Total Landscape Care Digital Magazine
Issue link: http://read.dmtmag.com/i/85694
chemical care inability to distinguish from real and imagined impulses. Insecticides in the organophosphate and carbamate group use this mode of action. Chloro- nicotinyls, another chemical class, affect the nervous system in a different way, by blocking receptor sites. Imidacloprid uses this mode of action. Over time, using chemicals in the same class can result in insects building a resistance to the active ingredient in the insecticides, according to Pat Vittum, professor of entomology at the University of Massachusetts. "Insects can develop the ability to break down in- secticides with repeated use, making it necessary to switch to a whole new chemical class of insecticide for good control," Vittum says. So if you use bifenthrin (a pyrethroid) and then switch to cyfl uthrin (another pyrethroid), as far as the insect is concerned, you are still using the same mode of action. "If an insect develops resistance to one insecti- cide in a given chemical class, it normally automati- cally develops resistance to others in the same class (or mode of action)," Vittum says. "So knowing the mode of action is important so the turf manager can avoid its repeated use." Alternate Ending A wise management strategy is to use more than one mode of action, normally by alternating from one to another. Rotating insecticides from different chemi- cal classes is especially important on properties that require more than a single application in a season. "Avoid using the same mode of action in con- secutive applications, and avoid using the same mode of action several times in a growing season," Vittum says. Fit Turf, a Denver-based lawn care company that services 3,500 clients, evaluates insecticide resistance on a case-by-case basis. For properties that receive insect control applications only once or twice a year, rotation of insecticide isn't an issue, according to sales manager Michael Snyder. MORE where it matters most. In borders, beds and turf, Nufarm has more ways to give you what matters most to keep your business growing. MORE CONFIDENCE Use Escalade® consistent, no-surprises broadleaf weed control. 2 virtually any time, anywhere for MORE EASE Non-turf areas stay clean for months with one shot of 'stays-put' ProDeuce® . 36 TOTAL LANDSCAPE CARE / January 2012