MONTVALE, N.J. - The growing concern about the safety of chemicals, fueled by the establishment of more stringent evaluation criteria by the Food Quality Protection Act (FQPA), has resulted in many pesticides undergoing risk assessment. Under the observation of the Environmental Protection Agency (EPA), pesticides will be evaluated for any potential health risks to ensure a standard of safety is met with respect to human health.
The organophosphate (OP) class of pesticides was selected as the first group to be examined by the EPA for cumulative effects. Organophosphates are widely used in the green industry and include such popular products as chlorypyrifos (trade named Dursban®), acephate, diazinon and malathion. Until analyses are complete, many of the products are no longer available for certain uses, and Dursban and diazinon have already been hit with elimination schedules from the marketplace (see Dow Voluntarily Withdraws Dursban Uses and Phase Out Schedule For Diazinon Released). This has led the industry to investigate other insect-control options. However, already existing pesticide chemistries are providing effective alternatives to address these pest control needs.
With increasing pressure to treat insect problems in a timely manner compounded by dwindling insecticide options, lawn and landscape professionals must weigh carefully the products used for insect control. Today's insecticides must provide the broad spectrum of control needed to maintain healthy turf, while offering minimal environmental risks. Fortunately, there are chemical classes available that meet these criteria while providing acceptable levels of effective insect control.
PYRETHROIDS. The pyrethroid class of chemicals is the insecticide class of choice in many specialty markets, due to its broad spectrum of control, rapid knockdown, low use rates and good residual activity. Synthetic forms of the popular pyrethrin class (derived from the chrysanthemum flower), pyrethroids work by inhibiting the nervous system of insects.
As the pyrethroid class has evolved over generations, so has its effectiveness. Today's third-generation pyrethroids (deltamethrin, bifenthrin and cyfluthrin to name a few) are photostable, with longer residual control and increased effectiveness at very low use rates. These third-generation insecticides also offer rapid knockdown and excellent killing action.
Pyrethroids affect the insect nervous system by affecting ion permeability across the nerve membrane. Some pyrethroids exhibit a very broad-spectrum control, and because of their potency, can be applied at exceptionally low rates - as low as 0.06 lbs. active ingredient per application - among the lowest of any line of insecticides. These products have proven to be extremely active against a broad range of crawling and flying insects.
CARBAMATES. Another class of insecticides, the carbamates, has been providing broad-spectrum insect control for nearly 50 years. The 25 carbamate-class chemicals are among the most popular pesticides for home use. Carbamates disrupt the insects' central nervous system but with a lower environmental impact than organophosphates. They are generally excreted rapidly and do not accumulate in mammalian tissue.
Various carbamate products provide an exceptionally broad spectrum of insect control, while offering low potential for phytotoxicity, good residual activity and minimal potential for resistance based on years of experience. Also, many formulations are listed as moderately to slightly toxic, making them a suitable choice for organophosphate replacement.
Although alternatives for the widely popular organophosphate class of chemicals are currently available, lawn care professionals still need to evaluate their insect problems to find the right insecticide fit. The availability of organophosphate replacements such as the pyrethroid and carbamate classes is sure to help lawn and landscape professionals meet the ever-increasing demand to improve environmental standards, while providing effective insect control as well.
The author, Ken Kukorowski, is technical development manager - insecticides for the Chipco Professional Products group of Aventis Environmental Science. The Chipco Professional Products group offers a range of products for turf professionals, including DeltaGard® - a member of the pyrethroid class - and Sevin® - a carbamate product. Aventis E.S., North America, is headquartered in Montvale, N.J. For more information on Chipco products, visit www.aventischipco.com or call 800/438-5837.