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.

Tags

sunflower weevil pests grubs purple-coneflower

Related

Article

Fertilizer and Weed Control

Article

Lack of Flowers on Nasturtium

Article

Cannas Rotted in Storage

Article

Black Spots on Pears

Article

Getting Rid of Crown Vetch

Article

Spots on Leaves of Philodendron

Article

Drooping Grape Ivy

Article

Bird of Paradise Has Never Bloomed

Article

Mushrooms Growing Where Tree Was Removed

Article

Rose Buds Turned Brown and Never Opened

• « Previous
• 1
• 2
• ...
• 35
• 36
• 37
• 38
• 39
• 40
• 41
• ...
• 44
• 45
• Next »