The Sunflower Headclipping Weevil feeds on many plants, including Sunflowers, Coneflowers, Prairie Dock and Ragweed.
Weevil damage includes dangling flower heads and stems with decapitated heads that looked like soda straws. “Headclipping” accurately describes the plant-damaging behavior of this weevil.
The shiny weevils range in color from black to copper brown. In fact, the specific epithet, aeneus, means “bronze-colored.” They measure a little over 1/4″ in length, including an exceptionally long, curved snout. As with all weevils, this beetle’s mouthparts are located at the end of their snout (rostrum).
The best method for controlling this weevil is to remove and destroy the dangling flower heads and heads that have dropped to the ground. This will prevent weevil larvae from completing their development, thus reducing the weevil population for the next season.
Insecticides are not a viable option. Insecticide labels will not support making an application to plants in full flower because of the substantial risk of killing plant pollinators.