Q: I have been doing a lot of driving (for my business) around Berkshire County and have noticed far less purple loosestrife blossoming than in past years. Do you think it is the drought? What is your idea?
— Randy, Pittsfield
A: I do not think it is the drought, because we had plenty of rain last year and I also noticed fewer plants then. Actually, far fewer than in the past. My guess is it, among other possible reasons, is the Galerucella beetle, released widespread a number of years ago to combat the invasion of this attractive, if not beautiful, a flower that became an invasive "weed" aggressively spreading like a plague until recently.
Purple loosestrife, known to botanists as Lythrum salicaria, arrived in North America in the 1830s. It was a colorful herb planted widely by settlers for their flower gardens. To some extent, it was once a popular European folk remedy for diarrhea and dysentery. It escaped and quickly spread to wetlands, roadside ditches, and along canals, lakeshores and even in fields. Purple loosestrife also invades drier locations.
The reason for its expanding so widely is a single plant can produce an alarming million or more tiny seeds. It also spreads by roots and quickly became a perennial monoculture, outgrowing native plants. We might look at it somewhat differently if it did not reduce food and nesting sites for a wide assortment of native wildlife while competing with natives.
I sent an inquiry to Marion E. Larson, chief of Information and Education at the Mass. Division of Fisheries & Wildlife, whose response was: "Based on information from some of our staff, the introduction of the Galerucella beetle in different parts of the state over time has made a positive impact — meaning there has been a significant reduction in the proliferation of this invasive exotic plant. Beetles were introduced in various parts of the state (I know on Bolton Flats WMA near where I live about 15 years ago.) What staff who are dealing with invasive plant control are saying is that the situation has vastly improved in the past 20 years — such that we can turn attention to other invasive plant management dilemmas. Now, the beetles are not fully eradicating the plants — once plant numbers are low, so go the beetle populations. As far as our staff knows, there haven't been any beetle introductions in the last 5 to 10 years, as it appears the beetles have been able to expand to various parts of the state. There is a certain amount of cyclical timing going on in local areas, but overall, the beetle introduction as a biological control has been successful. Apparently, there have not been any negative ecological effects of this beetle introduction, which is always a concern and usually the case when a new critter or plant is involved."
Some gardeners admire this plant and a suggested alternative ornamental that is similar in color and nearly same bloom season is Blazing Star (Liatris spicata), which is available in the nursery trade and is not invasive.
Exotic invasive species (plants or animals) are the second most significant threat to both plant and wildlife species — first is obviously habitat loss. Encouraging people to "grow native" is a good thing.
This is a great opportunity to note there is a list of prohibited Invasive Plants (67, I think), which prohibit the sale of these plants in the state promulgated by the Department of Agricultural Resources. The list was developed by the Mass. Invasive Plant Advisory Group, consisting of various state environmental agencies (MassWildlife, DAR, DCR), nurseries and nonprofit plant-related entities like Native Plant (formerly New England Wild Flower Society). Visit www.mass.gov/massachusetts-prohibited-plant-list.
I also asked James Straub of the Lakes and Ponds Program for Massachusetts Department of Conservation and Recreation (DCR), who responded: "We have seen a great reduction across the state. There is still small patches, but not like it used to be. Scientifically, I cannot give you a reason. Observationally, I think it is due to the large release of Galerucella beetle." For more information, visit www.northeastipm.org/about-us/publications/ipm-insights/beetles-v-purple-loosestrife.
Many of the plants I see are damaged, stunted and not doing well.
I thought you might be interested in this article, either to pass on to your NatureWatch readers or simply for your own information. If you search "Seeds from China" there are lots of articles. The consensus seems to be, "Don't plant them." See www.usatoday.com/story/news/nation/2020/07/28/usda-advice-plant-unsolicited-seeds-china/5525129002/
— Liz, Great Barrington