By Barbara Walvoord
On Thursday, June 2, 2016, in a celebration here at Lathrop, 1,000 beetles will be set loose into our wetlands, hired to do a very specific job–eat our invasive purple loosestrife, which creates an ecological wasteland by choking out the native plants that provide food, nesting, and shelter for our native insects, turtles, salamanders, and birds. In this photo, purple loosestrife waves threatening arms over native boneset.
Our beetles, originally from Asia, will have been bred and shipped to us from a New Jersey facility, accompanied by paperwork from several agencies, completed by Adele Dowell on behalf of the Land Conservation Committee. Adele is now a licensed beetle-importer.
Picky, picky eaters, like most insects, these galerucella beetles have been extensively tested, to be sure that “Give me loosestrife or give me death” is their unchanging motto.
Once placed on our purple loosestrife, the lady beetles will stuff themselves with leaves for a few days, and then will each lay up to 500 eggs in a number of clusters on the stems and leaves of the plants. The larvae emerge in 7-10 days and begin feeding on leaves and shoots, after which they burrow into the leaf litter at the plant’s base to pupate–to change from a larva into a beetle. Three weeks later, when they emerge from this stage, their shells harden in a few days, and they continue to munch on leaves and shoots until they mature, mate, lay more eggs, and so on. Meanwhile, their parents fly or float to nearby purple loosestrife plants and begin the cycle all over again. When winter comes, every beetle still standing hunkers down in the leaf litter below the plants.
The beetles won’t totally eliminate the purple loosestrife, but will weaken the plants so that our native cattails and wetland flowers can compete.