Coreopsis Beetle

Description

Coreopsis Beetle (Callligrapha californica) is a common leaf beetle, small, up to 1/4 inch in length, that occurs throughout the United States. The body is oval with black and yellow stripes and a black head. Adults and larvae both feed on plants, skeletonizing the leaves by eating the tissue between veins. Leaves can also have a ragged, chewed up appearance. Beetles will also chew on stems and can decimate a plant quickly when populations are high.

Target Crops

Coreopsis (tickseed), Dahlia, Bidens and Ragweed.

Life Cycle

The young larvae appear in spring and begin feeding on the plants. They can cause severe damage to plants due to high densities. The larvae pupate in the soil and adults emerge in early summer. Adults feed on plant material for several weeks before females lay eggs near the base of Coreopsis plants. Eggs overwinter in leaf litter and protected areas until the larvae hatch out in spring to start the cycle again.

Beneficial Insect Control

Stratiolaelaps and Dalotia are both soil predators and can help control the very young larvae and eggs in the soil. Rates for Statiolaelaps are 25/ft2 and Dalotia .1 to .5/ft2.

Insecticide Options

Use in rotation for best results. Azadiractin or neem oils act as insect growth regulators, antifeedants and ovipositional deterrents. These include Azaguard and Molt-X.

Mycoinsecticides containing entomopathogenic fungal spores. These include Botanigard, Mycotrol, NoFly, Bioceres, Velifer and PFR 97.

Oils and soaps can be very effective. Circadian Sunrise is a corn/peppermint oil that suffocates insects. M-Pede insecticidal soap and Suffoil-X are more options.

Grandevo is a broad spectrum bioinsecticde containing Chromobacterium which can suppress leaf beetles.

For a quick knockdown, use Pyganic with Pyrethrin for an organic adulticide. Surround WP is another option. This contains kaolin clay which acts as a mechanical barrier, irritant and disrupts the beetles ability to find host plants.

Cultural Control Tips

Remove plant debris in and around gardens and orchards to reduce overwintering eggs.
Monitor plants in early spring for signs of feeding. Look for adults on flowers and foliage of susceptible crops.
Use sticky traps to monitor for adults in spring.
Rotate susceptible crops in your garden.
Knock adults into a bucket of soapy water and drown them.
Encourage wild birds into your yard to feed on Coreopsis beetle.