Dangling Sunflowers Caused by Sunflower Headclipping Weevil
It’s not vandals or strong winds that broke the broken stem of your sunflowers. It may be the work of the sunflower headclipping weevil (Haplorhynchites aeneus).
This ¼ inch long shiny black weevil attacks other members of the aster family including purple coneflowers, cup and compass plants. It feeds on the stems just below the developing flower or on the leaf stems. The partially severed stems remain attached dangling from the plant. The adults can often be found within the flower feeding on the pollen, mating and laying eggs.
The eggs hatch when the flower hits the ground. Here the immature stage of the weevil, called grubs, feed and spend the winter. They pupate and emerge as adults next year.
Carefully remove dangling flowers and drop them into a can of soapy water to kill adult weevils. Dispose of these and any infested flowers on the ground to reduce future infestations.
A bit more information: It is believed that only the females do the stem clipping. This energy intense behavior may discourage other flower-feeding insects from moving in to compete with the headclipping larvae.
Related
Audio
Categories
Upcoming Appearances
Oct. 27, 2021
Pruning Tips for Shrubs
Webinar
Nov. 13, 2021
Holiday Specialties at Ebert's
Ixonia, WI
Register today! Plus, watch Melinda's past webinars ON DEMAND
for a limited time.
Learn More
Book an Appearance
Enter to win a $150
Corona Tools Gift Card
