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Ornamentals and Turf |
I'd like to make sure you are aware of Talus (buprofezin), a new insect growth regulator insecticide from Sepro. Unlike most insect growth regulators, which mimic insect hormones, this product is a chitin synthesis inhibitor. It acts against the nymphal stages of whiteflies, armored and soft scales, mealybugs, planthoppers, and leafhoppers by interfering with the insect's ability to make its chitin exoskeleton. It also suppresses oviposition of adults and reduces egg viability. It is labeled for greenhouse, landscape, and nursery uses, and also for greenhouse tomatoes. Yes, there is finally a new product for this crop. It is also labeled for poinsettias after bract coloration, although we know that North Carolina growers ALWAYS pay attention to whiteflies early in the production of the crop and do not need this option!
The April 16, 2004 issue of the North Carolina Pest News described the use of phenological indicators to predict insect activity in ornamentals (see http://ohioline.osu.edu/sc189/sc189_29.html). Since timing is so critical for chemical control of borers, a summary of some of these relationships for key boring pests is provided below. Larvae will become active 7 to 10 days after adult emergence.
A partial list of pesticides labeled for borer control for homeowners was published two years ago in the May 10, 2002 issue of the North Carolina Pest News. It seems like a good time to repeat this. Pyrethroid insecticides are available for borer protection. The following list contains a few chemicals labeled for borers that may be found on the shelves. The chemicals may be used if the site is listed on the label. This is not a guarantee of control for all pests.
A recent complaint from one of the counties in western North Carolina reminds us that boxelder bugs may be occurring. Boxelder bugs feed on the seeds of boxelder trees and to a lesser extent on the seeds of maples and ash trees. Sometimes these bugs can become abundant. However, when boxelder bugs annoy people year after year it is usually because they have a female boxelder tree in the yard or nearby. Ornamentals and Turf Insect Information Note No. 40 provides additional information on boxelder bugs. Boxelder bugs are a more frequent complaint later in the season, but it is not uncommon to receive complaints at this time of year. If desired, any insecticide should be directed onto the bugs to kill them, not onto the tree or non-infested parts of the house.
Spider mites are tiny, warm season arthropods that insert their tiny, scissor-like mouthparts into leaves and petals and cause tiny yellow spots to form as they suck out the contents of the plant cells. Hot, dry weather apparently inhibits parasitic fungi and accelerates the life cycle of the spider mites. Daylilies, roses, butterfly bushes, some euonymus and bedding plants are often infested by spider mites during the summer. Because spider mites flair up in dry weather, their control is somewhat difficult. Plants that have wilted slightly are much more susceptible to pesticide injury than turgid plants. Also, plants are much more likely to be burned if pesticides are applied during midday. Plants should be watered thoroughly before spraying them with pesticide and should be sprayed in early morning or late afternoon so that the pesticide residue is dry before the bright, noon sun hits it. For homeowners, if plants are robust enough, spraying the foliage with the garden hose will dislodge some mites.
Horticultural oils and soaps are moderately toxic to spider mites and they are relatively safe for humans. Soaps and oils have virtually no residual activity so both pesticides must be applied two or three times for complete control (about 5 days between sprays). Horticultural oils have been shown to be less harmful to beneficial predatory mites.
For commercial nurserymen, Joust also gives excellent control of spider mites and mite eggs on trees, shrubs and flowers (however it is not labeled for use in the greenhouse). Avid is labeled for spider mites outdoors except on coniferous evergreens. Floramite is another excellent miticide for mobile stages and is labeled for greenhouse, nursery, and landscape use. It is also compatible with many beneficial organisms. Hexygon is another good miticide.
Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age or disability. North Carolina State University, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.
Last modified on May 24, 2004 by Stephen J. Toth, Jr.