MAM and the Weevil

One of the invasive plants you can find in the northeast is the mile-a-minute vine (Persicaria perfoliata). It is an annual vine in the buckwheat family that can grow as much as six inches a day and can reach heights of more than 25 feet! It invades open and disturbed areas and can easily climb trees and smother all vegetation on the ground. It has triangular leaves and barbed stems. This plant was accidentally introduced into Pennsylvania in the 1930’s.  

Here at Lasdon Park we have begun biocontrol of this vine. In June we released the weevil (Rhinoncomimus latipes) in two areas of the garden. This small black insect is host specific to the mile-a-minute (MAM) weed. The weevils feed on the leaves as both adults and juveniles. It lays its eggs on the leaves and stems. The larvae work their into the stems and stay there until fully grown. They drop to the ground to pupate. When the adults emerge, they begin to feed on the leaves, mate and lay eggs. The damage looks like small holes in the leaves. Photosynthesis is reduced and the vine begins to fail. This biological control was first approved in 2004 for MAM control.

Of course, the gardeners also spend time pulling down these vines wherever they are growing, collecting them before they go to seed. And the vines never go in the compost pile!