, the less material there is for them to penetrate, the faster and more effectively they can do that. With densely packed products, the gas will take longer and can be more difficult to penetrate to kill all life stages.
MAKING IT LAST. Once the treatment is completed, there are ways to prolong the beneficial effects. Some methods, like baits and IGR treatments, leave behind a residual that the insects can come in contact with after the treatment. Again, check your monitoring data. When numbers just start to increase, and if appropriate for your target pest, maybe a proactive IGR would be the best choice. Keep up with sanitation. With less material potentially covering up your treatment, the more likely the pests will contact it. In the case of fumigations, such treatments leave no residue, so once the treatment is over, there is nothing to stop a new infestation from taking hold. Pay special attention during all inspections to include exclusion issues, incoming products, sanitation challenges and old product (remember: first in first out!).
Make sure you are doing these things: timely inspections, proper sanitation, exclusion, treatment when required and monitoring of the program. This results in a happy customer with minimal pest issues. It is a partnership between the facility and the PMP. Everyone working together can identify issues early and mitigate them with the least amount of interruptions.
The author is Rollins’ technical services manager.