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Hiking Lincoln Peak © K.P. McFarland

Field Guide to June 2022

Spring ephemerals have begun to fade, and baby critters abound—June has arrived, and summer is hot on its heels. Across the landscape, wildlife dramas large and small unfold. Warm breezes carry away the last memories of winter frost. June has much to offer, from tapeworms using mind-control to Eastern Cottonwoods shedding their downy seeds. Start the month off here.

By Vermont Center for Ecostudies June 6, 2022
12495, , large (59), , , image/jpeg,, 852, 802, Array, Array © Jesse Rorabaugh
Doubtful Acorn Ant (Temnothorax ambiguus) © Jesse Rorabaugh
12497, , large (61), , , image/jpeg,, 1024, 896, Array, Array © Isaac Winkler
Temnothorax nest in a gall © Isaac Winkler

What is in an Ungerminated Acorn?

By Julia Pupko

Can you imagine your entire neighborhood being controlled by a tapeworm? This isn’t too hard to picture for Temnothorax ants. Ants within this genus average 2 to 4 mm in length and build their colonies in small cavities, including hollowed-out acorns or hickory nuts, in branches, under rocks, etc. With around 400 species worldwide and at least 50 species in North America, New England is home to at least six species: Temnothorax ambiguus, T. curvispinosus, T. longispinosus, T. texanus, T. schaumi, and T. pilagens. Several of these species inhabit acorns, selecting hollowed-out nuts with a high internal surface area to build their nest. They ensure their queen and brood are located in central chambers, moving them towards the top of the acorn if lower chambers become infected with microbes or other parasites or if the top of the acorn is warmer, which stimulates faster brood growth.

But let’s back up for a minute and sketch out how we arrived at the hive-mind acorn. During June, oak trees have just finished blooming, and their leaves are still unfurling. For oaks in the white oak group, such as Bur Oak (Quercus macrocarpa) and White Oak (Quercus alba), acorns will fully develop between the end of summer and the beginning of fall. Meanwhile, acorns on oaks in the red oak group—like Northern Red Oak (Quercus rubra)—take two seasons to develop. They will not reach full maturity until the end of the following summer or fall. Some of these acorns fall prey to various parasites or fungi, which hollow out the center of the acorn. Once the initial inhabitants have abandoned the acorn, Temnothorax ants may move in.

During the winter, Temnothorax ants typically congregate in a central nest, grouping together in an attempt to stay warm enough to survive the winter. Once spring and summer roll around, the colony typically fractures into several nest sites. Worker ants set out to find new sites, recruiting other workers to visit promising locations.

At the same time, other workers are tasked with providing food to the brood and queen, some of which are bird feces. In a study conducted in Germany, Temnothorax ants that ate bird feces laden with certain tapeworms became hosts, sometimes for up to 70 individual tapeworms. The tapeworms increase the lifespan of their host, sometimes for decades, keeping their appearance youthful and elevating them in status amongst the colony. Infected ants are fed, pampered, and moved around by the uninfected workers while no longer required to do any tasks themselves. This strains the rest of the colony, decreasing the lifespan of uninfected workers trying to care for the queen and the infected workers simultaneously.

The tapeworms may only infect a few individuals in a colony of up to several hundred. Still, they can control the actions of the entire colony by causing others to care for the infected individuals, which may benefit the tapeworms in the long haul. The tapeworm needs to get back into a bird to complete its life cycle, and extending the life of these infected workers and causing them to sit around in the nest ensures that they will live to be eaten by a bird. When the acorns are opened, infected ants do not attempt to move the brood or vacate the nest; they simply sit and stare upwards, unmoving.

If mind-controlling tapeworms aren’t enough to handle, Temnothorax ants living in acorns occasionally have to worry about attacks from other Temnothorax ants. T. pilagens, or the Pillage Ant (one of the species found in Vermont), is another acorn-dwelling Temnothorax species. However, this species raids other Temnothorax ant nests—particularly T. longispinosus and T. ambiguus—stealing brood and enslaving adults in their own nests. Raids are often accomplished by a single scout or group of up to 4 ants. The ant colonies they forcibly take workers from often do not recognize an enemy in their midst, indicating that T. pilagens may exude a chemical that masks their presence as an intruder. If the invaded ants resist, T. pilagens uses a powerful stinger to paralyze and kill those putting up a fight.

As you walk through hardwood or mixed forests containing oaks or hickories this June, slow down to check out the acorns or hickory nuts on the ground. You may just find a stream of tiny ants scurrying to and from their nest, searching for food, new nest sites, or other ant colonies.

12499, , large (27), , , image/jpeg,, 768, 1024, Array, Array © Spencer Hardy
Dark-legged Yellow Loosestrife Bee (Macropis nuda) © Spencer Hardy
12500, , large (28), , , image/jpeg,, 768, 1024, Array, Array © Spencer Hardy
Macropis patellata © Spencer Hardy
12501, , large (63), , , image/jpeg,, 768, 1024, Array, Array © Spencer Hardy
Fringed Loosestrife (Lysimachia ciliata) © Spencer Hardy

Bees of the Month: Macropis

By Spencer Hardy

With summer in full swing, June can be an overwhelming month for any insect enthusiast. Tons of cool bees are out and about this month, but one genus stands out for its unique natural history and conservation status. The oil-collecting bees (genus Macropis) are the only bees in the area known to collect plant oils to feed to their offspring. These oils only come from a few species of loosestrifes (genus Lysimachia), which are critical to the survival and reproduction of these bees. Not to be confused with the unrelated Purple Loosestrife (Lythrum salicaria), at least nine different Lysimachia exist in Vermont, but only a few species are visited by these bees. Starting in early June, Whorled Loosestrife (Lysimachia quadrifolia) is found primarily in hot, dry sites such as powerline right-of-ways and open oak forests. Later in June, Fringed Loosestrife (Lysimachia ciliata) flowers open in wetter areas, often along rivers and roadside ditches. Swamp Candles (Lysimachia terrestris) are more of a July flower, found in wet fields and adjacent to other wetlands.

Despite these relatively widespread flowers, oil-collecting bees can be frustratingly hard to find. They are currently a species of conservation concern due to apparent declines. One of the three species in the northeast, the Patellar Oil-collecting Bee (Macropis patellata), has only been found at a few sites in the world in the past 50 years—including South Burlington! The other two species are the Dark-legged Yellow Loosestrife Bee (Macropis nuda), which seems fairly widespread in Vermont, and Macropis ciliata, the most common of the three species in Massachusetts but not yet recorded in Vermont.

All three species can probably be identified from high-resolution photos and are good targets for community naturalists, especially if you can locate a patch of Lysimachia in your neighborhood. Check out our Macropis page for more photos and links to a preview of our new and improved species accounts!

If you can’t locate Lysimachia, other plants to seek out this month include Golden Alexander, Viper’s Bugloss, Virginia Waterleaf, He-Huckleberry, and shrubby Dogwoods.

Cottonwood Seeds © John Lillis
Cottonwood Seeds © John Lillis

Cotton Storm

By Julia Pupko

In a groggy delirium, I struggled to pull myself from bed one overcast June morning. To my horror, clouds of white fluff were drifting past my window. It felt surreal—snow in June? But as I woke up and poked my head out the door into the warm breeze, I realized it was a storm of cotton-like seeds drifting on the wind.

Most of these flying fibers come from Eastern Cottonwoods (Populus deltoides). Larger individuals may produce up to 48 million seeds on a good year! Their seeds are tiny, only a few mm in length, surrounded by a halo of fluff. But don’t let this fool you—most seeds perish due to lack of moisture, fungus, or herbivory. Eastern Cottonwoods are a relatively common species with a wide range, spanning most of the United States, east of the Rocky Mountains. Individuals can grow to be over 100 feet tall, with a diameter of up to five feet at breast height. Leaves are highly nutrient-rich and are a favorite food of many species, including field mice, rabbits, deer, and domestic livestock. Some songbirds, such as grosbeaks, eat the seeds, but the leaves and the bark are the usual go-to for most species that utilize Cottonwood trees. Keep your eyes out for these beautiful trees in floodplains and along water bodies, and be sure to report your observations to iNaturalist.

12509, , large (30), , , image/jpeg,, 1024, 683, Array, Array © Spencer Hardy
Colorado Potato Beetle (Leptinotarsa decemlineata) © Spencer Hardy
12508, , large (31), , , image/jpeg,, 1024, 683, Array, Array © Spencer Hardy
Colorado Potato Beetle (Leptinotarsa decemlineata) © Spencer Hardy

Colorado Potato Beetles

By Spencer Hardy

If you’ve ever grown potatoes, you probably despise the Colorado Potato Beetle (Leptinotarsa decemlineata). Both larvae and adults are voracious eaters and one of the most destructive garden pests around. But this hasn’t always been the case; they’ve only been eating potatoes for roughly 160 years. These giant, showy beetles evolved from eating Buffalo-Bur (Solanum rostratum) in the Rocky Mountains. They weren’t detected on potatoes (Solanum tuberosum) until 1859, after which they spread across the Eastern US at an estimated 140km per year!

Another closely related species, the False Potato Beetle (Leptinotarsa juncta), is found sporadically in Vermont. This one doesn’t bother potatoes, instead preferring Carolina Horsenettle (Solanum carolinense), though occasionally eating tomatillos and ground cherries (genus Physalis). The dynamic range and host preferences for this genus and climate-driven changes in phenology make them great candidates for monitoring with community-science networks like iNaturalist, especially when observations are well annotated.

12502, , fawn-over-the-fawn-lt3, , , image/jpeg,, 1920, 1273, Array, Array © Haanala76 - Public Domain Photos
Fawn on forest floor © Haanala76 - Public Domain Photos
12503, , 2552934944_0533f7dbdf_c, , , image/jpeg,, 800, 536, Array, Array © Becky McCray
Fawn © Becky McCray


By Julia Pupko

During June (and for much of the summer), I spend my time striding through fields and forests, sweep netting for lady beetles. It is essential to watch where I am stepping this month. While irate bird parents typically give a good heads up when I venture too close to their nest, other species do not move a muscle until you are about to step directly on them. Take White-tailed Deer fawns, for example; just two days ago, I came within a step of trampling a fawn before realizing the little one was there.

Around June, many White-tailed Deer (Odocoileus virginianus) begin to give birth. For the first few weeks after birth, fawns are relatively helpless and don’t have the strength to keep up with their mothers while they forage or outrun predators. As a result, mother deer leave their young for up to four hours but are usually close at hand, just in case their baby needs them. But how do these helpless babies survive?

Fawns’ spotted coats camouflage them amongst the grasses, forest floor, or shrubs where their mothers leave them, resembling dappled sunlight on the forest floor. This pattern helps break up young deer’s silhouettes, especially since most mammals do not see in color the way we do. Fawns appear in shades of gray and white to mammalian predators, effectively blending into their surroundings as they lie flat and unmoving on the ground. Young deer can be hard to spot, even to those who see in color. Additionally, fawns have almost no scent, so a predator can walk right past them without noticing, as long as they do not move. This gives their mother time to distract the predator, leading it away.

If you find a fawn, do not touch or move them. Leave the baby where it is without disturbing it, so its mother can return to her child just where she left them.

12515, , flower-copy_390x540_acf_cropped, , , image/jpeg,, 390, 540, Array, Array © lightbed on iNaturalist
Narrow-leaved Blue-eyed Grass (Sisyrinchium angustifolium) © lightbed on iNaturalist
12505, , large (29), , , image/jpeg,, 768, 1024, Array, Array © karuquebec on iNaturalist
Black Locust Flowers (Robinia pseudoacacia) © karuquebec on iNaturalist
12506, , large (64), , , image/jpeg,, 500, 667, Array, Array © Nonbinary-Naturalist on iNaturalist
Common Milkweed (Asclepias syriaca) © Nonbinary-Naturalist on iNaturalist

Painted June

By Julia Pupko

June is an explosion of color from start to finish. Although our spring ephemeral flowers have passed, there are plenty of fresh blooms for pollinators and your eyes to enjoy. Here are some flowers to keep a watch for.

Blue-eyed Grasses
In Vermont, we have four species of blue-eyed grasses: Narrow-leaved (Sisyrinchium angustifolium), Eastern (S. atlanticum), Strict (S. montanum), and Needle-tipped (S. mucronatum). These species have delicate blue to purple flowers with six petals. Narrow-leaved and Eastern Blue-eyed Grasses can be found in meadows, fields, and wetland areas, while Strict and Needle-tipped Blue-eyed Grasses can be found at forest edges or in open spaces such as meadows and fields. blue-eyed grasses are not true grasses but are members of the Iris family. These plants close their blooms at night to preserve nectar and pollen for the droves of bees, syrphid flies, butterflies, and other pollinators that visit their flowers.

Black Locust
While most of our trees have already flowered, Black Locust (Robinia pseudoacacia) trees are just getting started. Their fragrant, white flowers hang down in groups attached to a long stem. Black Locusts are actually considered invasive in Vermont because they are originally a more southern species. However, they fix nitrogen, providing food for other plants, and their flowers provide food for pollinators and people alike. Yes—their flowers are edible and contain lots of antioxidants! You can eat them raw, cook them into pancakes, or make yourself a cup of tea. Just be careful; leaves, stems, and other parts of the plant are toxic, so do your research before you start snacking.

As June progresses, the milkweeds (Asclepias species) will begin to bloom. This is likely a familiar genus and are the chosen plants of Monarch butterflies. While Monarchs lay eggs on all nine milkweed species, they prefer Common (A. syriaca) and Swamp (A. incarnata) Milkweeds. Watch for their clustered white to pink or orange flowers erupting from the top of a single stem that has paired, opposite leaves. If you spot some Milkweed, be sure to check for Monarch caterpillars, adult butterflies, Ursine Spurleg Lady Beetles, and other insects. Don’t forget to report your sightings on iNaturalist!

Northern Long-eared Bat (<i>Myotis septentrionalis</i>) © Jason Ksepka
Northern Long-eared Bat (Myotis septentrionalis) © Jason Ksepka

Baby Bats

By Julia Pupko

In Vermont, we have eight species of bats. One of them is the Northern Long-eared Bat (Myotis septentrionalis). In the spring, females either move to their own roost or form small maternity colonies of up to 30 bats, giving birth to a single pup in June. However, Northern Long-eared Bats actually begin their reproductive cycle in the fall. Females store the males’ sperm until April or May when they emerge from hibernation.

Pups are pretty helpless when they are first born. They are hairless and flightless and spend their first month of life nursing and waiting at the roost while their mothers go out to feed at night. At four to six weeks, young Northern Long-eared Bats begin flying and exploring on their own, and maternity colonies break up soon after. Young typically do not start reproducing until their second year of life.

Females typically use large trees as roosts in the spring and summer, hiding in crevices or under the bark. They prefer larger maple, ash, or oak trees in older forests with complex vertical structures. Occasionally, they may roost in human structures. In the winter, these bats roost in caves or deep crevices.

Northern Long-eared Bats are currently listed as threatened on the federal Endangered Species List. In March 2022, US Fish & Wildlife Service proposed a new rule to reclassify these bats as endangered due to the ongoing impacts of white-nose syndrome. A final decision will be announced in November 2022. Meanwhile, in Vermont, Northern Long-eared Bats are already listed as endangered.

So, if you happen to encounter a Northern Long-eared (or other) Bat roost this summer, please give them space. If you have issues with bats roosting in human structures, find an abandoned pup, or want to learn more about Vermont’s bats, please visit Vermont Fish & Wildlife Department’s website to learn more.

Comments (2)

  1. Veer Frost says:

    Hello, I would like to leave a query about the Fringed Loosestrife mentioned in this post. This beautiful wildflower grew right along a long driveway right above Stone Creek in Fairfax for the years I housesat there, off Shepardson Hollow Rd. I fell in love with its rather elegant down-facing flowering habit and tried bringing a bit home to NEK but while it sort of grew and flowered it did not flourish, the leaves twisted etc., and each year I pull out the little ones, just one or two this year. Reading that it’s not in Vermont means ?? not sure, that I mis-identified it, perhaps not ciliata but another species is here? My 3 wildflower books all called it for Fringed!

    Sorry I am not on social media so am leaving this note here. Thank you! Veer Frost

  2. Veer Frost says:

    Ok have been advised I misread the article, there are several Fringed Loosestrife species in VT! And the one I used to love is common enough : ).

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