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Ornamentals and Turf |
Tetranychid 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 plant cells. Hot, dry weather accelerates the life cycle of the spider mites. Hollihocks, roses, butterfly bush, 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. 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.
There are a number of miticide products for commercial nurseries and greenhouses. Rotation of products is important for resistance management. Floramite controls mobile stages, while Hexygon kills eggs and sterilizes females. Akari (greenhouse only), Pylon, horticultural oil, and Ovation are also options. Avid is now labeled for spider mites outdoors except on coniferous evergreens. Nurseries and greenhouses have a long list of possible treatments in the North Carolina Agricultural Chemicals Manual. More information is contained in Ornamental and Turf Insect Information Note No. 25.
Green June beetle adults often emerge in large numbers following a period of rainy weather that softens the soil. They buzz around the yard and may seem menacing, but they are completely harmless to humans. Emergence dates vary. This year they may be waiting until after Independence Day to celebrate. We're not sure what effect so much rainfall will have on their population. Green June beetles are most common in older lawns and pastures with high organic content soils or turf which has been fertilized with manure. The adult June beetle is an attractive green and gold-colored beetle, which feeds as a minor chafer on the foliage and fruit of trees in mid summer. Sevin insecticide can be used to protect foliage and fruit also, if needed. The Insect Note White Grubs in Turf provides information on controlling beetle grubs, which is rarely necessary for the homeowner.
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 July 7, 2003 by Stephen J. Toth, Jr.
