Arlington Regional Master Naturalists

It Takes a Community to Nurture a Habitat

Text and photos by Jackie Rivas

Our natural world is under siege by invasive plant species that outcompete native species for sunlight and water, quickly overwhelming the native habitat and eliminating food and shelter for birds, butterflies, and other pollinators. We have a biodiversity crisis, and these invasive species are part of the problem.

Fortunately, groups of concerned nature lovers are tackling the crisis, community by community. In Arlington, the latest example is a collaborative project of the Arlington Regional Master Naturalists (ARMN), the Audubon Society of Northern Virginia (ASNV), and a private swimming pool club called the Dominion Hills Area Recreation Association (DHARA), off Wilson Boulevard.

The pool property includes a wooded area that backs up to Reeves Creek, far from the pool and clubhouse. This area had become severely overgrown with invasive species. The pool’s directors knew there was a problem and they attempted to control it, but competing priorities prevailed.

However, because the property is adjacent to parklands that are already being rehabilitated through ARMN’s park steward program—Powhatan Springs and Upton Hill—it was deemed to be strategically important and deserving of assistance from ARMN and ANSV.

ASNV and ARMN member Carolyn McGavock pitched the idea of a community project to the DHARA Board. When the Board graciously welcomed the assistance, ARMN’s Bill Browning and Joan Haffey of ASNV (and ARMN) presented the
DHARA management with an invasive plant removal and habitat restoration plan.

Bush honeysuckle and other invasives blanket the ground and trees at a remote part of the Dominion Hills pool property. Photo by Jackie Rivas.

Habitat restoration is a long-term project. The first step is to remove and control the invasive plants, no mean feat. Then native plants are installed and nurtured until they are established.

Native plants will provide the necessary food and shelter to attract native birds and other fauna. ASNV and ARMN members will monitor and evaluate changes, primarily through measuring the extent of habitat restored as well as noting observations posted to eBird (an online database of bird observations) to track bird species and abundance over time. ARMN also plans to document the restoration progress
with photographs through the duration of the project.

A number of mature canopy trees near Reeves Creek are threatened by English ivy (Hedera helix). English ivy is very harmful to trees big and small. Its dense evergreen foliage blocks sunlight from reaching the tree’s leaves and the forest floor. When weighed down by snow and ice, ivy can break branches and even topple tall trees.

It wreaks havoc on saplings as well. Ivy’s rootlets wrap around bark and provide an environment for disease and decay, killing the tree in the process. On the ground, ivy provides an ideal habitat for mosquitoes.

Bush honeysuckle also found a hospitable environment at the rear of the DHARA property. The three most common types of bush honeysuckle in our area are: Amur (Lonicera maackii), from China; Morrow’s (Lonicera morrowii), from Japan; and Tatarian (Lonicera tatarica), from Russia.

These plants produce leaves in early spring and grow rapidly, stealing sunshine and crowding out native plants. Their bright red berries tempt migratory birds in the fall, but the berries lack the fat and other nutrients that the birds need for their long journey. And, unfortunately, after consuming the berries, birds expel the seeds conveniently wrapped in fertilizer, ready to start another crop of bush honeysuckle in their flight path.

A team of nature lovers began the project of clearing out the invasive plants over the weekend of June 23, 2023. Volunteers came from many different community organizations: ARMN, DHARA, ASNV, Tree Stewards of Arlington and Alexandria, and Chesapeake Climate Action Network, among others. It was also a family affair with a number of kids lending a helping hand.

On Sunday, June 25, about twenty-five community volunteers and their families joined the effort. Geoff Vaughan, DHARA Board Member and Executive Committee Member, was wielding a power saw to cut back the bush honeysuckle. He had been tackling the English ivy on his own for the past few years. While he found removing the ivy therapeutic during the pandemic, it was a Sisyphean task for a one-
person operation. Geoff welcomes the additional help to contribute to general habitat restoration.

Karen Kirchoff, Dominion Hills pool member, brought her two kids, Greta, who will be entering Swanson Middle School in the fall and Cam, a rising 6th grader there, to help out. Karen wants to instill a volunteer spirit in her kids as well as an appreciation of nature. Prior to this event, they participated in stream clean-ups and other environmental activities.

Clearing the area of invasives, as volunteers did in this section of the Dominion Hills property, is the first step in the long process of habitat restoration. Photo by Jackie Rivas.

ASNV representatives were present as well. Carlyn Kranking, enthusiastic invasive fighter, learned through an ASNV email about the opportunity to support wildlife in Northern Virginia. She was keen to give birds a reason to come to Arlington.

ASNV Board and ARMN member Joan Haffey was chopping bush honeysuckle on behalf of ASNV’s new program, Stretch Our Parks. This is “both a conservation and a social initiative, aimed at improving and creating wildlife habitat while building a greater commitment by a broader northern Virginia community in saving wildlife” and supporting their local parks.

ASNV chose to launch its initiative here to accelerate the efforts of many partners—led by ARMN park stewards and including ASNV—already working together at Upton Hill Regional Park and Powhatan Springs Skate Park.

Under Stretch Our Parks, ASNV facilitated the newest partnership in that effort with DHARA, extending the corridor further east. ASNV is also partnering with the Lockwood/Elmwood senior housing complex adjacent to Upton Hill Regional Park on a restoration effort.

The restoration project at the Dominion Hills pool property builds directly on the successful restoration work done by ARMN next door at Powhatan Springs Skate Park and Upton Hill Regional Park (where ARMN park stewards Bill Browning and Jill Barker have been leading invasive removal efforts for years).

Unencumbered by English ivy and other invasive plants, Arlington’s tree canopy and understory have a chance to thrive and support native wildlife.

The first step in liberating trees from English ivy is to sever the vines at the base of the encumbered tree. Then uproot the vines, if possible. But leave the ivy above the severed part on the tree to avoid damaging the tree bark. Without nutrients from its roots the ivy will dry out and fall off over time. For bush honeysuckle, the treatment is to cut the stump down to about six inches. Then treat the stumpwith a small dab of herbicide.

It takes a community to ensure that our flora and fauna will be here for generations to come!

Nature’s Notebook Recognizes ARMN Citizen Scientists

By Rosemary Jann, Phenology Program Leader

For the second year in a row, ARMN’s phenology project has been recognized as a top contributor of observations for Nature’s Notebook’s “Nectar Connectors” campaign.

Nature’s Notebook, the database tool of the USA National Phenology Network, enables volunteer citizen scientists to submit observations that chart the timing and intensity in the growth cycles of plants and animals.

Pollinator insects like monarch butterflies need nectar to survive, so knowing when peak bloom, and thus peak nectar availability, occur for particular plant species can provide natural resource managers with information to match plantings with the pollinators in their areas.

Plants monitored by the ARMN team include, from top left: Swamp milkweed and cardinal flower (both photos by Rosemary Jann) and Buttonbush (photo by Katherine Wychulis. In the bottom photo, also by Katherine Wychulia, a common European greenbottle fly visits aswamp milkweed at the Arlington Central Library Garden.

This kind of phenological research can also document the effects of climate change. For instance, if earlier spring warmth is causing pollinator plants to bloom earlier, before the insects that need them have hatched or arrived, both pollination and insect survival can be negatively impacted.

More than 15,000 individuals nationwide contribute observations to Nature’s Notebook, ARMN decided to form a “Local Phenology Program” at the beginning of 2022 so that multiple team members could contribute observations to the same database, thus expanding the quantity and usefulness of our data.

Since then, ARMN’s team has placed twice in the top six contributors to the “Nectar Connectors” campaign, out of 55 participating local programs nationwide.

Four species, two monitoring sites

Team members earned this distinction by sharing weekly monitoring duties for four different “Nectar Connector” species: swamp milkweed (Asclepias incarnata), butterfly weed (Asclepias tuberosa), buttonbush (Cephalanthus occidentalis), and cardinal flower (Lobelia cardinalis). The monitored plants are at two of ARMN’s native plant demonstration gardens, at the Arlington Central Library and at Potomac Overlook Regional Park.

Congratulations and thanks are in order for the ARMN phenology team: Noreen Hannigan, Ginger Hays, Katherine Wychulis, and Elise Millstein at Central Library; and Gary Shinners, Carol Abel, David Evans, Carol Weldon, and Kit Britton at Potomac Overlook. Together they’ve shown the power of dedicated teamwork to expand the value of citizen science.

ARMN Ozone Team Hosts Event for the International Day of Clean Air

By Barbara Hoffheins

ARMN’s Ozone Bioindicator Garden at Walter Reed Community Center (WRCC) in Arlington was recently the site of an event to commemorate the International Day of Clean Air. This occasion corresponded wonderfully with the objective of the ozone garden: to collect data on the impact of tropospheric or ground level-ozone air pollution on plants.

ARMN installed the bioindicator garden in 2020 in cooperation with NASA, the Harvard Smithsonian Center for Astrophysics Science Education, and Arlington County.

Planning for the event began when Laura Fuller from the United Nations Environmental Programme (UNEP) office in Washington, DC, contacted ARMN member Jane Metcalf (an original member of the ozone garden team) to determine whether UNEP could meet at the Ozone Garden to celebrate the International Day of Clean Air for blue skies 2023 on September 7.

From there, members of Team Ozone (Todd Minners, Bridget Baron, Anne Doll, Jon Bell, and Barbara Hoffheins) worked with UNEP staff to design the event. With the exceptional help of staff at the community center, they were able to secure space for an in-person and virtual meeting.

The UN designated the day to acknowledge the need to improve air quality. The International Institute for Sustainable Development states that “The International Day of Clean Air is commemorated annually on 7 September in recognition of the fact that clean air is important for the health and day-to-day lives of people, while air pollution is the single greatest environmental risk to human health and one of the main avoidable causes of death and disease globally.”

The event included speakers from the United Nations, NASA, the U.S. Department of Energy, Howard University, and the Pan American Health Organization (PAHO).

Panel (l-r): Rafael Peralta, UNEP; John Haynes, NASA; Kelly Crawford, U.S. Dept. of Energy; Joseph Wilkins, Howard University; Daniel Buss, Pan American Health Organization; and Sandra Cavalieri, Climate and Clean Air Coalition; Photo by Lea Schlatter.

Rafael Peralta, Director, North America Office of UNEP, opened with an overview of the program. John Haynes, Program Manager, NASA Health and Air Quality Applications, discussed a new satellite, TEMPO (Tropospheric Emissions: Monitoring of Pollution), which was launched April 7 for placement in a geostationary orbit to measure air pollution over North America. The TEMPO quick facts site states that: “Due to the high spatial and temporal resolution of the spectrometer, TEMPO data will improve emission inventories, monitor population exposure to pollution, and make it possible for regulatory agencies to implement effective emission control strategies.”

Kelly Crawford, Department of Energy Senior Advisor for Energy Equity and Environmental Justice, said her office uses information from sources like TEMPO to target neighborhoods and regions of poor air quality for installation of clean energy systems such as solar power under the Infrastructure Reduction Act. Her
office also supports related research at minority universities.

Dr. Joseph Wilkins, Assistant Professor for Atmospheric Science at Howard University, discussed air quality research in which data from sources like TEMPO are analyzed and interpreted to understand pollution impacts. He also discussed Howard’s emphasis on preparing students for the workforce and described numerous scientific missions that give atmospheric science graduate students direct, hands-on experience.

Sandra Cavalieri, Hub Manager for the Climate and Clean Air Coalition (CCAC) addressed the current issues in pollution reduction. The CCAC is a UNEP program with the goal of reducing short-lived climate pollutants that can quickly impact global warming, air quality, food security and human health. Its members include Bangladesh, Canada, Ghana, Mexico, Sweden, and the United States.

Daniel Buss, Unit Chief for Climate Change and Health at the Pan American Health Organization, described his organization’s efforts to reduce the use of solid fuels in the Americas that contribute to hundreds of thousands of premature deaths per year from outdoor and indoor air pollution.

In addition, Todd Minners gave an overview of ARMN and its roles in the community and Barbara Hoffheins introduced the audience to the ARMN Ozone Garden.

At the garden: Left to right, Laura Fuller and Rafael Peralta, UNEP; John Haynes, NASA; Kelly Crawford, Dept. of Energy; Joseph Wilkins, Howard University. Photo by Todd Merriman

From there, the meeting went outside where everyone viewed the Ozone Garden and inspected the plants. Petya Campbell and Pawan Gupta from NASA Goddard Space Flight Center, Biospheric Sciences Laboratory, demonstrated portable instruments for gauging leaf health and measuring PM 2.5 (particulate matter). Ozone team members also used the equipment to take measurements of the plants.

About 40 people attended, including graduate students from Howard University, George Washington University, and University of Maryland, and members of the public. The event could also be viewed virtually.

All in all, it was an interesting event that also generated more awareness of ARMN programs. ARMN hopes for greater collaboration with Howard University for rigorous study at the garden. Dr. Wilkins expressed interest in installing an ozone sensor and two of his students indicated interest in collecting and interpreting data for their projects.

Stay tuned for updates later this year on the Ozone Garden’s progress and information collection. For additional background, see these blogs on the garden from 2021 and 2022.

Bluebirds Find New Homes in Barcroft Park

By Liz Macklin

Early this spring in Arlington’s Barcroft Park, in clearings far from busy athletic fields, volunteers installed two boxes for nesting Eastern Bluebirds (Sialia sialis). Painted white to minimize heat from the sun, the boxes sat atop tall metal poles with baffles attached to prevent hungry snakes and other predators from climbing. Wire guards were set around the entry holes to keep out prying raccoon hands.

The stage was set. Only time would tell whether any birds would take them up on the offer.

ARMN volunteer Manoma Sirisena checks on one of the new bluebird boxes, set up in a clearing with lots of food for baby birds and their parents. The cylindrical baffle on the pole is designed to keep out snakes. Photo by Nancy Cleeland

The Barcroft project is a joint effort by Arlington Regional Master Naturalists (ARMN) volunteers and the Virginia Bluebird Society, which provided the houses, protective baffles and poles.VBS President Valerie Gaffney even helped with the installation in March. Arlington County Natural Resources Manager Alonso Abugattas assisted in choosing the sites, to ensure there would be plenty of plants and insects to sustain the birds and their young.

The boxes are additions to a bird trail created in 2019 by Arlington resident and volunteer Ron Knipling, who passed away this year. Knipling and his team installed 19 small boxes suitable for chickadees and wrens (who sometimes fight over them). Bird boxes provide important habitat for bluebirds and other cavity nesting birds.

In March, ARMN volunteers Mark Colgan, Manoma Sirisena and Emily Apgar agreed to monitor the original boxes along with the two new ones. Five additional volunteers joined the team. Every week through the spring and summer, they visited all 21 birdhouses spread through the woods, recording their observations in an online log.

The first sign of bird activity was noted on April 2, when observers found evidence of chickadee nest building, including bits of moss, in four of the small boxes.

Bluebird eggs were discovered in the new box, and later monitors observed the nestlings that hatched from them. Photos by Mark Colgan

Bluebirds arrived around April 7. Their presence was announced by straw nesting material showing up in one of the two new birdboxes. The next week, monitors noticed a bluebird fly out of the same box as they approached. Inside was a cup-shaped nest, but no eggs. Anticipation mounted until April 19, when Emily peered into the box to find three eggs. Within a week the count rose to five.

A female bluebird enters the box with food for the nestlings and leaves with a fecal sac, to keep the nest clean. Photos by David Howell

By May 5, monitors found that four of the bluebird nestlings had hatched, and the fifth followed soon after. The parents stayed busy gathering insects for the brood and keeping the nest clean and safe.

During this time, eggs in the chickadee nests began to hatch and live nestlings were observed. However, in one of the boxes several chicks were missing and the remaining two were dead. The missing and dead chicks were presumed to be the victims of predation, because the smaller boxes had no protection against snakes or raccoons.

On May 19, Mark discovered a five-foot Eastern Rat Snake (Pantherophis alleghaniensis) only a foot from the bluebird box that had an active nest. As the mother bird waited in a tree, the snake paused and then slid away. A few days later, a snake was seen coiled under the baffle, unable to pass.

Birds nesting in the unprotected original boxes suffered continued losses. Chickadees were documented to have fledged successfully from only one nest. As the boxes were vacated by chickadees, House Wrens (Troglodytes aedon) built nests in their place. The wrens appeared to be equally vulnerable to predators, as monitors noted missing nestlings and a cracked egg.

To improve the smaller birds’ chances of survival, the original birdhouses will be replaced by new ones equipped with protective baffles and guards against snakes, raccoons and other predators.

For the bluebirds, success came with one of the new boxes. It is believed that five young birds fledged from that nest. On June 10, Mark cleaned out the nest, providing a chance for birds to build a second nest. Smaller birds use the bluebird boxes too, and wrens did build a nest and had three eggs, but they were apparently abandoned. The second new box never attracted bluebirds in its first year, but did produce a successful family of wrens.

With late summer signaling an end to nesting season, all of the Barcroft boxes were cleared of nesting materials and brushed clean. The season starts up again in early spring, when the team plans to add a third bluebird box. They will also remove the remaining original bird boxes and replace them with boxes that offer protection against snakes and other predators.

The long-term plan for Barcroft is to have three nesting boxes for bluebirds and three for chickadees or other small birds. “I’m really looking forward to next season,” said Emily Apgar. “My knowledge has grown by leaps and bounds, observing how the birds, particularly the bluebirds, react and interact with their environment.”

Meet Virginia’s Three Venomous Snakes, and a Common One That’s Harmless

By Colleen O’Hara
Photos by John White/Virginia Herpetological Society

Snakes love summer’s heat, so you’re more likely to spot them these days while out on a hike or even in your yard. But don’t worry: There’s typically nothing to fear from these encounters.

Of the 34 snake species and subspecies in Virginia, nearly all are harmless to humans. This includes the intimidating yet nonvenomous Eastern Ratsnake (Pantherophis obsoletus) (formerly known as the Black Ratsnake), which can grow up to six feet, making it the longest snake in Virginia. It’s one of the most common snakes in our area.

Adult Eastern ratsnake, and its strikingly different juvenile form, among the most common in our area. Photos by John White/Virginia Herpetological Society

Only three of Virginia’s snakes are venomous: the Eastern Copperhead, the Northern Cottonmouth, and the Timber Rattlesnake. Here’s what you need to know about them:

Eastern Copperhead (Agkistrodon contortrix)

Eastern Copperhead photo by John White/Virginia Herpetological Society

The only venomous snake you’re likely to encounter in the Arlington area is the copperhead. This snake is one of the most widespread snake species in Virginia and can be found throughout the state in forests and upland rocky areas, alongside streams, in rock walls and wood stacks, and other locations.

The best way to identify a copperhead is by the dark bands across its back that look like two Hershey kisses touching, or an hourglass. They also have vertical pupils (if you happen to be that close to one to see) and a triangular head. Baby copperheads have a yellowish tail, but this goes away as they mature. A common perception is that baby copperheads are more venomous than adult copperheads, but they are not, according to Dr. Arianna Kuhn, Assistant Curator of Herpetology at the Virginia Museum of Natural History.

In fact, snakes typically only use their venom when they are targeting a food source, she said during a recent webinar on Virginia’s snakes. It’s in their best interest to warn something away or slither off rather than to engage. “There are more opportunities (for the snake) to become injured if it interacts or engages with the prey or predator,” Kuhn said.

If you want to protect yourself from copperheads and discourage them from your yard, the Virginia Herpetological Society has some suggestions: Keep vegetation trimmed, move piles of brush and leaves away from walkways and play areas, remove spilled bird seed that attracts rodents (a favorite food of copperheads), and wear heavy gloves if you are working with stacks of firewood.

Another good idea to avoid any snake, especially if you’re working in garden beds or hiking in vegetative areas, is to shuffle your feet so you don’t accidentally step on a snake. They will generally want to get out of your way rather than interact with you. See more about safety around copperheads at the VHS website.

Northern Cottonmouth (Agkistrodon piscivorus)

Northern Cottonmouth photo by John White/Virginia Herpetological Society

You’re not likely to encounter a venomous cottonmouth unless you live in the southeastern part of Virginia. However, they are often confused for harmless Northern Water Snakes (Nerodia sipedon sipedon) that are frequently found in the rivers and streams of Northern Virginia, and throughout the state.

Cottonmouths are semiaquatic, found in swamps, marshes, streams and rivers, and like to bask on the shoreline close to wet areas. They are sometimes referred to as Water Moccasins. Generally, cottonmouths are scared of people, Kuhn said, and it’s hard to get close to one, even to snap a picture. If you happen to irritate one, though, you might see it tilt its head back and open its mouth wide to scare you off. This is a behavior a water snake would never do, she said.

Timber Rattlesnake (Crotalus horridus)

Photo of Timber Rattlesnake by John White/Virginia Herpetological Society

The third venomous species in Virginia is the Timber Rattlesnake, which is endangered. They are found in southeastern Virginia, and also in the mountainous part of the state, but their range is fragmented, and their habitat is shrinking, Kuhn said. They prefer upland forests with ledges facing south in the spring and fall, and open woods and grass fields in the summertime.

The telltale rattle at the end of their tail starts out as a button, and then grows over time. (Contrary to popular belief, though, the length of the rattle does not indicate the age of the snake.) These snakes use their rattle to warn potential predators and also to distract prey. Timber Rattlesnakes prefer to eat mammals, but will also eat birds and frogs, according to the Virginia Herpetological Society.

Snakes are beneficial and probably won’t hurt you

Snakes often get a bad rap, but they are important to the ecosystem, Kuhn said. They help keep the rodent population in check and are food for larger predators. You’re more likely to get struck by lightning than die of a snake bite. In fact, only about five people die each year in the U.S. from a snake bite. The best way to not get bitten by a snake, she said, is to not handle one.

How well do you know Virginia snakes? Take the VHS quiz.

Global snake trivia: The longest snake in the world is the reticulated python, native to South and Southeast Asia. It can grow up to 32 feet and weigh up to 170 pounds. Meanwhile, weighing in at 550 pounds, the Green Anaconda, native to South America, is the heaviest snake in the world.

For more on snakes and other reptiles and amphibians, check out the Virginia Herpetological Society and Partners in Amphibian and Reptile Conservation.

Volunteers Share the Joy of Local Nature at the Four Mile Run Farmers and Artisans Market

By Eric Weyer

It is tempting to think of nature as something that exists only in wild, untouched places: the forests of the Blue Ridge Mountains, the salt marshes of the Eastern Shore, or the flood-swept islands of the Potomac. But the wondrous beauty of nature can be found even in the most developed of places.

Helping people see, treasure, and protect the natural world around them is the core mission behind the “Pop-Up Nature Centers,” hosted by the Arlington Regional Master Naturalists (ARMN) and the Four Mile Run Conservatory Foundation at the Four Mile Run Farmers and Artisans Market.

A market visitor stops to chat with Eric Weyer and take in exhibits on local nature at the pop-up nature center. Photo by Kurt Moser.

These (mostly) monthly events, held by Kurt Moser, Laura Bachle, Ruth Lane, Molly Tepper, and myself (Eric Weyer), have explored a variety of environmental topics relevant to the specific environment of Lower Four Mile Run.

Our latest event featured the turtles of Lower Four Mile Run. Visitors were attracted to turtle carapaces (the top of the turtle’s shell) and plastrons (the bottom of the turtle’s shell), the eggs of snapping turtles, and stuffed toy turtles of various species.

Topics covered at the Pop-Up Nature Centers have included “Pollinators,” “Geology,” “Social Insects,” “Winter Weather,” and “Birds.” Each event features displays and activities for visitors of all ages. Highlights of previous events include making real-feeling snow from baking soda and shaving cream, simulating the flow of water and the impact of pollution in the Four Mile Run watershed using an Enviroscape® model, and showing visitors what different types of pollen look like under a powerful microscope.

A chalkboard calls in visitors with the theme of the day – local turtles – while a table display shows the carapaces of various species. Photos by Eric Weyer

Once visitors were drawn in, Laura, Molly, and I used the displays to talk about the ecology of turtles, helped by Alonso Abugattas’ wonderful book, The Reptiles and Amphibians of the Washington DC Metro Area. Some were fascinated to learn that turtle shells are made of keratin—the same material that makes up fingernails.

Others were amazed to learn that the sex of a turtle is determined by the temperature of the turtle nest. Often, conversations revolved around turtles that visitors had seen in their backyards or in different parks around the area.

Visitors with kids were especially drawn to the different stuffed toy turtles. One child, the son of a market vendor, peppered me with questions about these turtle species. “What does a turtle’s skeleton look like?”, “How does the turtle eat its food?”, and the ever-popular “How do turtles poop?”

A hands-on turtle display includes stuffed toyes, a classic book, facts on turtles and a chance to make your own paper turtle. Photo by Eric Weyer.

After examining the stuffed turtles, many kids chose to join Molly and make a turtle of their own out of paper cutouts and egg cartons. They then had the chance to color their turtle as they saw fit.

At the end of their visit, whether short or long, visitors leave the center with smiles on their faces and a new sense of appreciation for nature in their own communities.

About the Four Mile Run Conservatory Foundation

The Four Mile Run Conservatory Foundation is a 501(c)3 organization that envisions the lower Four Mile Run as a cherished community resource and a model for natural lands stewardship in an urban setting. Its mission is to promote nature, culture, and community at the lower Four Mile Run through restoration, advocacy, recreation, and education.

Wasps and Beetles and Flies (Oh My!): They’re Pollinators and Much More

Photo of a hairy flower scarab beetle on a flower. The flower has a yellow center and white petals.

Text by Becky Hamm; images by Kent Anderson (aka “surfman”) in his iNaturalist entries, except as noted.

Ah, summer: Warm breezes, colorful flowers, and lots of pollinating butterflies, bees, and … beetles? Oh yes, and flies and wasps too.

While they might be overshadowed by pollinating insects that are cuter and more colorful, these less popular insects are also crucially important to the success of our food web.

These three types of winged insects are not what most people—including me!—think of when they consider “important” insects, but I was surprised to learn of their pollination, predation, and decomposition functions that enable us to have a balanced ecological system.

Non-bee pollinators are critical for pollinating much of the world’s agricultural crops. In fact, certain flies are starting to be bred specifically for the task since they are easier to raise than bees. Wasps are excellent predators of pest species, and beetles aid in decomposition of dead animals and plants. It is tempting to silo these insects into a single function, but many perform multiple tasks well, making them workhorses of the insect world. With the planet’s insect population in decline, we need to raise awareness of their importance.

Wasps

So formidable, there’s an NBA basketball team named after them (Charlotte Hornets), wasps are much feared in our culture. However, understanding their behavior may help you better understand their place in your yard.

Wasps are in the family Hymenoptera—cousins to bees and ants. Some wasps are eusocial, meaning they live together in a nest, typically with a queen. This includes species common in Virginia like the yellow jacket (Vespula spp.) and the paper wasp (Polistes spp.). These types of wasps are known to be aggressive but will leave you alone if unprovoked, so don’t swat at them! To discourage yellow jackets, make sure all trash is sealed off, especially fruit, sodas, and other sweets, as they are attracted to those food sources. (Yellow jackets are sometimes confused with honeybees. Here’s a guide to learn the difference.)

Wasps play an important role in our food web. And despite their bad rap, only 1.5% of wasp species are likely to sting people if provoked.

Photo of a wasp sitting on a white flower. — *Ichneumonid* family wasp, Subfamily *Cremastinae* (CC-BY-NC).

Most wasp species are solitary. Common solitary wasps in Virginia, like the scary-looking Ichneumonid (parasitic) wasp, pose no actual threat to humans or pets because they do not sting. Others, like the yellow-legged mud-dauber (Sceliphron caementarium) wasp that built a nest near my back door this summer, only sting if provoked.

Many people also assume that wasps are carnivores. However, it is more accurate to say that wasp larvae are carnivorous while adult wasps are herbivores, feeding primarily on nectar.

Wasps are known to visit between 20% and 25% of the world’s crops, making them important pollinators in agriculture. Some of their favorite native plants locally are goldenrod, mountain mint, and buttonbush.

However, wasps really shine when viewed as natural pest control, via predation and parasitism. Commonly seen in Virginia, the parasitoid braconid wasp, Cotesia congregates will lay eggs in the skin of the tomato hornworm. The hornworm is then rather gruesomely eaten from the inside out. The diminutive Aphidiinae are a subfamily of parasitic wasps that lays eggs on or near aphids, so their larvae have a ready-made meal next to them when they hatch.

Photo of a Hidalgo mason wasp on a flower — Hidalgo mason wasp (Euodynerus hidalgo) (CC-BY-NC).

Photo of a blue-winged scoliid wasp on a flower — Hidalgo mason wasp (Euodynerus hidalgo) (CC-BY-NC).

As predators, wasps help to control aphids, grasshoppers, beetles, caterpillars, and flies. For example, the Hidalgo Mason Wasp (Euodynerus hidalgo), Blue-winged Scoliid Wasp (Scolia dubia), and yellow jacket will paralyze their prey and bring them back to their nest for their larvae to eat.

Beetles

Beetles are the most diverse group of any living animal; there are nearly 30,000 species in North America alone. Beetles are distinguishable from other insects due to their hard outer forewings that protect a set of inner wings that are used in flight. While some beetles, especially those that are from other countries, are seen as pests both in the garden and agriculturally, many beetles serve ecological functions such as pollination, predation, and decomposition.

American Carrion Beetle (Necrophila americana) (CC-BY-NC).

If you have a compost pile, there is a good chance a species of beetle may be helping your table scraps decompose. Beetles such as the American Carrion Beetle (Necrophila americana) eat decaying plants and deceased animals, providing a miniature “trash removal” service for us.

Beetles were the first ever pollinators, starting to visit flowers in the Jurassic period. “Beetles are still the primary movers of pollen for numerous plant families, especially primitive ones like magnolias”, said Alonso Abugattas on his Capital Naturalist blog. In our area, they will feed on pollen and nectar from plants such as spicebush (Lindera spp.), yarrow (Achillea spp.), and sunflower (Helianthus spp.).

Photo of a firefly sitting on a leaf. — Hairy Flower Scarab Beetle (Trichiotinus affinis) (CC-BY-NC).

One beetle everyone likes is the firefly (Photuris spp.). Widely miscategorized as flies, fireflies are in the Lampyridae family of beetles. They are best known for their bioluminescence, though not all adults can produce light. They are also predators of snails, slugs, worms, or other insect larvae, and some adults eat pollen and nectar.

Flies

Photo of a golden-backed snipe fly on a leaf. The fly has a gold colored — Golden-backed Snipe Fly (Chrysopilus thoracicus). Photo by Steve Young.

There’s a world of flies beyond the common and annoying house fly or fruit fly. In fact, there are over 85,000 species in the order Diptera, including some remarkable beauties. Take a look at the Golden-backed Snipe Fly (Chrysopilus thoracicus), a stand-out that can be spotted on understory leaves locally in spring.

Believe it or not, we would be in trouble without flies: they are the second most common pollinator behind bees, even more helpful in crop pollination than butterflies!

Hoverflies (in the family Syrphidae, also known as Syrphid flies or flower flies) and metallic-colored blow flies (Calliphoridae family) are the “powerhouse” pollinators. Hoverflies are best known as bee mimics, usually sporting stripes that belie their inability to sting. Hoverflies are also capable of flying huge distances and some species are migratory, giving them the ability to spread pollen much further than most bees. They are known to lay their eggs near aphid infestations; they are tasty morsels for the larvae, which can eat up to 400 aphids before pupating.

Photo of a narrow-headed Marsh fly on flowers. — Narrow-headed Marsh Fly (type of Syrphid fly) (Helophilus fasciatus) (CC-BY-NC).

Photo of a Black-shouldered Drone Fly on flowers — Narrow-headed Marsh Fly (type of Syrphid fly) (Helophilus fasciatus) (CC-BY-NC).

Key players in a balanced ecosystem

To keep them around, try planting natives and avoid using pesticide sprays that will kill wasps, beetles, and flies along with mosquitoes. While you may also be trying to target aphids or pesky slugs, other beneficial insects are greatly affected by these chemicals. Also, consider letting leaves decompose naturally in beds and create a brush or dead wood pile, since many beetles, including fireflies, pupate in leaf litter while wasps use stems and wood to make their nests.

While they may never be cherished like butterflies or revered like bees, wasps, beetles, and flies play a key role in the ecosystem. Accepting and even celebrating their role in nature can help lead to a healthier world for all of us.

ARMN and the Alexandria Library System Enjoy a Tidy Collaboration at Four Mile Run Park

Photo of volunteers standing in front of the field station. Yellow bags of trash are in front.

Text and photos by Susan Berry, except as noted.

On Saturday June 3, 2023, ARMN co-hosted a successful tour and clean-up of Four Mile Run Park in Alexandria. This was the second time in 2023 that ARMN partnered with the Alexandria Library system to host a nature-based event. And we’re confident there will be opportunities for many more partnerships in the future.

Photo of entrance sign for Four Mile Run Park — Map of Four Mile Run Park.

Our tour leader for the June 3 event was Kurt Moser from the Four Mile Run Conservatory Foundation. This organization envisions the lower Four Mile Run as a cherished community resource and a model for natural lands stewardship in an urban setting. Its mission is to promote nature, culture, and community at the lower Four Mile Run through restoration, advocacy, recreation, and education. This was the second time that ARMN members participated in an event here. In the summer of 2022, ARMN held a chapter meeting at the site.

At the current event, Kurt led 20 participants on a tour of the park, ending near Mount Vernon Avenue in the Arlandria neighborhood. There, Kurt opened his storage shed and brought out equipment for participants to use in cleaning up the park.

Photo of volunteers picking up debris along Four Mile Run. — Volunteers removing debris from Four Mile Run Park. Photo by Kurt Moser.

A highlight of the Four Mile Run Park event was the attendance of many members of Our Stomping Ground. This is a local nonprofit group of adults with various developmental disabilities, and their parents, and friends. Our Stomping Ground seeks to redefine the possibilities for developmentally disabled adults, ensuring that they have the opportunity to live independent lives in integrated, supportive communities. They participate and/or sponsor numerous events throughout the year, including nature walks and clean-ups, book club meetings, and other outings. The opportunity to engage with Our Stomping Ground members at Four Mile Run Park is a reminder of the wide variety of audiences with which we can interact.

The ARMN partnership with the Alexandria Libraries (Ellen Coolidge Burke Branch and Barrett Branch) was created this year to help ARMN connect with citizens living in the Alexandria part of our region. Although the Burke and Barrett branches were already hosting their own neighborhood trash clean-ups, it was great for ARMN members to participate in this effort.

In March, the partnership had a kick-off event when ARMN member Kasha Helget, gave a Mosquitoes and Tick Management talk virtually through Alexandria’s Barrett Branch Library.

The Four Mile Run Tour and Clean-Up was the first “in person” partnership event. A third program, already scheduled for the fall, is an ARMN/Barrett Branch presentation by Elaine Mills, who will speak about native plants for apartment and condominium residents. This topic was selected because ARMN has received an extensive amount of feedback at public events from residents who don’t have yards for planting but instead live in smaller shared spaces. Elaine’s presentation will be virtual and will take place on Wednesday, September 6. Registration will be available later this summer on the Alexandria Library website. In the meantime, check out other Alexandria Library events here.

Stream Monitoring Volunteers Track the Health of Arlington’s Streams

A table covered with ice cube trays, identification sheets, and clip boards with analysis forms and pencils.

Text by Shay Pratt; photos by Colleen O’Hara

How can you tell if a stream is healthy? One of the best ways is to look at the tiny organisms that live in it. The flies, larvae, and worms found there can tell the story of a stream’s overall health, if you know how to read them.

Many types of spineless underwater organisms, known as benthic macroinvertebrates, live in the silt and pebbles of a Virginia stream bottom. Arlington County has an illustrated guide to about 20 of them found locally (adapted from the Izaak Walton League’s Virginia Save Our Streams site.)

Some are hardier than others when it comes to tolerating pollution, heavy stormwater, heat and other pressures. For example, flatworms and black flies are tougher than mayflies and caddisflies. So, you could expect to find flatworms just about anywhere you look, even in streams that aren’t very healthy, because they can tolerate tough conditions. In contrast, when you find a casemaker caddisfly, you know the stream quality must be pretty high.

By tracking the stream bug populations across time, Arlington County staff can assess the effectiveness of pollution prevention practices and identify new problems. That’s why the County’s Department of Environmental Services coordinates regular stream monitoring at 10 stream sites, including Donaldson Run, Gulf Branch, and multiple sections of Four Mile Run, with the assistance of ARMN volunteers who are trained to methodically collect and analyze macroinvertebrates.

Macroinvertebrates make for ideal test subjects because they don’t move much and they’re readily found under rocks and stones. They can be scooped up with nets, identified with magnification devices like loupes, and returned to the water.

I learned all this one day in May, when I met other ARMN members at a picnic pavilion at Lubber Run park to collect and analyze samples. We split into teams of two to collect samples at designated spots along the stream, targeting shallow, rocky areas with fast-moving, oxygen-rich water—great habitat for macroinvertebrates.

Two people stand in a stream in rubber boots. One person holds a net on a wooden pole while a sceond bends over and holds a rock in her hands. — Volunteers collecting mcroinvertebrate samples at Gulf Branch stream monitoring (analogous to the collections at Lubber Run).

My partner, Hutch Brown, a long-time volunteer who helps lead this monitoring group, dipped a long-handled net into the stream. I stood just upstream, picked up a few stones and pebbles from below the water, and gently rubbed them on all sides, loosening debris and any bugs that were living there. They floated down the water and into Hutch’s waiting net. I then scraped the silty floor with a tool shaped like a garden fork to release any macroinvertebrates living there. We carefully rinsed the contents of the net into a white plastic tub, then set off to repeat the process until our group sampled 10 total locations.

When all ten samples were collected, it was time to identify our findings. We carried our tub over to a picnic table strewn with sampling tools, ice cube trays, petri dishes, and microscopes. Using a shallow, white tray, I collected a sample of water from the collection tub and scanned its contents.

A volunteer in a sun hat bends over a white plastic tray with water from the creek holding a smaller container in her hand. — Volunteer doing first phase of sorting during Gulf Branch stream monitoring.

A volunteer uses a spoon to sort macroinvertebrates from a small dish. An ice cube tray with water sits next to the dish. — Volunteer doing first phase of sorting during Gulf Branch stream monitoring.

A table covered with ice cube trays, identification sheets, and — Identification sheets and analysis forms used to document collection results.

Within seconds, I saw movement. A faint yellow, hair-like organism only a few millimeters long twitched and spasmed. Elsewhere, a dark shape contracted and elongated on top of a water-logged maple leaf. I scooped up each critter with a pipette and plastic spoon, and transferred it to its own well in an ice cube tray. Using a loupe and a macroinvertebrate guide, I worked with the trained identifiers in our group to identify each one. Meanwhile, Stephanie Martin, another team leader, documented everything for the County.

Macroinvertebrates are easy to identify with basic magnification and practice. Most stream bugs have telltale physical characteristics. Mayflies exhibit 2-3 hair-like tails. Flatworms have triangular heads and a pronounced, cross-eyed look. Black flies look like mini-bowling pins, with a sucker on one end that they use to attach to surfaces. Our group made quick work identifying over 100 organisms.

In our survey of Lubber Run, we found mostly organisms that can tolerate poor to fair conditions—flatworms, black flies, a few aquatic worms, and lots and lots of midges. We also found some small minnow mayflies, which are much less tolerant of pollution, and indicate good riffle habitat found in the monitoring reach. These results confirmed that Lubber Run, like many of Arlington’s streams, is overall in fair condition.

Of all of Arlington’s stream monitoring sites, Lubber Run’s watershed has the most hard surfaces, with about half of its land covered with roads, roofs, parking lots, and other impervious surfaces. When a stream’s drainage area is more than 10% impervious cover, it is considered to be impacted as an urban stream. Arlington’s streams reached that development milestone decades ago, as land that once absorbed rainwater was developed. Over 40 percent of Arlington land is impervious to water, so the streams channel a lot of water after storms. That stormwater scours out the homes of many invertebrates and often carries pollution and sediment that impact habitat.

There are no easy fixes for these problems, but Arlington County is paying attention to the health of its streams—working to install Green Street rain gardens to capture rain runoff, reduce stream erosion, and educate the community about how we can all help prevent stream pollution. Data collected by volunteer stream monitors can make the case for intervention and track changes over time.

Lily Whitesell, who coordinates stream monitoring as Arlington County’s Stormwater Outreach Specialist, said the ongoing work has documented seasonal patterns (life cycles of the macro invertebrates) and patterns of disturbance and recovery. Longer term trends have been stable over time.

“We want to help our streams be as healthy as they can be, given our urban watersheds,” Whitesell said. “It’s good for our benthic macroinvertebrates, for the fish that rely on them, for the overall diversity of our local aquatic and terrestrial ecological communities, for the people that enjoy, appreciate, and rely on our streams, the Potomac River, and Chesapeake Bay.”

For more information:

Read more about stream monitoring in Arlington County
Watch this video on macroinvertebrates in Arlington streams
Learn about how to prevent and report stream pollution
Get involved: contact Lily Whitesell, Stormwater Outreach Specialist to become a volunteer

Teaching Children About Nature Through the Magic of a Loupe

Text and photos by Eric Weyer

Nature is a never-ending source of wonder, offering an abundance of intricate details, some so tiny they can barely be seen with the naked eye. That makes “loupes” (or hand lenses) one of the most important tools in any naturalist’s arsenal.

During a recent training exercise for ARMN volunteers learning to teach young people about nature, I also saw what a powerful tool a loupe can be in a child’s hand.

A loupe is essentially a super magnifying glass that allows users to see small details up close and personal. Before I became a member of the Arlington Regional Master Naturalists in 2021, I didn’t know what a loupe was.

My first use of loupes was practical. As a volunteer stream monitor for Arlington County, I used them to identify the macroinvertebrates that live in our streams. Telling the difference between broad-winged and narrow-winged damselfly larvae is tricky without magnification.

However, it wasn’t until early April, during a training with Bobbi Farley and Serenella Linares, that I truly learned what a world of wonder loupes can open.

The goal was to teach volunteers with an ARMN after-school program called “Nature Core Outdoors” some tips and tricks for interpreting nature to children. Nature Core is a partnership between ARMN and the Arlington Housing Corporation (AHC Inc.) that aims to introduce elementary-age residents in AHC’s after-school program to nature. The program is led by Alison Sheahan and Romana Campos, and includes volunteers from ARMN and other local nature groups including Virginia’s Extension Master Gardeners and Tree Stewards of Arlington and Alexandria.

Volunteers commit to teaching six weekly one-hour after-school sessions, with the goal of sparking joy and wonder in the children for the nature living in their own backyard.

Bobbi, a naturalist at Long Branch Nature Center in Arlington, kicked off the session by describing an insect lesson she teaches to kids. She stopped throughout to explain techniques she uses to keep the children’s attention, such as call-and-response shouts or claps. She showed how to engage children with different learning styles by varying her questioning techniques—asking for a shout or a raised hand or directing a question to a specific person. And she shared some silly, interesting facts. (I believe poop came up at least once.)

Serenella, a Park Naturalist at Mt. Rainier Nature Center in Maryland, then took us outside for another example lesson. She gave us a set of loupes and told us we had five minutes to find something interesting to discuss with the group.

Being an enterprising fellow, I took out my phone and snapped a few pictures of a beetle crawling on an American Hornbeam (Carpinus carolinia) leaf. Others wandered around the area outside the nature center, looking at flowers, leaves, even the lichens growing on a branch by the trail.

After five minutes were up, I was the first to show my photo to the group. Everybody oohed and ahhed when they noticed the little bits of pollen stuck to the beetle’s elytra (forewings) and legs, an example of pollination up close! We shared a few other findings, then reluctantly returned our loupes to Serenella and headed back inside, where she used this experience to teach us some more child-focused interpretation and group management techniques.

I was inspired by Serenella’s lesson. If this activity evoked such joy in us adults, I could only imagine the wonder it would create with our group of around 20 eager-to-learn 8-to-10-year-olds at the Woodbury Park Apartments in Arlington.

In our first lesson with them, we had spent a long time looking at seeds with only our eyes. I knew how amazing those seeds would look under 30x magnification!

At the next class, I showed up with 32 loupes I had purchased online. From the moment I told the students, “You can look through these at small things like the seeds we observed last week,” they started running off in search of cool things to look at. They were so entranced that I, along with the other Woodbury Park volunteers Barbara Raizen, Eileen Miller, and Liz Macklin, decided to forget about our planned lesson and join them.

We spent about 15 minutes marveling at how different all the little things we see in everyday life look when blown up. The first thing we studied was a dandelion, noticing how its deep yellow bracts looked like those on other flowers nearby. Then we looked at some leaf galls. We decided that the teardrop-shaped green and purple galls were “nature’s Hershey Kisses.” The others we couldn’t quite agree on names for—alien spaceships and Alice in Wonderland were the top votes.

Upclose photo of a leaf gall — Dandelion flower as seen through a loupe.

Later we gave up our loupes for our final event, a bird scavenger hunt. Liz highlighted some common birds in the area and we split into small groups to start our search, stopping every fifteen seconds or so to observe something new. Whether a bird or a bug, it was always a perfect thing to look at with our loupes. We even found a skull that we were able to identify as a rabbit’s skull.

At the end of the lesson, we could see the excitement in the children’s faces as they talked about everything they had discovered. Seeing their enthusiasm made us all feel like we had accomplished something meaningful, thanks to fabulous leaders and teachers—and a few dozen loupes.