Horticulture
Department
PACIFIC NORTHWEST NURSERY IPM
Insects
hidden treasure
Photo: Rosetta
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PACIFIC NORTHWEST NURSERY IPM Insects
hidden treasure |
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alder
flea beetle |
Cypress tip moth Cypress tip moth, Argyresthia cupressella, is also known as cypress tip miner or arborvitae leafminer. This insect can mine the foliage of arborvitae, cypress, juniper, and redwood. The adult is a small gray, narrow-bodied moth which lays its eggs on the tips of new growth in the spring. The eggs hatch and burrow into and mine the branch tips. They remain there, feeding, through the winter until early spring when the greenish larvae emerge from their tunnels to spin white, silken cocoons in which they pupate between the branches. They have been found emerging and spinning cocoons in mid-April during 2004. The literature reports that adult moths emerge in Oregon from early May until late June with a peak in late May and early June. There is one generation a year. Damage: The larval feeding causes the arborvitae tips to turn brown in the late winter and spring, later defoliating. Feeding damage will not kill the plants but can make them unsightly and unmarketable. Management: Chemical control may be warranted when large populations of miners are present. Applying a broad-spectrum, persistent insecticide to protect the new growth is timed to adult moth activity. When cocoons appear in the spring, foliage can be shaken to assess presence of the tiny moths. The PNW Insect Management Handbook lists the following chemicals for control of this pest. 1. abamectin 2. acephate. A legal pesticide use not found on the pesticide label and not recommended by University of Idaho personnel. 3. bifenthrin 4. chlorpyrifos. Retail sale of chlorpyrifos (Dursban) for residential use was stopped as of 12/31/01. 5. cyfluthrin 6. imidacloprid 7. lambda-cyhalothrin
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| Website editor: Robin Rosetta |
