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Summer evening in the Green Mountains. © K.P. McFarland

Field Guide to July 2021

The dawn bird chorus now fades from northern woodlands as the hills erupt in the sparkle and drama of summer insects. Here are some July happenings to kick off your month.

By Vermont Center for Ecostudies July 1, 2021
11471, , original (1), , , image/jpeg,, 1365, 2048, Array, Array © K.P. McFarland
Genus Photuris © K.P. McFarland
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Winter Firefly (Ellychnia corrusca) © K.P. McFarland

Night-time Light Shows

By Julia Pupko

One of my summer favorites is watching the mesmerizing light shows of fireflies (Family Lampyridae) at night. As I started looking into fireflies, I began to realize how little I knew about them (isn’t that always the way learning goes?). Worldwide, there are over 2,000 species of firefly, with between 150 and 200 of these species found in North America. So far, 8 species of firefly have been recorded in Vermont on iNaturalist, but it is still unclear exactly how many species reside in New England, or in Vermont, for that matter.

Fireflies light up at night to attract mates. Each species has a specific flashing pattern used to attract a mate of the same species. To light up, a chemical reaction takes place—a molecule called luciferin is broken down by the enzyme luciferase in the presence of oxygen and magnesium within the light-emitting organ of the firefly. While all firefly species can light up when they are in their larval stage, only some fireflies retain the ability as adults. Some fireflies are diurnal (active during the day) so they have no need to light up and instead use pheromones to communicate.

A fun fact about fireflies is that they spend most of their lives in their larval state, living up to two years before metamorphosing into adults, where they usually only live a few weeks. Firefly larvae are predatory, hunting slugs, worms, millipedes, and other such food sources. The females of one firefly group, called Photuris, actually lure in males of other firefly species by mimicking their flash patterns to turn them into dinner! This allows the female Photuris to absorb the toxins found in the male, called lucibufagins, and use them as a chemical defense to protect her eggs.

Sadly, light pollution seems to be contributing to firefly declines. Outdoor lights inhibit potential mates from seeing each other’s flashes, thereby inadvertently making mating challenging or impossible for some populations. Climate change, pesticide use, and habitat loss may be driving firefly decline as well.

11487, , original-1-1_580x400_acf_cropped, , , image/jpeg,, 580, 400, Array, Array © Spencer Hardy
Eastern Calliopsis Bee (Calliopsis andreniformis) © Spencer Hardy
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Calliopsis Cuckoo Nomad Bee (Holcopasites calliopsidis) © Spencer Hardy

A Tiny Bee Circus on the Ground Near You

By Spencer Hardy

One of Vermont’s weirdest bees could easily be in your backyard right now and you might never know it. The Eastern Calliopsis Bee (Calliopsis andreniformis) looks like something out of a circus, but since it could hide behind a grain of rice, few people notice them. To find them, one must first locate a disturbed area with ample bare soil—ball fields, construction sites, town greens, dirt parking lots, etc. Next, find some flowers growing low to the ground and lie down. This bee seems to have a preference for tiny legumes such as Black Medick (Medicago lupulina), but will visit a wide variety of plants if it doesn’t have to be far off the ground. Also look for the males sunning themselves on south facing rocks and dirt banks. Though you might get puzzled looks from other humans, chances are you won’t be the only one looking for this bee. The Calliopsis Cuckoo Nomad Bee (Holcopasites calliopsidis) is an equally small and stunning creature that is an obligate kleptoparasite of Calliopsis Bees.

You can learn more about these bees at the Vermont Wild Bee Survey.

Male Monarch on Common Milkweed. © K.P. McFarland
Male Monarch on Common Milkweed. © K.P. McFarland

Making More Monarchs

By Kent McFarland

Monarchs are famous for their amazing fall migration, flying thousands of miles from the northern U.S. and Canada south to winter in the mountains in central Mexico each year. The last generation of monarchs, those that will ultimately migrate, are produced in July—perhaps in a milkweed patch near you.

Arriving as early as mid-May in some years in the Northeast, monarchs probably have two generations here during the summer before migrating southward each fall. Some years, it’s impossible to find caterpillars of the second generation in July and August, while in other years (last year was above average), they seem to be plentiful. I have noticed that in late July and August, the place to find hungry caterpillars is on younger and more succulent milkweed. And in late summer, the only places you find this are areas that were mowed in early July.

Research in New York found that manipulating Common Milkweed phenology through mowing could be used to increase monarch productivity in late July and August. Biologists mowed strips in fields at the beginning of July, late July, and mid-August. They compared these to unmowed control areas by carefully monitoring milkweed growth and counting monarch eggs and caterpillars. As they predicted, mowing fields with Common Milkweed extended the monarchs’ breeding season and increased overall monarch reproduction.

The authors wrote, “We found mowing on July 1 and 24 spurred the regrowth of milkweed and sustained a more continuously suitable habitat for monarch oviposition and larval development than the control. Mowing on August 17 proved too late for recovery of the milkweeds. Significantly more eggs were laid on the fresh resprouted milkweeds than on the older and taller control plants. In the strips mowed on July 1, peak egg densities occurred in late July; in the strips mowed in late July, peak egg densities occurred in early to mid August.” But it is important to remember that if you mow for monarchs, only mow patches or some strips so that older growth and other flowering plants will be available for adults and other pollinators.

Adult monarchs need sources of nectar to nourish them throughout the entire growing season and during migration. Try to include a variety of native flowering species with different bloom times to provide monarchs with the food they need to reproduce in the spring and summer and to migrate in the fall. Offering a wide array of native nectar plants will attract not only monarchs but other butterflies and pollinators to your habitat all season long. You can get a list of monarch nectar plants for your region from Xerces Society’s Monarch Nectar Guides.

Join the 2021 International Monarch Monitoring Blitz July 23 – August 1

In the last two decades, the eastern monarch population has declined by 80%. We still have a lot to learn about monarchs in order to protect them, and you can help! From July 23 to August 1, butterfly watchers across Vermont (and all of North America) are invited to take part in the International Monarch Monitoring Blitz to help provide a valuable snapshot of monarch population status across their late summer range. Mission Monarch is a community science program to gather data on Monarch and Milkweed distribution and abundance each year during the breeding season. Participants find milkweedlook for Monarchs and share their observations with us on the Mission Monarch website.

Participation is simple! Just complete one or more missions during the Blitz between July 23 through August 1 and add your observations to Mission Monarch. Conducting a mission is easy and fun! From backyards to mountain meadows, all you need is a place where milkweed is growing. Learn more at

American Goldfinch © Marv Elliott (CC-BY-NC)
American Goldfinch © Marv Elliott (CC-BY-NC)

Mid-summer Fluffs

By Julia Pupko

In late May, I was strolling along the White River and noticed a family of geese, with goslings already well on their way to being full-blown adults. While the size of these goslings was rather shocking, the fact that early-returning migrants and resident birds had already started raising their young was not.

In Vermont, many bird species nest and raise their young between May and June, often utilizing the abundance of insects and other protein-rich prey to feed their little ones. By the end of July, most birds have totally finished raising their young, and some are already preparing to journey south. However, this does not hold true for all species. The American Goldfinch does not begin nesting until July, with peak nesting occurring between late July and early August. This is because the American Goldfinch eats an entirely vegetarian diet all year and raises their young the same way. They wait until late-summer to ensure there are plenty of seeds to feed their young and use the fluff from milkweed, thistles, and other plants to build their nests. These plants don’t go to seed (and therefore don’t release the fluff that assists with their seed dispersal) until mid-summer.

You can find American Goldfinches in shrubby areas or fields surrounded by shrubs and trees. Just make sure to share your observations to Vermont eBird!

1611, , ad ch wantatiquet joanne bridges JSB_July 20, 2014DSC_3754, Loon family on Wantastiquet Pond in Weston, VT.  Photo by Joanne Bridges, , image/jpeg,, 1000, 667, Array, Array © Joanne Bridges
Loon family on Wantastiquet Pond in Weston, VT. © Joanne Bridges
11477, , chick-and-ad-profile-6-wk-janet-steward_580x400_acf_cropped, , , image/jpeg,, 580, 400, Array, Array © Janet Steward
A six week old Common Loon chick with an adult. © Janet Steward

A Family of Loons on a Lake Near You

By Kent McFarland

Male and female Common Loons both tend to their young, feeding insects and minnows at first and larger fish later. Although loons will eat almost any fish they catch, perch are a favorite food. A loon’s average dive length is 35-40 seconds. Most fish are swallowed underwater with only the occasional larger fish brought to the surface. In a loon’s gizzard, which contains small stones, powerful enzymes and stomach acids help to digest the fish—bones included.

Adults guard their chicks during this period. Males might “yodel” at intruder loons or boaters who come too close. If intruder loons are present, chicks are often hidden near shore. The parents will also move the family to areas with less wind and wave action.

Common Loons will also eat live bait and lures from anglers. We routinely encounter loons tangled in fishing line, and loons that have ingested fishing line and bait. The results can often be fatal. Please “reel in” when loons are diving nearby and avoid using lead fishing gear of any kind.

Join the 38th Annual Vermont LoonWatch on July 17

Survey a lake for one hour on the third Saturday of July each year. If you’ve got time, survey a few lakes. On this single day, we cover more than 130 lakes and ponds statewide each year. It’s the single most effective way for VCE to document and track breeding loons across the state. To get an assignment for the annual LoonWatch, contact our loon biologist, Eric Hanson. Eric keeps a list of lakes where we need volunteers.

Here’s a map of the latest Common Loon sightings in Vermont from Vermont eBird, a project of the Vermont Atlas of Life. If you see loons, please report them to Vermont eBird and help us track their populations.

11463, , lupine, , , image/jpeg,, 802, 1024, Array, Array © Nathaniel Sharp
Large-leaf Lupine (Lupinus polyphyllus) © Nathaniel Sharp
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Bluestem Goldenrod (Solidago caesia) © Nathaniel Sharp

July Jewels

By Julia Pupko

While many of our wildflowers bloom between May and June, there are still lots of beautiful wildflowers that you can find this month across forests, mountaintops, fields, and wetlands. Here are just a few to keep an eye out for (and don’t forget to submit observations to the Vermont Atlas of Life on iNaturalist!).

Field Species:

A species already in bloom that will continue into July is Sundial Lupine (Lupine perennis). This species has palmately-compound (hand-like) leaves and a tall stem displaying its clusters of purple, pink, or white flowers. Wild Lupine was originally thought to deplete, or “wolf,” the soil (thus its name), but it actually enhances the soil’s nitrogen content through its ability to fix atmospheric nitrogen. July is also the month that Goldenrods (Solidago sp.) start blooming. There are over 100 different species, with 25 species recorded on the New England Native Plant Trust GoBotany site. This is an important species for many pollinators, especially towards the end of the summer.

11465, , large (1), , , image/jpeg,, 768, 1024, Array, Array © Nathaniel Sharp
Harebell (Campanula rotundifolia) © Nathaniel Sharp
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Diapensia (Diapensia lapponica) © K.P. McFarland

Alpine Species:

Harebell or Scotch Bellflower (Campanula rotundifolia) can be found at low and high elevations. This plant has simple, crescent-shaped leaves and bell-shaped blue to purple flowers. The roots have been used in traditional herbal medicine for earaches and heart ailments. This species can be found around the northern hemisphere, which is why one of its common names is Scotch Bellflower, even though it is native in Vermont. An alpine-only species that you can find blooming in July (begins blooming in June) is Diapensia (Diapensia lapponica). This species is long-lived (some cushions have been estimated to be over 800 years old!) and found in northeastern North America, Iceland, Greenland, Scotland, and Russia. Diapensia is well-adapted to the cold, alpine climates it lives in, and has the ability to trap solar heat within its leaves and cushion structure so effectively that the insides of cushions can be up to 8 degrees Celsius warmer than the ambient air temperature.

11467, , large (1), , , image/jpeg,, 768, 1024, Array, Array © K.P. McFarland
Spotted Joe-Pye Weed (Eutrochium maculatum) © K.P. McFarland
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Swamp Milkweed (Asclepias incarnata) © Nathaniel Sharp

Wetland Species:

Spotted Joe-Pye Weed (Eutrochium maculatum) is a perennial forb that can be found in wetlands, swamps, and wet, poorly-drained areas. It begins flowering in July and continues to flower through September. Flowers are purple to light pink in a flat-topped cluster at the top of the plant. Leaves are whorled around the stem. Another wetland species that will be blooming in July is the Marsh Milkweed (Asclepias incarnata). Like the Common Milkweed (which will also be blooming in July), Marsh Milkweed is important for Monarch Butterflies. The pink to purple inflorescences (flower heads) are edible, and many parts of the plant have been used medicinally for a number of different ailments.

11469, , original (1), , , image/jpeg,, 1536, 2048, Array, Array © Nathaniel Sharp
Whorled Wood Aster (Oclemena acuminata) © Nathaniel Sharp
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Canadian Bunchberry (Cornus canadensis) © Nathaniel Sharp

Woodland Species:

Whorled Wood Aster (Oclemena acuminata) is a common species along hiking trails. It’s simple, oblong, serrated leaves appear to be whorled around the step and it has thin, white flower petals with a yellow and orange center. Canada Bunchberry (Cornus canadensis) is another species you can find blooming in July. It is a small perennial plant that can often be found in clusters, as it spreads with underground stems. It has 4 to 6 leaves and white flowers with 4 petals, which give way to bright red berries later in the summer. It is one of the only herbaceous species in the Dogwood (Cornus) group (most species in this group are shrubs or trees).

Primrose Moths in and on their favorite flower. © Bryan Pfeiffer
Primrose Moths in and on their favorite flower. © Bryan Pfeiffer

The Primrose Ruse

Like most of you. Naturalist Bryan Pfeiffer likes to spend his summer leisure time contemplating the tongue of the Primrose Moth. Okay, it’s not exactly a tongue. Butterflies and moths have a straw-like proboscis that they coil like a watch spring and unfurl to suck nectar from flowers (and essential minerals from mud or scat). The Primrose Moth’s proboscis is about half the length of its body. That anatomy alone might be enough to generate interest in this insect. But now consider that the Primrose Moth is Pepto-Bismol pink with a lemony margin at the tips of its wings. In that pink presentation and probing proboscis, the Primrose Moth offers us a lesson in form, function and evolution. Read more on Bryan’s blog.

5612, , OR moth crew_KPMcFarland, Co-hosts Kent McFarland and Sara Zahendra are joined by JoAnn Russo, naturalist and moth expert, to watch backyard moths. , , image/jpeg,, 2500, 1875, Array, Array
Kent McFarland, Sara Zahendra, and JoAnn Russo mothing in the backyard.
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Moth watching on a warm night. The black light is an old ‘bug zapper’ that has had the zapping parts removed.

Join the Vermont Moth Blitz During National Moth Week July 17 – 25

National Moth Week celebrates the beauty, life cycles, and habitats of moths. “Moth-ers” of all ages and abilities are encouraged to learn about, observe, and document moths in their backyards, parks, and neighborhoods. Held worldwide during the last full week of July, National Moth Week offers everyone, everywhere a unique opportunity to become a citizen scientist and contribute information about moths. Through partnerships with major online biological data depositories, participants can help map moth distribution and provide needed information on other life history aspects around the globe. Here at VCE, we map moth distribution throughout the year for our Vermont Moth Atlas through data collection on the Vermont Atlas of Life on iNaturalist, and we celebrate the week with our annual Vermont Moth Blitz. Turn on your porch light, photograph moths, and add them to our project. It’s easy and fun!

How many moth species can we find during moth week?
We encourage you to add your photographs of moths, too. Thanks to the tireless efforts of both professional and amateur Lepidopterists since the 1995 landmark publication Moths and Butterflies of Vermont: A Faunal Checklist, nearly 400 new moth species have been found in Vermont. Preliminary results show that there are now over 2,200 species of moths known from Vermont. And, there are likely many more awaiting our discovery.

Since 2013, professional biologists and naturalists have contributed moth observations to the Vermont Atlas of Life on iNaturalist. Many of us turn on special lights in our backyards on summer nights to find hundreds of moths and other insects gathering on our sheets, hunt fields and forest for day-flying moths, and place rotten fruit bait out to attract other moths. Many of these moths can be identified from good photographs (although some are impossible without dissection and examination under a microscope). With today’s amazing digital photography technology, coupled with the newer Peterson’s Field Guide to Northeastern Moths and web sites like iNaturalist Vermont, BugGuide, Moth Photographers Group, or Moths of Eastern North America Facebook Group, moth watching (aka mothing) has become increasingly popular.

Moth watchers here in Vermont have added nearly 100 new species to the Vermont checklist via the Vermont Atlas of Life on iNaturalist and have documented nearly 1,400 species across the state so far via iNaturalist. What’s even more amazing is that we’ve recorded over 40,000 observations, which helps us understand their phenology, habitat use, and range in Vermont like never before.

Comments (2)

  1. Gretchen McFarland says:

    I currently live in the Pacific Northwest. One of the things I miss about the East Coast is watching the fireflies! Thanks for a great newsletter. The photographs are amazing.

  2. Richard Harlow says:

    Love the article!

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