Integrated Pest Management (IPM) is a term that confuses some people. Ironically, what may be confusing is that these three words mean just what they say: the coordinated application of different techniques to control pests. It’s a matter of which techniques we apply and how they are applied that provokes questions and even controversy.
Many in the pest control industry consider IPM to be common sense. This is too brief a description but a good place to start. However, if IPM is common sense pest control, then why use the term at all? Short answer: because some pest control isn’t IPM. There are still pest control companies that rely too much on chemical pesticides, including those that are toxic to pets, wildlife and even humans. Of course, these companies must follow the same state and federal pesticide safety laws that IPM providers also follow. However, there is more to pest control than knowing and following the legal application of each pesticide
IPM integrates pesticide use into a plan that identifies, monitors and controls a pest population. In an IPM plan, pest control technicians consider the precautionary principle: if an action has a possible harm, then the burden of proof that it will be safe falls on those taking the action. While this sounds like old fashioned responsibility, it was only in the 1990s that the precautionary principle became a common factor in policy making.
The beginnings of IPM go back further. Even before Rachel Carson’s groundbreaking book Silent Spring was published in 1962, some scientists and farmers were questioning widespread use of synthetic pesticides. Opponents of Integrated Pest Management sometimes stereotype its advocates as deskbound bureaucrats, political activists and even starry eyed hippies. But over a century ago, the debate among mosquito abatement technicians as to the best way to decrease mosquito populations showed that the controversy surrounding chemical methods is not a new one.
Then, one group of the “mosquito warriors” advocated covering marshes and swamps with petroleum while others advocated draining the wetlands by ditch digging.
But it was in the years after World War II, that IPM’s roots were planted in the cotton farms of the Deep South and California’s Central Valley by farmers and entomologists. There they developed such practices as monitoring pest populations and specific, targeted use of pesticides.
It was also at this time that the chemical pesticide industry began a postwar boom, finding new customers in agriculture and in the expansion of the pest control industry. For customers and even many technicians, pest control became synonymous with chemical pesticide use at the expense of other methods such as monitoring, prevention and selective use of pesticides. Nevertheless, the principles discovered on the farms developed to form the philosophical and practical foundations of IPM.
By the late 1960s, two separate phenomena converged to bring IPM to the attention of pest control technicians and their customers. First, was the ongoing development of IPM.
The second phenomenon that brought IPM to the public eye was the emergence of the environmental movement. Americans read Silent Spring, a shocking indictment of the chemical pesticide industry by the biologist Rachel Carson. Not only did Silent Spring awaken the nation to the dangers of the unrestricted use of pesticide, it sparked a concern for all environmental issues. Simply put, attention to the pesticide issue reinforces concerns for the whole environment and vice versa.
With the development of IPM and the rise of the environmental movement, IPM came to be implemented in more and more pest control programs. Research in the lab and success in the field confirmed IPM as a viable pest control method. By 1972, conservative Republican President Richard Nixon directed federal agencies to implement IPM wherever applicable.
1. Like many vocational methods, IPM is a continuously developing practice. However for many years, the following principles have been recognized as the logical foundation of IPM. Inspection and establishing an action threshold population. The major goals of the inspection are to identify if any pests are present and, if so, their population, life cycles and what conditions cause their infestation. Such conditions include availability of food and habitat. To pursue a pest control program, the customer should know the action threshold population, i.e. the number of pests necessary to initiate pest control. In agriculture, finding a threshold population is relatively simple. Does the economic damage inflicted by the pest exceed the economic cost of pest control ? If so, then it is in the farmer’s economic interest to control the pests. However, in household or other urban settings this becomes more complex. A single rat in the baby’s bedroom is an obvious action threshold population but one or even a few in a backyard shed might be tolerable however undesirable. A swarm of roaches in a restaurant is probably a threshold but in a large apartment building the owner may endure a small population in the basement. The importance of inspection can never be overestimated. As the Purdue Course in Advanced Level Urban and Industrial Integrated Pest Management emphasizes: “the flashlight is the most important piece of equipment in the pest control industry.”
2. Preventive cultural practices. Here the technician advises the customer what methods can serve to deter or even eliminate the pest. In some cases, an improvement in hygienic practices or structural repairs can be enough to stabilize, then reduce the pest population.
3. Monitoring. The inspection indicates the level of pest infestation. Followup monitoring can determine how well the IPM plan is succeeding. Monitoring traps help the technician assess the pest population while also reducing it. Competent monitoring not only informs if the IPM plan is decreasing the pest population, it also indicates which methods work and how. Like cultural practices and other IPM methods, monitoring is best done in cooperation with the customer.
4. Mechanical controls. When a pest problem reaches an action threshold, IPM providers use mechanical controls as their first option. As mentioned above, some traps double as both monitors and pest killers. Other mechanical controls include barriers, vacuuming and “getting down and dirty” enough – as one veteran technician described the job – to hand pick pests.
5. Biological controls. Beneficial organisms, such as certain bacteria, spiders and some insects, can reduce pest populations with low environmental and economic costs. While these predators can safely decrease a pest population, they may present problems, especially in residential areas. Also, Bt, diatomaceous earth and other organic materials are legally classified as pesticides. While safer than most synthetic chemical pesticides, even organic materials may be unsafe in some quantities or circumstances. Accordingly, pest control technicians still follow state and federal regulations and other safety precautions regarding these materials.
6. Chemical pesticides. Synthetic chemicals are the last resort for an IPM provider and must be used with consideration of all their consequences, not just their effectiveness in combating the pest. And because pesticides are classified by safety levels (from Caution to Warning to Danger), IPM technicians prefer using pesticides labeled Caution. Pesticides labeled Warning or Danger are rarely and selectively used in IPM.
But the issue of pesticides is not just about the safety of a specific chemical. The issue also involves the accumulation of pesticides and other toxins in our air, water, soil, food, work places, homes and bodies. Individually, a toxin may have little effect; cumulatively their impact may be immense – and remains little understood.
IPM is a developing practice that has already discovered numerous and innovative methods to control pests while making ourselves and our environment safer. The problems IPM providers face will change as pests continue to adopt to human society. As long as there are human beings we will attract parasites. We will continue to try to kill or keep them away and they will try to adopt to our control methods. IPM always seeks to build a better mousetrap, one that only harms the pest and not the person or environment.
By Howard Williams