Purple Loosestrife (Lythrum salicaria), a native of Europe, is a hardy perennial that can reach 8 feet in height. A once popular garden plant due to its adaptability, it escaped into the wild quickly spreading into wetland areas where its impenetrable stands replace valuable wildlife habitat (unbelievably, it is still sold in garden centers). A single plant can produce up to 300,000 seeds annually that are widely dispersed and result in an estimated 475,000 acres of wetland degradation annually by this "purple plague." Loosestrife has rapidly spread along the shoreline of Oyster Pond, replacing our native cattail marshes .
Wetlands Invasives Steering Committee (WISC)
Luckily, Falmouth has many concerned volunteers working to bring both plants under control. Last summer, Dr. Richard Payne organized over 50 volunteers to map every nook and cranny in Falmouth for the presence of either species. The good news -- three stands of the rare, native phragmites were found. The bad news for us -- Oyster Pond has a large abundance of both species.After examining several control options, the WISC choose biological controls, or beetles, for purple loosestrife and manual removal and herbicide applications for phragmites as the most viable alternatives.
Beetles for Biocontrol
Dr. Payne appeared before the OPET Board in May to discuss plans to release two species of host specific loosestrife eating beetles, Galerucella calmariensis and Galerucella pusilla in the Oyster Pond area. This is the only feasible method to control loosestrife, as neither mowing, burning, herbicides, nor water level management is successful.To avoid a potential "releasing the genie in the bottle" problem, the USDA rigorously tested the beetles for potential impacts prior to approving their use in 1992. The tests included "feeding trials"- exposing the beetles to
The OPET Board voted to join the Woods Hole Oceanographic Institution and Salt Ponds Area Bird Sanctuary in donating $350 each to purchase 10,000 beetles for release this fall. The beetles will be sprinkled about in groups of 100 to 200 around the Oyster Pond and Salt Pond areas.
There will be little activity by the beetles this year as they concentrate on wintering over in stalks of loosestrife. It is when they emerge hungry next spring they really go to work. By the second season, the plants will be much reduced in size and scope. It will take 3 to 5 years to completely eradicate or at least control the loosestrife, allowing native vegetation a chance to remerge or at least compete.
Cut and Treat
Phragmites control still depends on human activity for eradication. The best method is to cut the canes down in late summer when the energy of the plant is concentrated in the blossom in preparation for seed generation. Rodeo, a glyphosate herbicide similar to Roundup, is dropped into each hollow cane, a very tedious task.! It takes several seasons for this to work.The WISC and the town Land Management Working Group chose three test sites for this method: the Margaret Doutt conservation parcel in Waquoit, a small secluded stand on the Breivogel conservation parcel and the upper parking lot at Old Silver Beach. Unfortunately, the phragmites on Trunk River and will have to wait.
Volunteers are needed to cut and remove the phragmites canes. Licensed Town employees with apply the Rodeo. Dick Payne welcomes volunteers. Contact him at 508-540-4732 or dannas@cape.com .