Monday, August 3, 2009

Week of August 3, 2009

Updated 8/5/09

Mid-Atlantic Invasive Plant Conference - August 11 & 12

Please note that the Mid-Atlantic Invasive Plant Conference will be held on August 11 and 12 at the University of Pittsburgh at Johnstown. To find out more, visit the Calendar of Upcoming Invasive Species Events page on NYIS.INFO.


NJ fingers mitten crab, fellow invaders

mitten_crabAuthorities have issued an all-points bulletin for a murky figure, but they're not seeking a criminal.

Instead, be on the lookout for . . . well, let's quote the recent alert: "Public asked to report invasive mitten crabs."

Mitten crabs?

Ouch. That gives new meaning to "one for the thumb."

In fact, Chinese mitten crabs -- although native to Asia -- have surfaced recently in New Jersey waters, including the Delaware and Barnegat bays, state officials announced Friday.

And they're not our only foreign invaders. Authorities raised a similar alarm in June when a flathead catfish -- a "voracious predator"' normally found west of the Appalachians -- turned up in the Delaware River.

And then there's South Jersey's own strange specimen -- the Asian swamp eel, also known as the Gibbsboro gender-bender.

That's right. It's "Gills Gone Wild."

[...] If you catch a mitten crab, they say, don't throw it back alive.

Friday's alert encourages crabbers to take a close-up photo of their catch and to record key details for research scientists. These include the crustacean's sex, which -- if the crab's still alive -- should probably be determined with great care.

Read the full story at link.


Online field guide to aquatic plants

Alabama has an online field guide to aquatic plants, including invasives, at link.


Munching on Garlic Mustard

A New Weevil in the Works

Garlic and mustard are common ingredients that can be found in American households. But garlic mustard? Well, that’s a different story.

Garlic mustard, Alliaria petiolata, is considered one of the most problematic invaders of temperate forests in North America. According to legend, it was brought here from Europe in the 1860s as a culinary herb, but unfortunately, it doesn’t taste very good. Since then, garlic mustard has spread to 34 U.S. states and 4 Canadian provinces.

“Garlic mustard is an invasive plant that gets a lot of attention,” says ecologist Adam Davis, who has been studying the weed for years. “It’s very noticeable and hard to eradicate because of its seed bank.” [...]

A Model Solution

To better understand garlic mustard and find a suitable biocontrol, Davis—in collaboration with colleagues at Michigan State University, Cornell University, the University of Illinois, and the Centre for Agricultural Biosciences International (CABI) in Switzerland—created a computer model that simulates the weed’s life cycle.

“In part, we wanted to answer ecologists’ criticisms that biocontrol can potentially cause as many problems as it solves because of unintended consequences,” says Davis. “We were looking for a way to choose agents that are most likely to succeed while reducing their potential for harm to native plants and environments. Ideally, we want to try to release only one organism, if possible.”

Through this model, Davis was able to predict the type and severity of damage that would be needed to reduce garlic mustard’s population growth rates. Davis performed an analysis using computer code that enabled him to change one variable at a time while keeping all the others constant, allowing him to probe the life cycle for the plant’s weak point. He found that in order to make an impact, a biocontrol agent has to reduce garlic mustard’s survival in the rosette stage and its ability to reproduce in the adult stage.

Well before Davis created the life-cycle model, CABI scientists began looking for and testing potential biocontrol agents to tackle garlic mustard. They collected data on the amount of damage each insect could inflict on the garlic mustard population. From a list of more than 70 natural enemies found to be feeding on garlic mustard in Europe, four Ceutorhynchus weevils were selected as the most promising control agents.

Combining the feeding information collected by CABI scientists and the demographic information of garlic mustard in North America, Davis used the computerized life-cycle model to assess each weevil’s ability to inflict damage on the weed and inhibit its growth. One weevil, C. scrobicollis, came out on top.

High Hopes for Little Insect

weevilThe tiny C. scrobicollis has a life cycle of 1 year and produces one batch of offspring per lifetime. Itlays its eggs on garlic mustard’s leaf stems in the fall. When the eggs hatch in the spring, the larvae feed on the weed’s root crown, the area from which the rosette’s leaves grow and where nutrients are stored.

By feeding on the root crown, C. scrobicollis stops the flow of nutrients and water from the roots to the rest of the plant. It also damages the meristem, the area of the plant where new growth takes place. As a result, garlic mustard produces fewer seeds or, in areas with high weevil populations, dies prematurely in early spring without producing any seeds.

C. scrobicollis also appears to be monophagous, meaning it eats just one thing: garlic mustard. That means scientists won’t have to worry about any unintended consequences when using this insect as a biocontrol agent.

During preliminary testing, CABI scientists believed C. scrobicollis was the best candidate to control garlic mustard. Putting the weevil’s feeding data through Davis’s life-cycle model confirmed their beliefs and created a stronger case for the permit process.

“The model gave teeth to the permit application to release this weevil in the United States,” says Davis. “It provided a peek into the future as to the impact the weevil could have on the garlic mustard population here.”

C. scrobicollis is currently in quarantine at the University of Minnesota. If all goes well, this beneficial weevil may soon be roaming North America to find a nice garlic mustard meal.—By Stephanie Yao, Agricultural Research Service Information Staff.

Read the full story at link.

Ceutorhynchus scrobicollis photo by H. Hinz and E. Gerber.


Maine needs boaters in battle against unwelcome invaders

GAIL RICE/Maine Outdoor Journal

In August 2008, a visitor to Salmon Lake in Belgrade noticed some suspicious plants near the public boat landing at Kozy Cove. The visitor, a fisheries biologist from Tennessee who understood the threat that invasive aquatic plants pose to Maine's lakes and ponds, wasted no time notifying the proper authorities.

The plant was identified as Eurasian water milfoil, and quick action by state agencies and volunteers to remove it and ensure it would not spread means that the prognosis for Salmon Lake, also known as Ellis Pond, is encouraging.

Eurasian water milfoil is considered to be one of the most aggressive invasive aquatic plants in North America. It is believed to be rare in Maine, having been detected in only two bodies of water so far (the other being Pleasant Hill Pond in Scarborough). [...]

At the end of 2008, invasive aquatic plants had been found in 30 Maine lakes and ponds, out of 374 that had been screened since 2001.

Boaters can – and should – play a key role to prevent further infestations of such plants on Maine's inland waterways. They're among the most likely to spread the infestation to more lakes and ponds by transporting plant fragments on their boats, motors, trailers and other equipment. But an alert boater can help by knowing what plants to look for and what to do if they're found.

"If we can be aware and practice good habits when we launch and haul boats, we can make a real difference and keep invasive plants and organisms from getting into Maine lakes," says Roberta Hill, program director for the Maine Center for Invasive Aquatic Plants, part of the Volunteer Lake Monitoring Program.

The fight against invasive aquatic plants in Maine has three major elements: prevention, early detection and rapid response. The case in Belgrade illustrates the importance of the latter two elements.

But where boaters can help the most is with the first line of defense – prevention – which Hill describes as "the best bang for the buck" when it comes to stopping the spread.

The center has been working since the late 1990s to educate the boating public about what these plants look like, how they can harm Maine lakes and ponds, and what boaters can do to stop them from spreading. The battle kicked into high gear in 2002, when the state launched its Courtesy Boat Inspection Program, funded through the sale of lake and river protection stickers. All registered boats operated on inland waters must have a sticker.

The VLMP has trained hundreds of volunteers and state agency personnel on plant identification. These "citizen scientists" have become a familiar sight at boat ramps, where they ask questions and invite boaters to help inspect their watercraft and gear.

The volunteers hope boaters will get into the habit of self-inspecting when they launch or haul their boats.

Specifically, boaters on inland waters should inspect their craft and equipment thoroughly before every launch and after every haul-out. This includes not just the boat, trailer and motor, but also the anchor lines, fishing and dive gear, live wells, and even floating toys and duck decoys. If you find something, remove it, carry it to a location well away from the shoreline, and bury it.

"Anything that goes into one body of water, comes out, then goes into another lake or pond, is a potential vector," says Hill. She adds that the tiniest traces of invasive plant and animal species can be virtually invisible to the naked eye, so washing your boat bottom and letting it dry out for a few days before launching in other waters is an even better idea. [...]

Read the full story at link.


Mile-a-minute, purple loosestrife among weeds wreaking havoc in Massachusetts

By Jessica Fargen/

mile-a-minuteMassachusetts wildlife lovers and protectors are mobilizing this summer to battle invasive weeds and plants that are choking out endangered flowers, threatening native birds and disrupting ecosystems.

“It’s affecting our wetlands in a number of ways,” said Carly Rocklen, outreach director and restoration manager for Neponset River Watershed Association, which has a five-year plan to reduce purple loosestrife, a beautiful but damaging flowering weed. “There are some marsh birds that won’t nest in purple loosestrife. It alters soil and water chemistry.”

Last year, the association released 80,000-plus galerucella beetles in the Milton and Canton area to battle the weed.

Georgeann Keer, project manager in the division of ecological restoration at the state Department of Fish and Game, said purple loosestrife is well-established in Massachusetts.

On the Boston Harbor Islands, ecologists are waging a battle with Oriental bittersweet, a climbing vine with pretty red fruit that smothers native vegetation and can grow out of control. The vine has been found across the state and on Harbor Islands including Bumpkin Island.

“It’s one of the worst invaders currently affecting biodiversity,” said Marc Albert, stewardship program manager for the Boston Harbor Islands National Park area. “It’s pretty much everywhere.”

Albert said staff and volunteers are needed to keep the vine in check.

Albert also is keeping an eye on a similar invasive weed called kudzu, which has ravaged forests in the South and has been found on Peddocks Island. Albert said the small patch of kudzu on Peddocks Island has been reduced in recent years with the use of a mild herbicide and monitoring.

“It’s referred to as the scourge of the South because of its capacity to take over whole forest patches,” he said.

Another invasive weed, the mile-a-minute vine, is so established there’s little hope of eradicating it.

Mile-a-minute, which can grow up to 6 inches a day, has taken over 100 acres in Blue Hills Reservation, said Alexandra Echandi, forestry assistant at in the Department of Conservation and Recreation’s southern region. The vine can grow up to 30 feet on trees.

“It pretty much takes over the natural environment, not letting anything grow - that includes birds, butterflies and turtle habitats,” Echandi said.

Fighting the vine takes staff and dedicated volunteers who must yank the weeds out of the ground to keep the plants in check, she said. Echandi recently applied for a permit to unleash weevils, a type of bug that can destroy mile-a-minute. But Echandi said there is little hope that the vine will be permanently eliminated.

Read the full story at link.

Photo by Stuart Cahill. Alexandra Echandi, a forestry assistant for the Boston Department of Conservation and Recreation, battles an infestation of mile-a-minute weed.


Emerald ash borer plagues tree life in PA

By Connie Mertz
For The Daily Item

There is a silent killer threatening to decimate ash trees across North America. So far, more than 25 million ash trees have succumbed to the deadly impact of a little beetle, known as the emerald ash borer.

"It was brought over from Asia in shipping crates and first discovered in Michigan in 2002," explained Weston Campbell, a summer intern attending Delaware Valley College who is working with Penn State Extension in Montour County.

Naturally spreading on an average of one-half mile a year, it has already reached portions of Pennsylvania.

The explanation of how it arrived in Pennsylvania so soon is a simple explained. "It has spread by satellite colonies. This is when something is moved," he elaborated. "In this case, it is through nursery stock and firewood."

Currently the Pennsylvania Department of Agriculture has quarantined Allegheny, Beaver, Butler, Lawrence, Mercer and Mifflin counties, and most recently Armstrong and Washington counties. The quarantine makes it unlawful to transport ash trees of any size, including their branches and limbs. [...]

To keep tabs on the spread of the invasive insect in Pennsylvania, purple panel sticky traps have been placed in ashes at various locations. These traps contain a blend of oils that are said to mimic chemicals emitted by stressed ash trees.

"The purple panel traps will not bring emerald ash borer into a noninfested site," said Greg Hoover, ornamental extension entomologist at Penn State University. "These traps help us determine if the pest is already there." [...]

Read the full story at link.


Emerald Ash Borer: Recommendations for Homeowner and Woodland Owner Action

Developed by: Peter Smallidge1, Holly Menninger1, Mark Whitmore1, and Charles O’Neill2. 1Cornell University Cooperative Extension, Department of Natural Resources, Ithaca, NY. 2NY Sea Grant, Cornell University, Rice Hall, Ithaca, NY.

The first occurrence of emerald ash borer (EAB, Agrilus planipennis Fairmaire) in New York State was confirmed by USDA APHIS on June 17, 2009 in Randolph, NY (Cattaraugus County). An invasive beetle introduced from eastern Asia, EAB kills all species of ash trees native to North America, and has the potential to cause severe economic and ecological damage. First detected near Detroit in 2002 it has now spread to 13 states and two Canadian provinces. Ash mortality is 100% near Detroit and is widespread in all the affected areas.


Milfoil, an invasive threat to U.S. waterbodies

Eurasian water milfoil is a fragile looking flora that was once a familiar plant to find in fresh water aquariums.

Even so, it did not stay there. Now it is believed to be an invasive species that threatens North American fresh water streams, rivers, pools and lakes.

In its native Eurasian environment it is a relatively harmless plant (but still a bit of a pest) but here, out of its normal waters, it takes over and destroys ecosystems, clogs water intakes and power plants, and makes them unsuitable for recreational purposes.

Read the full story and watch a video at link.


Weigh In On Federal Strategies for Plant Pests

USDA-APHIS has been tapped to implement the Plant Pest and Disease Management and Disaster Prevention section of the 2008 Farm Bill which is authorized at 12 to 50 million dollars per year through fiscal year 2013. APHIS intends to engage stakeholders in designing "a risk-based approach to disburse funds" and implement the bill's provisions.

To date, the APHIS plan identifies six strategies to coordinate and fund:

- Enhance plant pest/disease analysis and survey
- Target domestic inspection activities at vulnerable points in the safeguarding continuum
- Enhance and strengthen pest identification and technology
- Safeguard nursery production
- Conduct outreach and education to increase public understanding, acceptance, and support of plant pest and disease eradication and control efforts
- Enhance mitigation capabilities

More information about the program can be found on the USDA-APHIS Plant Health website. The program's site also enables anyone to sign up to receive notices about related documents and events and also to offer comments.


Weed Population Monitoring and Prioritizing for Management

News from the Center for Invasive Plant Management

Three publications that discuss the value of weed population monitoring and using a
decision support framework for prioritizing management are summarized.

Non-indigenous species management using a population prioritization
framework by Lisa J. Rew, Erik A. Lehnhoff, and Bruce D. Maxwell. Canadian Journal of Plant Science. V87: 1029-1036.

Quantifying Invasiveness of Plants: A Test Case with Yellow Toadflax
(Linaria vulgaris) by Erik A. Lehnhoff, Lisa J. Rew, Bruce D. Maxwell, and Mark L. Taper. Invasive Plant Science and Management. V1: 319-325.

The Rationale for Monitoring Invasive Plant Populations as a Crucial Step for
Management by Bruce D. Maxwell, Erik Lehnhoff, and Lisa J. Rew. Invasive Plant Science and Management. V2: 1-9.

Read the summaries at link.


Northeastern Weed Science Society Sponsors Training

The Northeastern Weed Science Society is sponsoring a Noxious and Invasive Weed Management Short Course for public and private land managers. The four-day course will be held in September in Pennsylvania. View website.


Report Compares Relocatable Commercial Vehicle Washing Systems

This report from the USDA Forest Service compares a range of vehicle washing systems with respect to efficacy, economics, waste containment, waste disposal, and the viability of any propagules that were collected in the cleaning process. View report.


Of bats and ash trees

by Brian Mann, The In Box, North Country Public Radio

Climate change is a big deal. Behind the micro narratives and the daily turbulence of our busy lives, our world is changing at speeds that boggle the mind.

Humans are clearly the engine driving this planetary evolution. In part it's the carbon we pump into the air.

But it's also the critters we carry with us as we hustle and bustle around the globe.

In the short to mid term, invasive species transported by people will likely have a far more profound impact on our ecosystems than changing temperature.

Chris Knight reported recently in the Adirondack Enterprise on the Emerald ash borer, a type of beetle now in Western New York, Quebec and Ontario.

This invader, carried in bundles of firewood, is likely to kill most of the trees along the shore of Lake Flower in my home town of Saranac Lake.

white_noseIt's also likely that white nose syndrome, the fungus that's eradicating bats in the Northeast, was introduced from Europe by humans.

(Candace Page, the Burlington Free Press's environmental writer, had a brilliant piece about WNS in Sunday's edition.)

The catalog of invaders seems to grow daily: zebra mussels, lamprey, "creek snot," Eurasian watermilfoil...

As these organisms eclipse or weaken native populations, altering the food chain, we could see dramatic changes in the fabric of our forests and waterways.

This has happened before on a smaller scale. Dutch elm disease was likely introduced to the United States in a shipment of wooden furniture from the Netherlands.

Through the 1900s, the fungus altered the landscape of urban America, destroying many of the trees that decorated avenues and neighborhoods.

The event we experience could be far more dramatic. What happens if 90% of bat species are abruptly extirpated?

What happens if ash trees -- 7% of the forests in New York state -- are decimated?

Add to those stresses the incremental pressure of changing temperatures and weather patterns.

In short, humans are conducting a kind of accidental experiment, heating the planet and mixing its ingredients with a giant spoon.

The twist, of course, is that we live inside the Petri dish.

Tomorrow during our regional broadcast, I'll report on white nose syndrome research continuing in the Champlain town of Willsboro.

Read The In Box blog at link.

Photo of bats with white nose syndrome by Al Hicks, NYSDEC.


Spiny water flea threatens lake's food web

By Candace Page,

water_fleaA leading lake researcher is warning a new invasive species that “is at our doorstep” represents a serious threat to the Lake Champlain ecosystem.

The invader is the spiny water flea, a tiny crustacean that can do outsize damage, said Tim Mihuc, director of the Lake Champlain Research Institute at the State University of New York in Plattsburgh. Mihuc said the flea represents “perhaps the final nail in the coffin for Lake Champlain.”

While other scientists and lake advocates use less-apocalyptic language to describe the threat, there is general agreement that the water flea could disrupt the Champlain food chain and make game fishing more difficult.

“The flea is undesirable food for fish. I’ve seen video of small perch trying to swallow them and spitting them out. It’s like eating toothpicks,” said Doug Jensen of Duluth, Minn., who works in a program to prevent the flea’s further spread in his state.

The flea’s imminent arrival here — it has invaded a nearby New York lake — has lent new urgency to talks about how to stop invasive species from traveling through the Champlain Canal between the Hudson River and Lake Champlain. [...]

Anglers fear the water fleas in part because their thorn-like spines attach to fishing line, collecting in large globs that make trolling difficult or impossible.

In Vermont, Mihuc’s cry has been taken up by Lake Champlain International, the angling group, whose leader is urging the state Agency of Natural Resources to help prevent the water flea from reaching the state.

“Scientists have been warning about this threat, but they have a hard time getting traction with anybody but the fishing community,” LCI Executive Director James Ehlers said. “There are 21,000 LCI anglers. We want to know how we can help.”

The threat to Lake Champlain became more immediate last year when the creature was found in Great Sacandaga Lake, just west of Glens Falls.

The lake flows into the Sacandaga River, a tributary of the Hudson. The Champlain Canal connects the Hudson to Lake Champlain, providing the flea with a watery highway from New York to Vermont.

“The introduction of this exotic animal to a freshwater lake may ultimately destroy the natural food web resulting in a potential collapse of the game fishery,” Mihuc wrote last week to Ehlers. Mihuc is an expert on the lake’s plankton communities, the microscopic plants and animals that serve as food for larger creatures. [...]

Spiny water fleas have yet to reach the Champlain Canal, water samples taken this summer have shown. But the threat has mobilized new cooperation between the New York State Canal Corp., the Lake Champlain Basin Program and the U.S. Fish and Wildlife Service. [...]

Read the full story at link.


Invasive water plants make inroads on Long Island

By Jennifer Smith, Newsday

water_chestnutNot long after last month's declaration that the Peconic River was free of a pesky invasive plant called water primrose, state biologists made a disheartening discovery about 25 miles west.

A few dozen stems of hydrilla - a voracious Southern weed that has choked bodies of water across the Northeast - were growing in Lake Ronkonkoma.

First spotted upstate last summer, hydrilla has since made inroads on Long Island, turning up at lakes in Sayville and Smithtown.

"It makes dense mats of vegetation; you can't rowboat through it," said Charles Guthrie, regional fisheries manager for the state Department of Environmental Conservation. "If it were to come in and get established in other places, it could cause real problems."

Invasive aquatic plants crowd out native flora, hurt fish by robbing water of oxygen as the plants wither and decompose, and render lakes impassable to boaters and fishermen. The discovery last month at Lake Ronkonkoma highlights the challenges that officials and environmental advocates face as they struggle to keep these invaders out of local waters. Each year, invasive aquatic plants have a nationwide economic impact of $500 million, estimated a 2003 report from Cornell University. [...]

Local laws banning the sale of some invasive plants are being phased in by Nassau and Suffolk, and the state is working on its own list of nonnative species with an eye to future regulation.

But with little state or federal money to pay for eradication, the problem continues even as local governments dispatch aquatic mowers and weed-eating fish, and as volunteers labor to pull invaders from some of Long Island's best-loved water bodies. [...]

Read the full story at link.

Photo credit: Howard Schnapp | Volunteers remove invasive Water Chestnut plants from Mill Pond in Oyster Bay. / July 8, 2009


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