INVASIVE SPECIES ALERT
Be on the lookout for these invasive species!
BLUE GREEN ALGAE
HAND PULLING WATER CHESTNUTS
Water Chestnuts are a non-native invasive species which originated from Europe, Asia and Africa. Released into the Northeast United States in the mid to late 1800s; water chestnuts are thought to have been introduced to Massachusetts first. By the 1950s the plant had made its way into the Great Lakes Basin.
Water Chestnuts (T. natans) are a non-native invasive species which originated from Europe, Asia and Africa. Released into the Northeast United States in the mid to late 1800s; water chestnuts are thought to have first been introduced in Massachusetts. By the 1950s the plant had made its way into the Great Lakes Basin.
The Water Chestnut grows in slow moving water bodies and in water depths up to 16’. The plants are annuals that can release upwards of 15-20 seeds per year and quickly multiply into a large infestation. Floating seeds will not germinate, but green to greenish brown seeds will sink to the sediment and germinate. The seeds can remain viable for up to 12 years in the sediment which results in the need for repeated annual harvest for 5-12 years to control and eradicate the population. As for biological control, parasites control the population in Europe, Asia, and Africa but a leaf beetle (Galerucella birmanica) had been studied for control in the US by Cornell from 2002-2005.
Water chestnuts can cause many problems for boaters, swimmers, and the ecosystem. The dense, thick mats of vegetation create a hazard for boats driving through. The spiny, sharp seeds can wash up on beaches where people may step on them. The mats of vegetation decrease light below water surface for other plants, thus choking out native aquatic plant species and causing a reduction in waterfowl food. At the end of the growing year, the dying water chestnuts fall to the bottom of the water body and decay. This decaying causes decreased oxygen levels for fish.
Meet this year’s crew: (L_R) Rob Rioux, crew leader; Megan Vandewarker; Maddie Rioux; and Liz Kelsey-Gossard;
HEMLOCK WOOLLY ADELGID
Hemlock Woolly Adelgid (HWA) has been in NYS since 1985. Its origin in the eastern US are likely from Japan. Hemlock Woolly Adelgid attacks eastern hemlock in NYS. The Adelgid uses long mouth parts to extract sap and nutrients from hemlock foliage. This prevents continued growth causing needles to discolor (from deep green to grayish green), then to drop prematurely. The loss of new shoots and needles causes decline and death of affected trees within 4 to 10 years.
Hemlock Woolly Adelgid is unusual in that all individuals are female with asexual reproduction. The Adelgid completes two generations a year. The winter generation produces up to 300 eggs and the spring generation produces up to 75 eggs. Hemlock Woolly Adelgid enters a period of dormancy during hot summer months. The biggest concern for the Skaneateles Lake Watershed is that hemlock provides protection of streambeds/banks from erosion. Hemlocks are also highly valued for lumber and ornamentals such as Christmas trees. And, they provide food and shelter for wildlife, especially deer. The good news is that HWA is still “A Pest We CAN Manage!” To learn more, please go to the insect section and find Hemlock Woolly Adelgid at www.nyis.info.
EMERALD ASH BORER