How to Manage Pests

Pests in Gardens and Landscapes

Sunflower stem weevil—Cylindrocopturus adspersus

Sunflower stem weevils are pests of sunflowers. Adult beetles are dark brown with light spots and about 1/8-inch long. Larvae are pale maggots.


Larvae bore in stalks and overwinter in lower stalks and crowns. Foliage yellows and wilts. Plants fall over.


Consider delaying planting; many beetles will emerge and die before laying eggs. Deeply incorporate or remove and dispose of debris. Consider planting other plants. Avoid broad-spectrum insecticides; parasites may help to control beetles.

Statewide IPM Program, Agriculture and Natural Resources, University of California
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