Alligator Weed

Alternanthera philoxeroides

An Invasive Biocontrol Plant

This plant has been documented in the Mississippi area. It is a fairly common emergent plant species in the South and can be found easily in drainage ditches and lake edges.


Alligator weed is a good example of an invasive weed that has been successfully managed through biological control programs. Take these numbers for instance: there were 97,000 problem acres of alligator weed in the US in 1963; by 1981 there were less than 1,000 problem acres. Why did this happen? It was mostly the work of the following three biocontrol insects:

1. Alligator weed flea beetle (Agasicles hygrophila)
2. Alligator weed thrips (Amynothrips andersoni)
3. Alligator weed stem borer (Vogtia malloi) shown in the video

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Written by Rob Nelson

Rob is an ecologist from the University of Hawaii. He is the co-creator and director of Untamed Science. His goal is to create videos and content that are entertaining, accurate, and educational. When he's not making science content, he races whitewater kayaks and works on Stone Age Man.

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