Fresh Pond Reservation

Purple Loosestrife Biocontrol Project

Purple Loosestrife, Lythrum salicaria, is an invasive wetland plant species native to Europe and Asia.  It first appeared in North America during the 19^th century, brought to this continent both in the ballast of ships and as an ornamental for gardens.  This highly invasive plant has been observed in every state in the continental US with the exception of Florida.  Purple loosestrife was first observed at Fresh Pond Reservation over 5 years ago, and  has spread to inhabit shoreline space along every waterbody on the Reservation, as well as in several of the wetland bioswales. 

Friends of Fresh Pond Reservation and the Cambridge Water Department are working cooperatively to implement a control project at Fresh Pond Reservation that will limit purple loosestrife populations and allow native species to reclaim areas currently inundated with the invasive plant. 

While several control methods have been tried at Fresh Pond Reservation, none have been completely successful at reducing the number of purple loosestrife plants or limiting their spread.  Cutting the purple loosestrife causes the plant to sprout more stocks, leading to increased flowering.  Pulling up the plant is very difficult, and if the entire plant is not removed, the remaining root system can still send out shoots.  Herbicide is not a preferable option so close to drinking water source, especially as yearly application is necessary.  Biocontrol, in the form of the Galerucella beetle, seems to be our best choice for reclaiming wetlands on the Reservation. 

Learn more about the Galerucella beetles

Fresh Pond Reservation Purple Loosestrife Biocontrol Project
Phase 1 Little Fresh Pond Release

On the western end of Fresh Pond Reservation, just north of Little Fresh Pond is a wetland that has been heavily impacted by purple loosestrife.  This area was once home to a mixture of native wetland species, but now roughly half of the wetland is dominated by purple loosestrife.  It is here that on May 31, 2007 we released roughly 5400 Galerucella beetles.  The beetles will feed, reproduce, and die off, leaving their offspring to continue the cycle.  To learn more about the release at Little Fresh Pond, click here>>

Fresh Pond Reservation Purple Loosestrife Biocontrol Project
Phase 2 Beetle Rearing

For the second phase of the Fresh Pond Reservation Purple Loosestrife Biocontrol Project, we are raising our own beetles for use in the other areas of the Reservation.  In the future, this will limit the number we will have to buy.  To learn more about beetle rearing, click here>>

Volunteer Opportunities

This summer - Volunteers can sign up to assist with field monitoring, tend to beetle nurseries, or help collect and build equipment necessary!  Please contact Hannah Wilbur, Watershed Management Assistant at fpr@cambridgema.gov or 617 349 6489.