Our Approach to Purple Loosestrife Remediation is Evolving

Galerucella!!

That word means little to most of us unless one is a botanist or entomologist. However, you will be seeing thousands of these little critters on the river this summer if you look closely at Purple Loosestrife plants (PLS). I have been reporting about your Foundation's work to control PLS for the last 5 years. That work has involved over a dozen volunteers and Huron Pines staff spending 2 days a year in a blitz to snip, pull, and kill as many plants as possible on the North Branch from 612 to the confluence with the Main Stream

I'm happy to report that for the foreseeable future we will not be eradicating PLS in this manner. Although we will still want to clip blossoms and dispose of them properly during August and early September, we will not be conducting the Blitz as in past summers. The reason for this change is because we have found that in other areas of heavy concentrations of PLS it can be controlled and greatly reduced in numbers of plants by introducing a beetle named (you guessed it) Galerucella.

This beetle has been introduced on the AuSable River with success as well as other areas throughout the US to control and eliminate heavy concentrations of PLS. The beetles are not indigenous to the US nor is PLS. However, the beetles have been used for many years in the US with no negative effects. Their diet is almost exclusively the leaves of the PLS plant, eliminating photosynthesis and resulting in the plant dying. Hopefully we will see results this year but it may take 2 or 3 years of placing the beetles to have best results.

PLS plants with 300-400 (adults, larvae, pupae, and eggs) will be placed in the soil on islands in late June or early July. We have identified several islands that continue to have concentrations of PLS and those islands will be a priority for placement of the beetles this summer.

During the past Blitzes, Huron Pines used an herbicide upon landowner permission to kill PLS. I'm pleased to report that herbicides will not be used as long as the beetles are successful in controlling PLS. And in fact, herbicides would negate the effectiveness of the beetles and most likely result in their death. Pulling the plants out of the ground will also reduce the effectiveness of the beetle as they need the leaves of PLS to sustain them. As the number of plants are reduced the beetles leapfrog to other areas of the river to find more PLS.

I hope this explanation of our evolvement in controlling PLS provides a thorough understanding of the Foundation's efforts and we hope that if you are asked to grant permission to place the beetles on your property, you will allow us to do so.

Bill Anderson