Critiquing insecticides as a last resort

Pesticides may not always be the worst environmental choice
when considering pest control options, according to a
recent scientific society position paper.

Two weeks ago I wrote about a recent position paper by the Entomological Society of America and its sister societies, American Phytopathological Society and the Weed Science Society of America. The paper critiqued some popular integrated pest management (IPM) concepts, including the idea that IPM programs should use only "least toxic" pesticides.  The same paper also addressed the widely adopted idea that pesticides should only be used "as a last resort" in an IPM program. Today I wanted to elaborate on use of pestcides as the last resort.

The concept of "last resort" pesticides is tricky because it's meaning is open to different interpretations. On the one hand, using pesticides as a last resort could mean that pesticides are used only when pest numbers or damage from exceed some pre-determined threshold. The use of thresholds is usually invoked in combination with a pest monitoring program and with an integrated control strategy including non-chemical tactics such as habitat modification, sanitation and quarantine. This is a proven IPM approach that has been used since the earliest days of IPM.  As the Societies' position paper points out, however, this is not the only possible interpretation.

Many agencies and regulators have interpreted the "last resort" imperative to mean that when a pest problem occurs, all non-chemical controls must first be attempted. Only when all else fails, should pesticides be considered. There is a subtle but important difference in these two interpretations. In the latter case, thresholds are made secondary to a process of trying first one non-chemical control, then another and then another, before finally turning to a pesticide. Such delaying tactics, according to the statement, can lead to unacceptable pest buildups and damage.

From my perspective, this approach was used last summer in my community during an outbreak of mosquito-borne, West Nile virus (WNV). While medical doctors in our city were worried that too many human cases of WNV had already occurred, and that aerial pesticide spraying was needed break the epidemic, those in the community with deep misgivings about pesticide use were insisting that not enough had been done in the areas of public education, breeding site removal, and larvaciding. They requested that the cities and county wait until everything that could conceivably be done before resorting to spray planes.  They were essentially invoking the "last resort" concept.

While this approach may seem reasonable on the surface, it's consideration resulted in delay and ultimately nearly 400 (serious) human cases of the virus in my county alone.  A predetermined threshold (say, to commence aerial spraying when education, source reduction and ground sprays fail to prevent mosquito infection rates from reaching levels likely to result in human cases) would have alerted the community that preventive tactics had already failed, and more aggressive controls were needed.

The ESA position paper provides links to a number of similar cases where following the "last resort" approach led to out of control pest problems and higher control costs. Many of these examples illustrate that waiting to control a pest may result in missing the ideal time to treat, and may ultimately result in the need for higher concentrations and more applications of pesticides to control a pest infestation.

Finally the position paper points out that the "last resort" concept implies that pesticides are always the worst choice, which is not true. Non-chemical techniques are sometimes more expensive, require more labor and energy, and result in lower levels of control than chemical pesticides. An example cited from Texas was conventional tillage to control weeds in arid farmland.  A study showed that herbicide use not only was more effective in conserving critical water, but it was less costly.

Rather than talking about "using only least toxic pesticides as a last resort", I believe we remain truer to the original spirit of IPM if we talk about "minimizing risks" and "using pesticides only when necessary" to prevent or control damaging levels of pests. Integrated pest management has never been easily distilled to a simple formula or prescription.  Each pest and situation is unique and deserves a flexible approach to do the right thing. This flexibility of IPM is both its greatest strength and, perhaps, its greatest weakness.  Flexibility is a weakness because IPM is difficult to codify, and develop rules for that fit all situations. But flexibility is a strength because IPM is adaptable to many settings--not just agriculture for which it was originally developed.

TDA meets with its advisory committtee

While the bright lights and news cameras focused on Austin politicians introducing their latest bills at the 83rd Regular Legislative Session, the Structural Pest Control Advisory Committee met quietly this week with leaders of the Texas Department of Agriculture's Structural Pest Control Service.  The focus of the meeting, as always, was to provide TDA administrators with feedback on new ideas for how to streamline operations and minimize pest and pesticide risk to the public.

The flu season may have explained the low turnout at this quarter's meeting (the first time I recall no public comments), but committee members still found stuff to discuss, especially with regard to the first draft of TDA's proposed penalty matrix.

So what's a penalty matrix? It sounds boring.

I guess a penalty matrix is pretty boring unless you're the one being penalized. The SPCS has always used some form of matrix, or chart, to assign penalties to different possible violations of the Structural Pest Control Act and its regulations.  Under the law, the TDA Administrator is given leeway in assigning penalties to violators, up to a maximum fine of $5,000/violation/day and/or license suspension, revocation or denial. The matrix provides a transparent and objective means of pre-assigning penalties for different violations.  While not constraining the Department from giving a higher or lower fine, it sets guidelines for fair penalties if you, say, fail to provide an inspector with a valid applicator's license.

The draft guidelines list approximately 70 possible violations and puts each into a table of low (S1), medium (S2) or high (penalty) violations.  Within each of these three tables an offense can be categorized as minor, moderate, or major. Penalties increase in each of these columns from the first to third instances of violations over a five year period.  So there are three tables, each with three rows and three columns of penalties.

For example, failing to have your company's TPCL number on any vehicle in which you do pest control business is considered (in this draft) to be an S1-Moderate violation. You would expect to receive a $150 fine for a first violation.  That fine would increase to $300 and $450 fines for the second and third violations.

Moving up the scale, failure to provide an accurate or complete WDI Report is an S2 Moderate violation, worth $750 for a first offense.  Operating out of category (say doing weed control without a weed license) is considered an S3-Moderate offense, and will cost you $1000 for a first offense.

While assigning penalties to a long list of crimes may sound a little like a job for Les Miserables Inspector Javert (Russell Crow in the latest movie musical version), having the matrix is to everyone's benefit. It makes the TDA's job easier and more objective, and it adds transparency to the process. Anyone can look up the matrix online and know exactly what to expect for a given violation.

The committee's job in all of this? Review all the assignments and penalties and give our input. It's not as fun as it sounds.

Perhaps the most upbeat news to come out of this quarter's meeting was the announcement that TDA has decided to contract out its examinations to a private firm.  PMPs should see some immediate benefits such as lowering of fees from $75 to $64 per exam. In addition, the number of locations will increase from 13 to 23 offices around the state.  Exam locations will no longer be associated with TDA or other government offices.  And sites will be open five days per week, with registration open 24/7.  This should speed up the process of getting new licensees on the street considerably.  The only down side to the announcement is if you are computer-phobic.  All exams will be online and you will receive score feedback immediately.

The committee also discussed ways that TDA could better reach the public with a simple message that when hiring someone to control pests, make sure they are licensed and qualified. One of the ideas proposed was to make that official message available through the many pest control company websites around the state.  Look for TDA to come up with creative ways to get the word out to the public about the value of your pest control license and your training over the next year.  They may be contacting you for your company's help.

A critique of the IPM gospel

The three largest U.S. scientific associations with strong professional connections to integrated pest management (IPM) recently posted a news release that should be of great interest to anyone in the business of pest control. The Entomological Society of America, Weed Science Society of America, and American Phytopathological Society published a position paper last November that, while it has not received a lot of attention in the press or the industry (let's face it, IPM is not the sexyist topic), takes careful aim at some favorite concepts embraced by the  IPM community.  While the statement may read like heresy to some IPM supporters, I believe their arguments are well-thought out, and worthy of consideration by everyone with a stake in pest control.

First, a little historical background.  The IPM concept was first embraced by agricultural scientists, and later by those involved in urban pest control. The earliest versions of IPM emphasized the use of both chemical and biological methods of pest control. As IPM matured, it accepted that the judicious use of pesticides was desirable, as long as every effort was made to minimize the environmental and safety impacts of pesticide use--an approach still followed by most of those in production agriculture.  

As IPM evolved it was embraced by the environmental community and by regulators, and eventually by urban pest management professionals. Along the way IPM jargon, and the way it was implemented, also evolved.  One of the most influential modern attempts to articulate the IPM concept for human-occupied structures was the 1993 EPA publication, Pest Control in the School Environment: Adopting Integrated Pest Management. In this publication (painstakingly crafted by environmentalists, the EPA and the National Pest Management Association), the judicious use of pesticides was endorsed as long as the "least toxic and most effective and efficient technique[s] and material[s]" were used. This seemed to be a compromise that all parties could live with, and everyone seemed happy.

Over these past twenty years the idea that "least toxic methods" should be part of the definition of IPM has reached the status of gospel. The term "least toxic pesticides" and "least toxic methods" is ubiquitous in IPM policy statements and even governmental rules and regulations. Its authority is rarely challenged by industry, academia or politicians--after all who wants to argue that schools or government agencies or your local PMP should use anything but the least toxic products?

Most of us have been taught to avoid "rushing in where angels fear to tread", but that's just what these three societies did by taking a stance against the "least toxic pesticide" concept.  It's not that my scientific colleagues are against the use of low toxicity pesticides, their argument is with the increasingly common insistence that "only 'least toxic pesticides'"' be used in IPM programs.

I encourage all to read the statement, but their objections boil down to the following:

• The term "least toxic" is too imprecise, and subject to misinterpretation by the public and by professionals alike. I can personally attest that many people wrongly equate "least toxic" with "organic" and "natural" (neither of which have any necessary connection to the least toxic concept--many natural chemicals are highly toxic). 
• Toxicity is not the same as "risk". An active ingredient can be highly toxic, but when diluted or made into a formulation that is highly unlikely to result in a human exposure, its use can be low risk. What consumers and regulators and parents should be most concerned about, when it comes to pesticides, is risk. 
• Least toxic to what? If an insecticide is low in toxicity to bees is it necessarily low in toxicity to dogs or humans or song birds? The least toxic concept presumes that pesticides fall neatly into a gradient of products range from those low in toxicity to everything to those that are high in toxicity to everything. They don't. 
• If only the least toxic products are used, this limits what can be done to manage pesticide resistance. A policy that rejects the possible use of 90%, say, of the available pesticide products leaves a much depleted tool belt, increasing the risk of pests developing resistance to the one or few remaining products. 
• The least toxic products are not always the most effective products. Indeed, if toxicity is the main selection criterion, then effectiveness is by necessity relegated to a secondary role. In many cases this means more applications of the least toxic product will be needed. Fuel, labor, pesticide exposure times and materials costs (none of which are environmentally desirable) will always increase with the need for more frequent pesticide interventions.

In case you think this is much ado about nothing, consider the wording of the Texas Occupations Code where it lays out the requirements for school IPM in my state.  The language of this code has been used as a model for other states' IPM regulations.  It directs the state to "include in standards adopted under this section: (1) a requirement to use the least toxic methods available to control pests, rodents, insects, and weeds..." The potential negative impacts of this language were blunted when Texas state regulators adopted a liberal set of regulations that allowed use of any pesticide in schools, but required schools to justify in writing the use of products identified as higher risk pesticides. In practice, this soft-handed approach has resulted in schools using lower risk insecticide approaches, without restricting choices. Other states and communities have seen regulatory language not so friendly to pesticide choice.

I have great sympathy with policy makers trying to encourage homeowners and pest management professionals to use the lowest risk, effective pesticides.  On the other hand, I agree with the ESA/WSSA/APA critique of the "least toxic" concept. The hard part is coming up with better approach that encourages pesticide applicators to use good judgement when selecting pesticides and pesticide formulations to supplement biological and other non-chemical controls.

For their part the societies point readers to the National IPM Roadmap as a source of guidance. The Roadmap was developed ten years ago and used as a guidance document by the USDA in developing a national plan to improve and encourage the adoption of IPM. Significantly, this roadmap does not use the term "least toxic" or "use of pesticides as a last resort", but emphasizes IPM as a process that identifies and reduces risks from both pests and pest management related strategies (including pesticides).

The second target of the society position paper is that idea that pesticides should be used only as "tools of last resort". But that will be the topic of another post.