An invasive tree species threatens to take over the banks of the Chadakoin River and, at the same time, attract an invasive species of moth that could devastate the county’s wine industry.
Members of the Jamestown City Council heard from Twan Leenders, ecological restoration manager at the Chautauqua Watershed Conservancy, on Monday regarding the ongoing cleanup of the banks of the Chadakoin River. Leenders said work has gone well so far, although the discovery of the Tree of Heaven along the Chadakoin Riverwalk is a concerning development. Worst areas include the riverfront near the fire training grounds on Harrison Street and behind the Gateway Center on Second Street.
“We are getting to the point where these core areas are starting to come together,” said Leenders. “If we don’t do something about it soon, all we’ll have left along the river is the Tree of Heaven.”
According to the state Department of Environmental Conservation, tree of heaven is the preferred host plant for the spotted lanternfly, an invasive insect found in several parts of New York City that may have severe impacts on agriculture and state forests. The tree of heaven can be identified because its plants and leaflets resemble sumac – smooth at the edges with a small notch at the base, while sumac’s leaflets have serrated edges. When touched or broken, the Tree of Heaven has a unique scent similar to burnt peanut butter.
The tree of heaven secretes a chemical into the ground, Leenders told council members, that helps it outcompete native plants for resources. Cutting one sends stress hormones through the root structure and sends out 20-40 new shoots for every sky tree that is cut. It is possible that the number of celestial tree seedlings will double next year if nothing is done.
Small sky tree plants can be dug up, but large plants like those found along the Chadakoin River require herbicide treatments at certain times of the year. Herbicides must first be used in the root system to kill the tree, then it can be felled.
“The tree of heaven is all along the river right now,” said Leenders. “It happened a long time ago, it was ornamental. It’s in Jamestown and it’s spreading. What I found while surveying is that we have three main areas where these trees have grown out of control to the point that we almost have forest land with these trees.
Leenders and his team found around 120 tall sky trees along the river and 1,200 other shoots. Work to remove them must take place until early July, Leenders said, for herbicide treatments to work as intended before the tree’s reproductive cycle is complete. Waiting until after early July to start herbicide treatments is too late because the tree of heaven will have already dropped its seeds to populate the next generation of the species. Leenders said he was confident that taking action this year could eradicate the tree of paradise from the Chadakoin River region.
Tree of Heaven also attracts the spotted lanternfly, an invasive pest that was first discovered in Pennsylvania in 2014 and has since spread to New Jersey, Delaware, Maryland, Virginia and parts of New York. It has not yet infested New York as it has in other states. The State DEC reports that the spotted lanternfly poses a significant threat to agricultural and forestry health in New York City. Adults and nymphs use their sucking mouthparts to feed on the sap of more than 70 plant species, which stresses plants, making them susceptible to disease and attack from other insects. The Spotted Lantern also excretes large amounts of “honeydew,” which attracts sooty molds which interfere with plant photosynthesis, adversely affecting plant growth and fruit yield. The annual yield of New York apples and grapes has a combined value of $358.4 million, which could be greatly affected by the spotted lanternfly.
Although native insects also secrete honeydew, the mottled lantern’s size and large populations that congregate in an area lead to large accumulations of invasive pests. In Pennsylvania, where spotted lanternfly populations are the densest, people can’t be outdoors without getting honeydew on their hair, clothes and other belongings, according to the DEC. Leenders said none had yet been found in Jamestown despite the presence of traps he and his crews had found along the river. Jamestown is an early warning area where pesticides have been applied to the trees in the tree of heaven so that if spotted the lanterns will be killed and fall into the traps if they feed on the trees near the river.
Leenders is offering to reprogram the money already approved by the council earlier this year to begin tackling the Tree of Paradise infestation while also asking to partner with the Soil and Water Conservation District of the Chautauqua County to seek new grants. Existing city spending along the Chadakoin River can cover required local matches on grants, Leenders said. Approval from the state Department of Environmental Conservation and the US Army Corps of Engineers is required before applying any herbicide due to the plant’s proximity to the Chadakoin River.
“These things are like grasshoppers,” said Leenders. “They just multiply and multiply. … The really bad part about these insects is that they have a strong preference for fruit. Once we have them here, the grape industry will be in great danger, very serious danger. Agriculture and all types of forestry will be at risk. So we have these trees here, in and of themselves, they should be removed. But the fact that we have these Mottled Lantern magnets here and have a chance to remove them before the bugs get here, I think, is worth serious consideration.