<p>These substances represent a relatively new class of natural insecticides that show promise as an eco-friendly alternative to synthetic chemical pesticides. <br /><br />"We are exploring the potential use of natural pesticides based on plant essential oils -- commonly used in foods and beverages as flavourings," said study presenter Murray Isman of the University of British Columbia (UBC). <br /><br />These new pesticides are generally a mixture of tiny amounts of two to four different herbs diluted in water. Some kill insects outright, while others repel them. <br /><br />Over the past decade, Isman and colleagues tested many plant essential oils and found that they have a broad range of insecticidal activity against pests. <br /><br />Some herb-based commercial products now being used by farmers have already shown success in protecting organic strawberry, spinach, and tomato crops against destructive aphids and mites. <br /><br />"These products expand the limited arsenal of organic growers to combat pests. They're still only a small piece of the insecticide market, but they're growing and gaining momentum," he said. <br /><br />The natural pesticides have several advantages. Unlike conventional pesticides, these "killer spices" do not require extensive regulatory approval and are readily available. <br /><br />An additional advantage is that insects are less likely to evolve resistance -- the ability to shrug off once-effective toxins. They're also safer for farm workers, who are at high risk for pesticide exposure, he noted. <br /><br />But the new pesticides also have shortcomings. Since essential oils tend to evaporate quickly and degrade rapidly in sunlight, farmers need to apply the spice-based pesticides to crops more frequently than conventional pesticides. <br /><br />Researchers are now seeking ways of making the natural pesticides longer-lasting and more potent, he noted. <br /><br />These findings were presented at the American Chemical Society's 238th National Meeting. </p>
<p>These substances represent a relatively new class of natural insecticides that show promise as an eco-friendly alternative to synthetic chemical pesticides. <br /><br />"We are exploring the potential use of natural pesticides based on plant essential oils -- commonly used in foods and beverages as flavourings," said study presenter Murray Isman of the University of British Columbia (UBC). <br /><br />These new pesticides are generally a mixture of tiny amounts of two to four different herbs diluted in water. Some kill insects outright, while others repel them. <br /><br />Over the past decade, Isman and colleagues tested many plant essential oils and found that they have a broad range of insecticidal activity against pests. <br /><br />Some herb-based commercial products now being used by farmers have already shown success in protecting organic strawberry, spinach, and tomato crops against destructive aphids and mites. <br /><br />"These products expand the limited arsenal of organic growers to combat pests. They're still only a small piece of the insecticide market, but they're growing and gaining momentum," he said. <br /><br />The natural pesticides have several advantages. Unlike conventional pesticides, these "killer spices" do not require extensive regulatory approval and are readily available. <br /><br />An additional advantage is that insects are less likely to evolve resistance -- the ability to shrug off once-effective toxins. They're also safer for farm workers, who are at high risk for pesticide exposure, he noted. <br /><br />But the new pesticides also have shortcomings. Since essential oils tend to evaporate quickly and degrade rapidly in sunlight, farmers need to apply the spice-based pesticides to crops more frequently than conventional pesticides. <br /><br />Researchers are now seeking ways of making the natural pesticides longer-lasting and more potent, he noted. <br /><br />These findings were presented at the American Chemical Society's 238th National Meeting. </p>
