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June 3, 2003
Euonymus scale crawlers emerge and are susceptible to treatment when catalpa is in early bloom, now occurring in southern and central Illinois. The crawlers are lemon yellow in color, easily spotted on leaves. Pyrethroid and other contact insecticides, including insecticidal soap and summer spray oil, are effective.

Black vine weevil adults can be treated in southern and central Illinois and should be out near the end of the first week of June in northern Illinois. These insects feed as larvae on the roots of yew, strawberry, hemlock, and rhododendron. The adults eat notches from the leaf margins of the larval host plants, along with euonymus, clematis, and many other plants. The adults feed at night, hiding in debris below the plant during the day. Adult weevils are hard-shelled, gray, 1/4-inch-long beetles with scattered, indistinct, yellowish dots on the back. Only females are known, but they feed for 2 weeks before their ovaries mature and they can lay eggs. Control of the adults during these first 2 weeks is the most efficient way to avoid larval damage. Acephate (Orthene), bifenthrin (Talstar), and cyfluthrin (Tempo) sprayed heavily on the foliage so that it runs off under the plant are effective against the adults. Hb nematodes are effective against the larvae.

Dead anthomyiid flies are common this year. A fungus attacks these grayish, 1/4-inch flies. The fungus causes the fly to crawl to the tip of a leaf, branch, post, or other upright object, where the fly dies. Whitish hyphae soon emerge from the fly’s body, making the fly look fuzzy. Presumably, the high location allows for the better dispersal of spores from the fungus. Although these flies may be numerous and very noticeable, they are not pests.

Author: Phil Nixon


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