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Alligatorweed Flea Beetle

Alligatorweed Flea Beetles Hard at Work in Port St. Lucie, FL

Alligatorweed (Alternanthera philoxeroides) is another invasive aquatic weed found in Florida.  It originated in South America and has become a ubiquitous noxious weed in ponds throughout St. Lucie County and the Florida Treasure Coast. Fortunately, a biological control agent, the Alligatorweed Flea Beetle (Agasicles hygrophila), has been released in Florida.

Invasive Alligatorweed

Invasive alligatorweed showing damage from biological control agents. Photo credits: K. Gioeli

In April 2021, Extension received a request for assistance with alligatorweed management in stormwater ponds in Port St. Lucie.  Knowing the alligatorweed flea beetle was likely there, I made a site visit with the assistance of Dr. Carey Minteer, UF/IFAS researcher who specializes in biological control of invasive weeds.  As expected, we confirmed that alligatorweed flea beetles were present and actively feeding on alligatorweed.  That’s good news!

Alligatorweed Flea Beetle

Adult alligatorweed flea beetle. Photo credits: K. Gioeli

Extension Agent Ken Gioeli

Extension Agent Ken Gioeli examines invasive alligatorweed for evidence of biological control. Photo credits: C. Minteer

Additional Links
UF/IFAS Indian River Research & Education Center – Hayslip Control Research and Containment Laboratory

UF/IFAS Assessment – Alligatorweed

UF Featured Creatures – Alligatorweed Flea Beetle