Pest of the Month – July 2016

PEST ALERT – Diaprepes Root Weevil

Photos: University of California Cooperative Extension (See Additional Resources below)

 

beetles

Adult beetles vary in size between 3/8 to 3/4 inches long.

Distribution: The Diaprepes root weevil (Diaprepes abbreviatus) is currently not present on any Hawaiian islands. Native to Caribbean region, it was introduced into Florida in 1960s. The beetle is established in certain 
quarantine areas in Southern California (Los Angeles County, Orange County, and San Diego County – 
certain cities within each county).

Hosts: There are 270 different plants affected by the Diaprepes root weevil, including citrus, avocado, hibiscus, Indian hawthorn, holly, palms, and other 
ornamentals.

Damage: Chewing damages both leaves and roots of plants. Semi-circular areas are chewed from leaf margins. 
Grub-like larvae feed on roots, weakening or killing the plant.

frass

Telltale frass and chewing damage from the Diaprepes root weevil.

Control: Each life stage must be treated with varying pesticides except for pupae stage.
If this pest is found in Hawaii, immediately report to Hawaii Department of Agriculture at 643-PEST, or reportapest.org or bring in 
samples (in a sealed bag) to HDOA .

Additional Resources

”Have you seen this insect?: the Diaprepes root weevil”, University of California Cooperative Extension, October 2007. URL: https://www.cdfa.ca.gov/plant/factsheets/43617_HaveYouSeenThisInsect_DRW_ANR_Oct2007.pdf