FOCUS ON IPM: IPM Doesn't Mean "NO PESTICIDES"

Fear of pesticides often leads to strange twisting of facts. You won’t believe the misinformation about pesticide use out there in various forms of media. An article in the Journal of Pesticide Reform, 1994, Volume 14 (3), pp. 22-23, titled, “Solving Ant Problems Nonchemically” recommends boric acid as a control agent. Maybe I missed the point, but last time I checked, boric acid is a chemical. In fact, boric acid is a poison. An article in Good Housekeeping (May 2001, pp. 63-67) said, “If you’d rather avoid using chemicals altogether, consider an approach called integrated pest management (IPM)…”
“Avoid chemicals, use IPM?” What kind of nonsense is that? IPM does not — and never has — meant not using pesticides. Let’s go back to the beginning to get our facts straight.

THE CORRECT DEFINITION. The term “integrated control,” as originally defined in the late 1960s, referred to “the minimum and appropriate use of chemical insecticides to permit maximum suppression by natural control factors.” Natural control factors include beneficial insects (or other arthropods) that help keep pest insects in check.

For example, in a cotton field, there are many “good” bugs catching and eating the “bad” bugs. If you spray the field with a pesticide, you are not only killing the pests, but also the good guys. Interestingly, those bad bugs can often rebound in population numbers quicker after the spraying than the good bugs, actually making things worse than before. When entomologists first realized this, they began to advocate using the least amount of pesticides, and/or timing their pesticide application just right to minimize harmful effects on the beneficial bugs. Later, the IPM definition got tweaked a little and was published as follows:

“Insect pest management and control means utilization of all suitable techniques to reduce and maintain pest populations at levels below those causing injury of economic importance to agriculture and forestry, or bringing two or more methods of control into a harmonized system designed to maintain pest levels below those at which they cause harm — a system that must rest on firm ecological principles and approaches (Natl. Acad. Science 1969, pp. 448-449).” (Emphasis added by the author.)

Obviously, injury thresholds vary widely from pest to pest. For example, a farmer might allow X amount of bollworms per acre without having too much crop loss, but how many brown recluse spiders can a PCO allow in a house? Or scorpions in an elementary school? So, injury thresholds in the pest control industry are different from those in agriculture, but the definition of IPM is not, especially the emphasized part above.

CONCLUSION. “Bringing two or more methods of control into harmonization to maintain pest levels below that at which they cause harm” means using sanitation, exclusion, heat, cold, vacuuming, etc., in conjunction with standard chemical control means to bring about a highly effective pest control program. Not only do we need to integrate our control methods, we need to add to the program monitoring and quality assurance activities to have a basis for insecticidal treatments and to know that our efforts are working.

In this climate of litigation, PCOs need a justifiable basis for all treatments. This basis might be pest numbers on glue-boards, complaints or pest sightings noted in a pest log. In the past, PCOs have relied almost exclusively on residual pesticides — sprayed along the baseboards — to control residential and commercial pests. Those days are over. Now, we have to perform more of an investigative or educational role, and then use pesticides as a part of the overall control program.

The author is a medical entomologist for the Mississippi Department of Health, Jackson, Miss. He can be reached at 601/576-7512 or jgoddard@pctonline.com.