[Market Opportunities] A Wave of the Future

e’ve come a long way since Delbert, the PCO in the movie "Arachnophobia" used the "stuff that smokes" to control a plague of invincible spiders. PCOs don’t have the "good stuff" out in the truck anymore. Nothing we use smokes when sprayed — there’s not even a fizzle. In fact, we’re faced with more and more restrictions on pesticides at both the state and federal levels.

In response, some PCOs have turned to so-called "natural pesticides" to avoid pesticide-use reporting laws and to please their chemophobic customers. But what exactly are these environmentally friendly, natural pesticides that people call "green pesticides"?

Many PCOs summarily dismiss the whole idea of natural pesticides, thinking to themselves how foolish it is to try to control pests with things like garlic, soybean oil or orange peels. However, no matter what one thinks about the "greens," their role is expanding in our industry simply because the public is asking for such products. What is a green pesticide? What is the place of such products in the pest control industry?

WHAT’S CONSIDERED GREEN? Just exactly what constitutes a natural or green product varies depending upon where you are or who you’re talking to. Plus, there’s lots of misinformation out there. I’ve heard PCOs say things like, "We don’t use anything toxic . . . just stuff like boric acid, rosemary oil, d-limonene and diatomaceous earth."

To that, I would say, "OK, then eat you a cup of boric acid tonight and see if it’s non-toxic, or breathe you a big snoot-full of diatomaceous earth and see what it does to your lungs."

Sure, these things are considered to be of low toxicity, but they are still somewhat dangerous if misused. There are reports in the scientific literature of contact dermatitis and occupational asthma from exposure to rosemary oil, as well as necrotizing dermatitis with sloughing of the skin following exposure to d-limonene. So we need to be careful what we say about how "safe" something is.

Yes, there are certain active ingredients in minimum-risk pesticide products that are essentially non-toxic and totally exempt from the Environmental Protection Agency’s registration process. But other green pesticides are one step above that and are registered with the EPA as reduced-risk products.

WHAT MEANS WHAT? A few definitions are in order:

Biopesticides. This general term means pesticides that are derived from natural materials such as animals, plants, bacteria and certain minerals. For example, canola oil and baking soda have pesticidal applications and are considered biopesticides. According to the EPA, at the end of 2001, there were about 195 registered biopesticide active ingredients and 780 products.

Minimum-risk products. Certain natural insecticides are considered minimum risk compounds by EPA and do not require federal registration (under FIFRA). Active ingredients in these products are often found in foods and include things like clove oil, garlic, linseed oil, mint and sesame. Further, in most states, these products are not considered pesticides, so posting, notification and reporting laws do not apply.

Reduced-risk products. Some green products are EPA-registered as biopesticides but are classified in the category "reduced-risk" pesticides. These compounds are considered naturally occurring and include things like plant essential oils (such as limonene and linalool). Interestingly, in regard to reduced risk products, the actives are usually exempt; it’s the inert ingredients that do not appear on the FIFRA 25 b2 lists, therefore, making them reduced risk.

Many reduced risk pesticides contain other naturally occurring botanical ingredients such as neem seed extract, pyrethrins or rotenone, all of which have proven insecticidal qualities. For example, neem tree seeds contain azadirachtin and liminoids that upset insect hormonal systems, preventing them from developing to the adult stage.

We are all aware of the effectiveness of pyrethrins against insects. Often, these reduced risk pesticides are a combination of several botanical compounds. For example, a product called Diatect V is a blend of natural pyrethrins and diatomaceous earth. Take Down Garden Spray combines pyrethrins and canola oil. Bon-Neem is a blend of insecticidal soap and neem. One company, EcoSMART Technologies, offers a whole line of reduced risk products based on a combination of plant essential oils (thyme oil, 2-phenethyl propionate, rosemary). Just like traditional pesticides, these products come formulated as wettable powders, emulsifiable concentrates, dusts, etc.

Minimum-risk pesticides (as opposed to reduced risk) are a different story. They are certainly not as powerful as traditional pesticides. To qualify as a minimum-risk pesticide under 40 CFR 152.25 (g) and be exempt from pesticide regulation, a product must meet certain conditions. These conditions fall into the following two categories:

Composition. The active ingredients may only be from those listed in 40 CFR 152.25 (g). The other (inert) ingredients may be only List 4A inerts, including commonly consumed foods.

Labeling. All ingredients must be listed on the label (actives by name and percentage; inerts by name only). The product cannot bear claims to control rodent or insect pests in a way that links the pest to specific diseases (in other words, it can’t say, "controls the mosquitoes that carry West Nile virus"). The product cannot display false or misleading statements, including one that implies that the product is registered or recommended by EPA.

Unfortunately, some of these unregistered products base their efficacy information on reports and testimonials that are not published in scientific journals or other reputable outlets. In my mind, these claims and research findings would be more acceptable if published in a scientific publication which is peer-reviewed or which otherwise utilizes strict guidelines for data presentation such as Arthropod Management Tests. Much greater credibility would be garnered for all green products if tests of their efficacy were independently performed and published.

THE PUBLIC WANTS IT. As mentioned earlier, the role of green products in the pest control industry is expanding rapidly. Much of this expansion is due to public demand for so-called "poison-free" pest control products, but also to a lesser extent is due to PCOs trying to limit their liability by using less toxic compounds. I have heard of many clients telling their pest control technician something like this, "I want these ants gone, but I don’t want one drop of pesticide used in or around my house."

What do you do in a situation like that? I personally think the best thing to do is to incorporate green products into our repertoire of pest control tools and use them wherever we can. It certainly can’t hurt anything, and shows to our customers (and critics) that we are trying to be environmentally friendly. But don’t get me wrong. There are many circumstances where greens will be ineffective, even useless. There’ll always be a need for traditional, residual pesticides.

Once I was collecting ticks in a heavily infested area in northeastern Oklahoma where the ground was literally moving under my feet with ticks. It was like a horror movie. I caught more than 5,000 adult lone star ticks in less than 30 minutes! Brother, when you’re in a place like that, you don’t need the greens — you need the stuff that smokes!

The author is a medical entomologist for the Mississippi Department of Health, Jackson, Miss. He can be reached via e-mail at jgoddard@giemedia.com.