Annuals, Perennials, and Bulbs: Beetles

Problem
Insects are chewing holes in leaves and flowers. Their hard wing covers are folded across their backs, meeting in a straight line down the center of the back. They are frequently shiny and brightly colored.

Analysis
Many different species of beetles infest flowers. In the spring or summer, beetles fly to garden plants and feed on flowers, buds, and leaves. Punctured flower buds usually fail to open, and fully open flowers are often eaten. Because many beetles feed at night, only their damage may be noticed, not the insects. Female beetles lay their eggs in the soil or in the flowers in late summer or fall. The emerging larvae crawl down into the soil to spend the winter, or they mature and pass the winter in plant debris. The larvae of some beetles feed on plant roots before maturing in the fall or spring. For more information on beetles, see Beetles.

Solution
Spray infested plants with an insecticide containing carbaryl, diazinon, acephate, or malathion. Make sure your plant is listed on the product label. Note that carbaryl is deadly to bees, and should be used only on nonblooming plants to prevent bee kill.