Where Does Insecticide Resistance Come From?
Insecticide resistance in arthropods is a serious problem that costs farmers millions, if not billions, of dollars each year, writes Andrei Alyokhin at CropLife. According to the online database maintained at the Michigan State University, worldwide resistance has been reported to 433 different insecticides. In the U.S. alone, 234 different insect, mite, and tick species became resistant to at least one chemical. Furthermore, these numbers, as impressive as they are, likely underestimate the true extent of the problem. Despite all the efforts of people who maintain the database, not every case gets entered into the database, or even becomes known to people outside of the farm where it happened.
Some pests are resistant to a single compound; however, many of them are simultaneously resistant to several related, or even unrelated chemicals. New cases of resistance are being continuously detected in a wide variety of crops, and commercial growers can never assume that it will not happen on their farms.
Practical significance of insecticide resistance is widely acknowledged. Numerous scientific papers and extension bulletins are published on the subject, presentations are being delivered at a variety of conferences, and grants are being awarded by government agencies in different jurisdictions. There is even a standing committee, comprised of the representatives of major pesticide companies and aptly named Insecticide Resistance Action Committee. Yet, the problem remains, and arguably even getting worse. So, what is going on?
What Is Insecticide Resistance?
To answer this question, it is important to first understand what insecticide resistance is. A good place to start is defining what we are trying to understand, an approach that is also helpful in many other situations in life. While this seems like a no-brainer, the issue was contentious for a while, and there are still some differences in opinion. An academic definition describes field-selected resistance as a genetically based decrease in susceptibility of a population to a toxin caused by exposure of the population to that toxin in the field. In other words, it is not the same population now than it used to be, and it is likely to stay this way at least in the near future.
Get The Newsletter Today!
