Understanding Pest’s Resistance to Pesticides
Biological pesticide resistance occurs when a given pest population becomes genetically more able to withstand effects of a pesticide.
Over time as the resistance increases, it can result in the pesticide being ineffective against that pest. It is important for the pest management industry to be aware and manage this as much as possible, so we can maintain the tools of our trade.
Here’s how it works; survival of the fittest.
Out of a population of 100 insects, let’s say two are genetically “stronger” against a chemical. If we treat that population, those two will survive plus some others probably, but for sure the “weakest” will die. The survivors have babies that will carry their “strong” genes. Multiply this by many more applications over many decades of time and now the remaining population overall will be “stronger.”
Resistance can be managed. Proper applications alone will prevent or slow down the development of resistance.
The biggest contributor historically is believed by most in the industry to be inadequate doses. It’s common to use less material or cut short the time needed for an application to save money or time.
Another strategy to reduce resistance is to use a material that kills in a different way. The chances of an individual being resistant to both types of pesticide are rare. This strategy can be used as a preventive but also to reverse highly resistant populations in certain geographic areas.
Focus on the area where the resistant insects occur and switch to the other pesticide. Over time, less resistant insects will eventually enter the area and breed with the local population essentially diluting it with “weaker” insects.
The most important thing to remember is that we can manage resistance by simply doing a good job when we apply pesticides.