Finding the right fit
As new insecticide chemistries are developed, a trend toward target specificity is being realized. More than ever, you need a thorough knowledge of your quarry and your available tools.
Recent changes in regulations and the availability of new pesticides may change the way we do business. The loss of old products is being offset by the introduction of newer products. These new products can be quite effective when used properly, but they require a new perspective for proper use and timing of treatments.
Changes in our industry have been quite dramatic over the past 20 years. Corporate mergers, new markets, pests, products and regulations are just a few. Pesticide use in the urban environment, increased demand for near-perfect landscapes and increasing regulations, including the Food Quality Protection Act (FQPA), will continue to drive change. It is inevitable and, in an industry such as ours, we must constantly be receptive to change.
Change is in the wind Less than a year ago we experienced change that was implemented through the FQPA. Limitations were placed on the use of Dursban and other chlorpyrifos products, and more recently, diazinon. The state of New York recently enacted legislation that allows communities to require a 48-hour prior notification to residences within 150 feet of a pesticide application. Existing stocks of isofenphos will soon be depleted and bendiocarb will also no longer be available.
The question one might ask is whether or not there are any good changes. The answer to this question is a resounding "yes." Obviously, cultivars and plant material are much improved compared to a few decades ago. And we have seen significant gains in the durability and hardiness of many new turf varieties. However, customer expectations and demands force us to push these new cultivars to their limits.
New advantages In the past few years, we have seen some major changes in the types of pest-management tools available. Some of the improvements have come through plant resistance, but we also have seen a major shift in the product types. In the area of insecticides, the long-running organophosphate and carbamate products have been joined by pyrethroids. More recently, compounds such as the nicotinoids and phenylpyrazoles have been added to the arsenal. For a variety of reasons, including improved efficacy as well as regulatory restrictions, some of these new products are replacing some of the old standards.
The new compounds may be a good fit for your landscape maintenance needs. Their toxicities to non-target organisms may be less than the older compounds, and many of them have lower use rates. These new products help us respond positively to concerns over pesticide use. New regulations such as the FQPA continue to impact the older products we use in landscape maintenance, and the new products offer excellent alternatives.
New challenges Have the new products made our lives easier with the challenges of pest management? The answer is both yes and no. Yes, these new products offer you numerous benefits, and they are effective. But at the same time, the new chemistries provide more challenges in certain situations. Gone are the days of broad-spectrum, long-residual insecticides. Today's newer products are target-specific. This isn't necessarily bad. However, we have become accustomed to products that offer a reasonable level of control for a broad range of pests. We have also become accustomed to curative insecticide treatments.
Products such as imidacloprid (Bayer's Merit and other brands) give us a glimpse into the future of grub insecticides in turfgrass. While most products generally work best when directed towards smaller grubs early in their development, imidacloprid took this a step further. It works best when applied during egg laying or early egg hatch. In effect, it works best when applied preventively.
The subsequent marketing of halofenozide (Rohmid's Mach 2) added another product that demonstrated advantages from an environmental perspective. In addition, the soon-to-be released thiamethoxam (Syngenta's Meridian) is another product with lower toxicity than many of the older chemistries. Other products, such as fipronil (Chipco Choice), provide mole cricket control at remarkably low rates.
Characteristics of new products New chemistries tend to have a narrow control spectra, specific timing and low application rates. These attributes make them a good fit for IPM where individual targets are identified.
- Narrower spectrum. As a general rule, newer insecticides are not as broad-spectrum as their predecessors. For example, Imidacloprid does not control turf caterpillars, and halofenozide is not effective against mole crickets. They are, however, quite effective against the pest species for which they are registered. Traditional broad-spectrum chemistries have provided us the benefit of targeting multiple insects from a single application. However, new chemistries applied to combat a specific pest or developmental stage have less effect on other pests and non-target organisms.
This narrow spectra may limit the range of control, which could result in outbreaks of other pests that were previously controlled by broad-spectrum chemistries. This aspect requires us to continually monitor pest levels.
- Specific timing. The second point is that the new chemistries may be more specific in the timing of application. You may consider a product that is used in a preventive manner as being counter to an IPM approach. However, the characteristics of these newer products do fit into an IPM context. A preventative application - in an area with a known history of infestation - can replace a curative treatment with higher rates and less target specificity.
By developing and using an IPM program, we seek to reduce off-target effects. The narrower spectrum of many of the newer insecticides helps us meet that goal. Specific timing of application may also limit off-target exposure by targeting specific developmental stages.
Making the new chemistries fit IPM. - Pest ID is the key. Because many of these new products have narrower spectrums of control, you must properly identify the pest. This goes beyond just knowing the difference between a white grub and an armyworm. Even the species of white grub can be important because their developmental stages may differ.
- Learn the life cycles of your pests. You must acquire a good knowledge of pest biology to make IPM work. To make certain products work, you need accurate application timing. By understanding life cycles, you can determine when to apply. This will also help identification efforts.
- Monitor pests. To implement these new chemistries into IPM, you need a good monitoring program. By monitoring, you can determine the potential for a pest problem and develop a clear picture of pest development. Without monitoring, you will have no basis for application timing.
- Monitor applications. Because some of the newer products are applied at much lower rates, more than ever, you need to calibrate equipment accurately. Also, proper application accuracy has become even more important. A small error in calibration or application can be the difference between success and failure.
You will only have a handful of serious pests to consider in most turfgrass settings. Therefore, you don't need to understand an entire book of insect information. Selectively choose those pests of greatest importance in your area. Develop a pest notebook that provides the necessary information you need to know about each potential pest. Obtain information from local universities, conferences, extension organizations and workshops. Keep pertinent information close at hand. Building a solid knowledge base of your pests, whether they be weeds, diseases, or insects, is critical to success. By doing so, you'll be able to obtain great success with the new products while enjoying the benefits they provide.
New products offer the advantages of lower rates, reduced non-target effects, lower mammalian toxicities and new formulations. As we look even further in the future, I expect that we will see even more such products that will require extra vigilance to use. However, none of the characteristics of newer insecticides should make them any more challenging to use if we do our homework on our pests and use them appropriately.
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