Michigan State University Extension
Ornamental Plants plus Version 3.0 - 00000436
11/12/99
COSMOS INSECT PROBLEMS
Aphids suck plant juices and can be controlled with
properly labeled pesticides.
Four-lined plant bug causes circular brown spots on the
leaves when it feeds. The spots can be numerous and may
be confused with a disease.
Tarnished plant bug punctures shoots and injects a poison
causing the shoot to die.
European corn borer may feed on cosmos in late summer.
The larvae feed on buds and flowers causing distortion.
The stem boring causes wilting and death of plant parts
above the point of lowest injury. Remove the dead tip by
cutting 2 inches below the wilt point.
Mites cause the leaves to be grayish.
Related information.
Pesticide Recommendations
Aphids on Ornamentals
Four-lines Plant Bug
Spider Mites
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mentioned. This information becomes public property upon
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This file was generated from data base ZZ on 01/19/00.
Data base ZZ was last revised on 11/12/99.
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