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Three Chinese mitten crab specimens are photographed by the water outside of Copps Island Oysters in East Norwalk, Conn. Thursday, June 18, 2020. The invasive species of crab has been spotted recently in the waters of the Housatonic River. The crabs are a major problem because of their burrowing activity that can compromise the integrity of levees and waterfront construction and rapidly increase stream bank erosion.

The emerald ash borer, a small beetle that kills ash trees, is making its way down from North Texas.

Candlewood Lake Authority officials discovered a third zebra mussel on the lake's shoreline prompting it to investigate the extent of the species in the area.

Invasive jumping worms, which a Connecticut scientist says have the potential to cause widespread damage, are distinguished from native earth worms by their milky white collar.

Over the past decade, several new invasive species have appeared in Connecticut that are threatening to destroy parts of its ecosystem.

In order to combat their growth, Substitute House Bill No. 5259 was passed, which makes it illegal to transport some aquatic invasive species on a boat or trailer.

Here are the invasive species the Nutmeg State officials are concerned about: 

The emerald ash borer, a small beetle that kills ash trees, is making its way down from North Texas.

This green beetle causes destruction by feeding on ash trees.

Since it first showed up in Connecticut in 2012, they have destroyed almost all of the state’s ash trees, Robert Miller writes.

The insect is originally native to Asia and is thought to have made it to the U.S. in 2002 through a solid wood packing material, according to the Emerald Ash Borer Network.

This Sept. 20, 2013 photo provided by the USDA Forest Service shows a southern pine beetle completing metamorphosis into an adult that will attack a pine tree, at Kisatchie National Forest.

The southern pine beetle, which is infamous for overwhelming and killing healthy pine trees, was found in Wallingford in 2015 and has since been reported in more locations across the state.

It is not known how they made their way to the Nutmeg State, but the beetles originated from the Southern part of the county, according to Climate Woodlands. 

Three Chinese mitten crab specimens are photographed by the water outside of Copps Island Oysters in East Norwalk, Conn. Thursday, June 18, 2020. 

These crabs cause damage by burrowing, which can destabilize shores, destroy dams and levees, clog screens, pumps and water intake structures.

It is unknown how the crabs ended up in the Nutmeg state as they are native to the cool waters of the Pacific. A single mitten crab was first found in New Haven in 2018 and since then, they have been multiplying. 

Pictures and names of the different types of ticks, courtesy of the Connecticut Agricultural Experiment Station

The Nutmeg state is home to at least three species of invasive ticks, including the Asian longhorned tick, the Gulf Coast tick and the lone star tick.

There is a high concentration of them in the state, Dr. Goudarz Molaei told Hearst Connecticut Media in June.

“It takes maybe less than an hour for us to collect over 800 ticks," Molaei said.

Candlewood Lake Authority officials discovered a third zebra mussel on the lake's shoreline prompting it to investigate the extent of the species in the area.

Zebra mussels, which are notorious for their ability to rapidly dominate a water body, were found in Candlewood Lake in 2020.

The mussels can feed on tiny organisms that support fish populations and create entire ecosystems.

A Northern snakehead, which is an apex predator fish known for its "voracious appetite," was found in Pameacha Pond in Middletown in 2017.

While they are most common in Africa and Asia, it is not known how one found its way to Middletown.

The Department of Energy and Environmental Protection says this was the only confirmed sighting of the fish. A second one might have been caught shortly afterward, but that could have been the same fish. 

DEEP Fisheries Biologist Bruce Williams told Hearst Connecticut Media in July the department is still concerned it was not a solitary incident.

Invasive jumping worms, which a Connecticut scientist says have the potential to cause widespread damage, are distinguished from native earth worms by their milky white collar.

Jumping worms — which are also known as “crazy worms,” “crazy snake worms” and “sharks of the earth” — have been found all over Connecticut.

They can cause damage to the environment by destabilizing soil, causing nutrient leaching and erosion, increasing drought vulnerability and causing turf detachment from soil and unstable rooting, according to an alert by state scientist Gale Ridge.

“Their activity has toppled stone walls in New England,” Ridge wrote in the alert. “Many native trees and plants (including garden plants) cannot germinate or develop in this altered soil, while invasive species thrive.”

A group of adult Spotted Lannternflies on the side of the Berks County Services Building. 

Clusters of spotted lanternflies can cause heavy damage to trees, destroy fruits and hurt the agricultural economy, DEEP said.

“Many of the fruit trees grown in Connecticut, such as apples, cherries, and peaches, are also considered to be vulnerable,” DEEP said. “Even if the insect does not kill the trees, it could destroy the value of the fruit ... The impact on the agricultural industry of Connecticut could be devastating.” 

Spotted lanternflies originated in parts of Asia and made their way to the United States through a shipment of goods to Pennsylvania in 2012.

The invasive plant hydrilla — which scientists say “crowds out native vegetation, harms fisheries, sickens wildfowl, impedes recreation, and reduces property values” — has been found in the Connecticut River.

A task force was formed to investigate reports of hydrilla in the southern part of the river in 2018. In 2020, scientists with the Connecticut Agricultural Experiment Station Invasive Aquatic Plant Program said they discovered a new strain of the plant. 

Hydrilla is more commonly found in Florida and other Southern states, scientists part of the Invasive Aquatic Plant Program said.

A Spongy Moth, Lymantria dispar, perched on a dead tree.

The moths, which tend to devour plants, infested Litchfield County in 2021.

Chris Martin, state forester with the state Department of Energy and Environmental Protection, said they have affected around 40,000 acres of forests in the county. 

The moths first made their way to North America in 1866 when a lepidopterist imported them to his home in Massachusetts, but they escaped.

The black locust trees, which are known for growing tall and spindly, are native to the Appalachian woodlands.

They are harmful because they can choke out native vegetation in dry areas as well as along streams, according to the Nationl Resources Conservation of Connecticut. 

Recently some of them were slated for destruction near Stamford’s Cloonan Middle School. 

The mile-a-minute vines can grow up to 6 inches a day and can form dense mats that crowd out native species, according to the National Invasive Species Information Center.

The plant was found in Milford in 2021 and has been previously found in Greenwich in 2012. It is believed to have been in the United States since 1930, according to the National Invasive Species Information Center.

Volunteer Jevera Hennessey, of Stamford, clears Japanese Knotweed that has overgrown a portion of the Stamford Land Conservation Trust Woodsend Preserve in Stamford. 

Japanese knotweed was spotted in the Stamford Land Conservation.

The plant can grow up to 10 feet in height and can also cause physical property damage because of the way it grows underneath dirt. 

The plant is notorious for being hard to kill, being resistant to high temperatures, drought and floods, Stamford Land Conservation Trust member John Stone said in 2019.

In this July 9, 2010 file photo, UC Davis research scientist Marion Wittmann holds a handful of Asian clams removed from the bottom of the lake in 15 feet of water near South Lake Tahoe, Calif.

Asian clams were found in Candlewood Lake in 2017. 

While the Candlewood Lake Authority does not consider them as big a threat to the environment as zebra mussels, they can still deplete food resources of other wildlife, according to New York Invasive Species Information.

Cassandra Day is an award-winning multimedia journalist and resident of the North End of Middletown who has been reporting nearly every facet of the city for over two decades.

Ben Lambert covers police and public safety for the Register. A graduate of the University of Massachusetts-Amherst, he has worked on the behalf of the Valley Advocate, MassLive, The Register Citizen, and now, the New Haven Register. He spends far too much time thinking about the Boston Celtics.

I work in the Connecticut Post newsroom in Bridgeport, mainly covering breaking news as it's happening for Hearst Connecticut Media. For updates, photos and videos from the scene of breaking news events, follow me on Twitter @Tara_O'Neill_. Send breaking news tips to toneill@hearstmediact.com or by calling 203-330-6257.

Ignacio Laguarda is a reporter who covers education and more for the Stamford Advocate.