Displaying items by tag: invasive species

Wild hogs root in a sensitive area in Big South Fork National River and Recreation Area.  National Park Service

Tennessee side of Big South Fork best for hunting invasive hogs

Daniel Banks is a public information officer at Big South Fork National River and Recreation Area.

ONEIDA — Deer hunting season opened in Kentucky on Sept. 7 and opens in Tennessee on Sept. 28. During these big game seasons, wild hogs may be harvested by licensed hunters with the appropriate weapon that is legal for that specific season.

There is also an extended hog hunting season that lasts from the end of the deer season until the end of February with a weapon that is approved by that state for harvesting big game.

The wild hog is an invasive exotic species that has a significant negative impact on native species and do a great deal of damage to farmlands and residential areas. The damage they cause threatens park resources, including federally listed plants. (Their rooting also damages salamander and other amphibian habitat).

(Check out this video of natural pest control: A bear eating a hog in Great Smoky Mountains National Park).

Joro (pronounced “Joe-row”) spiders have made their way to the U.S. from Asia. They may appear intimidating, and can bite like most spiders, but are harmless when left alone.  Pexels via Virginia Tech

Newest invasive exotic spider is harmless, though it doesn’t belong here

Theresa “Tree” Dellinger is a diagnostician at the Insect Identification Lab in the Department of Entomology at Virginia Tech, where she identifies insects and other arthropods and provides management suggestions for insect-related problems. This article was provided by Virginia Tech.

BLACKSBURG — The large, brightly colored Joro spider has been sighted recently on social media in many more places than it has ever been seen in the United States, as exaggerated, misleading stories about the arachnid have gone viral. Yet they pose no threat, except perhaps to insects and to other spiders.

“Joro spiders will likely continue to spread in the U.S., but they aren’t the ‘flying venomous spider invasion’ that’s been sensationalized in the media,” said Virginia Tech entomologist Theresa Dellinger. Answering the questions below, she shared facts about this much maligned spider species.

Q: Where do Joro spiders come from?

“Joro spiders (Trichonephila clavata) are native to east Asia and can be found in Japan, Korea, China, Indochina and Nepal. First reported in northern Georgia in 2014, they are an invasive species of spider that likely entered the U.S. on materials imported from east Asia.” 

Regina Santore with the Wild Ones Smoky Mountains Chapter puts garlic mustard into a bag during an April volunteer event along a greenway in Oak Ridge.  Ben Pounds/Hellbender Press

Volunteers fight exotic and invasive garlic mustard on Oak Ridge greenway 

OAK RIDGE — Plants from around the world are overrunning the Southeast’s wild places, causing problems for native flora and fauna.

It’s a problem that’s grabbed the attention and work of dedicated organizations. One of them, the Tennessee Invasive Plant Council has many strategies to solve this problem: volunteer weed-pulling events, guides to help gardeners find native plants from which to choose, and even legislation. Its vice president, Jamie Herold, has many thoughts on the issue. She was eager to share them over pizza after a morning of pulling one such invasive, garlic mustard, at an event in Oak Ridge organized by Tennessee Citizens for Wilderness Planning, and Greenways Oak Ridge. 

The event involved pulling garlic mustard, a plant originally from Europe, from the edge of the woods behind apartments on West Vanderbilt Avenue. This area includes the Wildflower Greenway, a trail full of wildflowers that locals have been eager to protect from the garlic mustard’s domination. 

Cynthia Maples, the head beekeeper at Zoo Knoxville, checks out her buzzing charges.  JJ Stambaugh

With no clear cause, after two decades beekeepers across North America report losing up to 90 percent of their hives.

Although the alarming losses of the 2006-7 season have not repeated, since then, experts consistently track higher than normal winter losses among honeybee colonies, according to the U.S. Environmental Protection Agency (EPA).

A survey by the University of Maryland University of Maryland found 40% of US honeybee colonies died between April 2018 and April 2019.

While most Americans associate the insects with one of humankind’s oldest sweet treats - honey - they might not realize honeybees are actually an invasive species that can end up competing for resources with indigenous “pollinators” such as bumblebees. 

“Worldwide, there are over 20,000 species of bees,” said Cynthia Maples, the lead beekeeper and apiarist at Zoo Knoxville. “About 265 of those are bumble bees. In North America, there are 46 bumblebee species. In the southeast, we have about 15 bumble species with at least six of those in decline.”

Maples explained all bees are part of the order Hymenoptera, which also includes ants and wasps.

“Native pollinators would classify as those species naturally occurring in a particular area, not introduced. Honeybees are technically an invasive species to North America. They were brought over from Europe by humans,” she said.

“In the past few years the narrative has made a switch from keeping honeybees to help native pollinators to the realization that honeybees may be stealing resources from native pollinators,” she continued. “Honeybees are still very important as agricultural pollinators, but protecting native pollinators is also very important.”

While Maples doesn’t know if local bee populations are on the ropes, she said the Xerces Society for Invertebrate Conservation (an international nonprofit group) has formed regional “community science groups” as part of a widespread effort to track bumblebee species. 

“It’s really hard to say specifically if there has been a decline in local insect populations since insects are very difficult to track,” she said. “I took part in the training for the southeast bumble bee atlas earlier this year. The hope is that this atlas will give scientists a better idea of population numbers.”

It’s important that scientists understand any threats to the health of the world’s bee populations as the insects are vital to humankind’s ability to survive.

Bees — both domesticated and wild — are responsible for pollinating 71 of the 100 crop species that provide 90 percent of the global food supply, according to experts from greentumble.

Without bees, for instance, there would be no apples, avocados, onions, cucumbers, oranges or almonds. 

“Pollination is defined as the act of transferring pollen grains from the male anther of a flower to the female stigma,” Maples explained. “When bees go from flower to flower collecting pollen, they are also depositing pollen grains onto the flowers, thus pollinating them. Not all plants rely on insects to reproduce; for example, some are wind pollinated.”

“The bees benefit because nectar and pollen are their food source. Nectar is an energy source and pollen is a protein source for them. Many agricultural plants are pollinated by bees, hence their importance for us. Roughly one in three bites of food are pollinated by bees, plus another 25 percent of animal feed stuffs. Almonds are 100 percent honeybee pollinated.”

It’s not entirely clear why bee populations appear to be shrinking, but Maples said there’s no shortage of possible explanations.

“As with many species in decline, there are a number of reasons behind it,” she said. “Habitat loss is a big one. Our culture has taught us that we should have pristine lawns without ‘weeds,’ but letting your yard — even in part — grow wild would be a huge step in creating more resources for pollinators. Dandelions and clover can be a haven for pollinators.”

Poisons used to control unwanted animals and insects are another factor. 

“Pesticides have a huge impact as well, especially though containing neonicotinoids,” she said. “Pesticides rarely distinguish between beneficial invertebrates and those that cause harm.”

This summer’s historic heatwaves in the Northern Hemisphere may also be playing a role, but Maples cautioned that it’s too early to know for certain what the impact is. 

“Climate change may also be playing a role,” she explained. “It isn’t clear if bumblebees are adapting to changing temperatures within their normal ranges.” 

Those interested in helping researchers to track bee populations can go to Xerces and learn about taking part in one of the organization’s community science groups.

Do bees really have knees? And more on the idiom.

OAK RIDGE — Tennessee Citizens for Wilderness Planning will for the second year host a group of volunteers from Transformation Church on July 15 at the Worthington Cemetery Ecological Study Area to remove Dahurian buckthorn and other invasive species. This is the second year of help at the site from church members, and is one of several service projects church members will conduct throughout the Knoxville area. Volunteers will also help pick up litter and do some trail work.

Additional volunteers are needed to work with the Transformation Church group. We’ll meet at Elza Gate Park in Oak Ridge at 10 a.m. and plan to work until 2 p.m.; a pizza lunch will be provided. Bring bug spray and loppers and/or clippers, and wear sturdy shoes and clothing. Minors will need a parent’s/guardian’s signature on a waiver form (to be provided) in order to participate. For additional information, contact Jimmy Groton at This email address is being protected from spambots. You need JavaScript enabled to view it..

— Tennessee Citizens for Wilderness Planning

Many climate-change related issues have appeared since publication of this vintage map of Great Smoky Mountains National Park. Library of Congress

Invasive insects are among the vanguard of noticeable climate changes in America’s most-visited national park

GATLINBURG — Ants scurry beneath the carpet of last year’s leaves in Great Smoky Mountains National Park. The native ants are busy spreading the seeds of violets and bloodroot, preparing a new carpet of spring wildflowers to draw thousands of visitors.

But the local insects aren’t alone under there. They have become prey to venomous Asian needle ants that also prowl the leaf litter.

These invaders dine on termites, other ants and insects, while stealing habitat from them. Unlike invasive fire ants, needle ants can live in pristine forests and build large colonies with hundreds of queens. But like fire ants, needle ants have a painful sting that can trigger an allergic reaction. 

Climate change is expected to make it easier for invasive species like needle ants to upset the delicate balance of this temperate rainforest full of rare plants and animals. That’s just one example.

USGS

New York Times: Evolving native predation may help stem invasion of Burmese python

The proliferation of the exotic and invasive Burmese python in the swamps and wilds of Florida is demonstrably bad for native birds and mammals.

Researchers now have evidence the best solution might have been there all along.

A bobcat was captured on a trail camera by the U.S. Geological Survey eating python eggs and challenging one of the gigantic snakes. It was the first instance of natural, native predation on the snake’s eggs. Bobcats are already known to target reptile eggs, including those of sea turtles.

“While it is possible that this interaction was just an isolated incident, it is also possible that native species are beginning to respond to the presence of the python,” the New York Times reported.

“‘Most cat species adapt their diet to what is available, so bobcats predating on python eggs is actually not that surprising’” said Mathias Tobler, a wildlife ecologist at the San Diego Zoo Wildlife Alliance.”

WATE: Commercial fishing pulls out 10 million pounds of exotic carp from Tennessee River system

If you never thought there’d be an Asian carp commercial fishery in Tennessee waters, you were wrong.

Tennessee Wildlife Resources Agency’s Asian Carp Harvest Incentive Program has yielded 10 million pounds of the exotic fish since 2018, the bulk caught downstream on the Tennessee River system at Kentucky and Barkly reservoirs. The fish has been spotted as far upstream as Knox and Anderson counties.

The Tennessee Valley Authority and TWRA are experimenting with acoustic barriers to prevent further upstream spread of the fish, which compete with native fish for food and habitat.

“There are four types of Asian carp: bighead, silver, black and grass,” WATE reported. “Experts say the species threatens to disrupt aquatic ecosystems and starve out native species due to their ability to out-compete native species for food like plankton.”

So what do fishermen do with 10 million pounds of carp?

It can be sold to wholesalers for distribution abroad and also makes for really good fertilizer.

Virtual Volunteer Forester Registration

Class cost is $25. More information and financial aid available on the registration site.

Cedar Barrens — a habitat characteristic of our ecoregion — have become scarce in East Tennessee. They are reduced or eliminated by economic development and our rare native species specialized to live in them get overwhelmed by invasives. 

For more information, contact Tim Bigelow at 865-607-6781 or This email address is being protected from spambots. You need JavaScript enabled to view it.

Specifics subject to prevailing conditions at time of event. COVID-19 precautions will be observed. 

A life dedicated to the flora of Tennessee

Dr. Hal DeSelm clambered around the crest of Cherokee Bluff in the heat of a late Knoxville summer 22 years ago. The Tennessee River flowed languidly some 500 feet below. Beyond the river stood the campus of the University of Tennessee Agriculture Institute. The towers of the city center rose to the northeast beyond the bridges of the old frontier river town.

DeSelm was not interested in the views of the urban landscape below. He was interested in the native trees, shrubs, herbs and grasses that clung to the ancient cliffside with firm but ultimately ephemeral grips on the craggy soil.

The retired UT professor, a renowned ecologist and botanist who died in 2011, had been sampling the terrestrial flora of Tennessee for decades. The life-long project took on a new urgency in the early 1990s, when he accelerated his data collection in hopes of writing the authoritative guide to the natural vegetation native to the forests, barrens, bogs and prairies of pre-European Tennessee.

Between 1993 and 2002, DeSelm collected 4,184 data points from 3,657 plots across the state. Many of those plots have since been lost to development, highways, and agriculture, or overrun by exotic species, but he assembled an invaluable baseline of the native landscape. Many of the sites he recorded have since been lost to development.