Blog Home Vermont Center for Ecostudies
View of Woodstock from Mt. Tom lookout © Kent McFarland

Field Guide to July 2024

The dawn bird chorus now fades from northern woodlands as the hills erupt in the sparkle and drama of summer insects. Dragonflies dart through fields and along pond edges. Moths and butterflies in all shapes and hues flit across the sun-washed landscape. In July, Vermont's hills and valleys pulse with the rhythm of wildlife antics. Here's a guide to some of the splendor.

By Vermont Center for Ecostudies July 15, 2024
Polyphemus Moth (<i>Antheraea polyphemus</i>) © Kent McFarland
Polyphemus Moth (Antheraea polyphemus) © Kent McFarland

Join the Vermont Moth Blitz During National Moth Week July 20-28!

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 every July, National Moth Week offers everyone, everywhere a unique opportunity to become a community scientist and contribute information about moths. You can help map moth species distribution. Just find a moth, snap a photo, and add it to the Vermont Moth Blitz project on iNaturalist!

Deer Tick (<i>Ixodes scapularis</i>) in Vermont © VCE Tick Technicians
Deer Tick (Ixodes scapularis) in Vermont © VCE Tick Technicians

Where Do Humans Fit Into the Cycle of Tick-borne Disease?

By Pia Carman

“I admire its purity. A survivor… unclouded by conscience, remorse, or delusions of morality”
Alien, 1979

In Ridley Scott’s Alien, the fear of parasites living off humans was popularized in a story set on an uncharted moon 39 light years from Earth. That’s a long way to go to experience a phenomenon that’s alive and well in our own backyards. While not quite the same as the creatures in Alien, ticks readily parasitize warm-blooded hosts like deer, dogs, and humans.

Deer Ticks, arachnids infamous for spreading Lyme disease and anaplasmosis, are sorely misunderstood. Despite their namesake, Deer Ticks are not exclusively found on deer. In fact, White-tailed Deer (affectionately called “the bar” by some tick ecologists I know) are only involved in the tail end of the tick’s life cycle when they seek mates. At this stage, deer serve as the meeting ground for female ticks to find a mate and gorge themselves before detaching and laying their eggs. Additionally, the pathogens Deer Ticks are so famous for carrying do not directly infect ticks; Lyme disease-carrying ticks are not sick themselves, but merely transport pathogens between sick animals and uninfected animals in their search for food.

The pathogens carried by deer ticks are actually found in more unassuming animals than White-tailed Deer—small mammals like mice, voles, and shrews. After a well-fed Deer Tick lays her eggs in late spring, the developing larvae emerge in summer to find their first blood meal. A fast, long-legged animal like a deer is hard to come by when you’re only as big as a grain of sand, so when you’re hungry for the first meal of your life, one of your best options is foraging rodents brushing their low-lying underbellies against the ground. And if you’re a tick-borne pathogen ready to hitchhike to a new host, a friendly parasite like a tick is your free ride. After their first blood meal, overwintering ticks only grow to the size of poppy seeds in their nymphal stage, and small rodents remain a solid source of food and pathogens.

When people contract Lyme disease, that strain of bacteria hitchhiked from a small mammal to human hosts, who historically have not been a Deer Tick’s “bar” of choice. After all, ticks are just animals looking for their next meal, not a source of evil with a vendetta against larger animals. Evolutionarily, humans have no resistance to the bacteria that cause Lyme disease whereas many small mammals have partial resistance, enough to avoid being debilitated but not enough to clear the pathogen from their system. For their part, White-tailed Deer cannot transmit Lyme bacteria at all. Our novelty to this pathogen-tick cycle as accidental hosts for ticks makes us particularly vulnerable to the disease.

Best practices to protect against Lyme disease include checking for ticks (look closely—tick nymphs can be as small as a pencil tip!) and drying your clothes with high heat after walking through leaf litter and brush at the edges of forests.

Evening Primrose Sweat Bee (<i>Lasioglossum oenotherae</i>) in Waitsfield, VT © Bernie Paquette via iNaturalist licensed under CC-BY, some rights reserved
Evening Primrose Sweat Bee (Lasioglossum oenotherae) in Waitsfield, VT © Bernie Paquette via iNaturalist licensed under CC-BY, some rights reserved

Specialized Species: A Study in Pink & Yellow

By Gita Yingling

As a budding ecologist who grew up in central Texas, I’ve long been an admirer of the Pink Evening Primrose (Oenothera speciosa). I said a mournful goodbye to the delicate wildflowers before my parents moved up to Vermont. After a few months of living here, I was surprised and delighted to learn that the Common Evening Primrose (Oenothera biennis) would show up in midsummer, decorating the hillsides of my new home! This taste of Texas is native to eastern and central North America, where its bright yellow color, four petals, and long stamen make it a common sight during Vermont summers. Primrose is pollinated by multiple moth and bee species where it grows in fields, thickets, and along woodland borders. And though it attracts a plethora of pollinators, two have a specialized relationship with the flower.

Among the insects that aid in the pollination of this primrose, none are as well equipped for the task as the Evening Primrose Sweat Bee (Lasioglossum oenotherae). These sweat bees have developed a close relationship with this and other narrow-leafed primroses due to one defining characteristic—the long leg hair of the female worker bees. These large, shiny, black bees’ scopa—the masses of hairs on its legs—have evolved to be maximally efficient at handling evening primrose’s pollen grains, which are held together by sticky threads called viscin. Once caught on the sweat bee’s distinctive leg hair, ropes of primrose pollen can be transported to another flower. Essentially, we can think of the scopa as hooks that transfer chains of pollen among plants as sweat bees collect the pollen to feed to larval young. In this manner, the cycle continues for generations of both plants and insects.

Primrose Moth (<i>Schinia florida</i>) in Aitken State Forest, Mendon, Vermont © Susan Elliott via iNaturalist licensed under CC-BY-NC
Primrose Moth (Schinia florida) in Aitken State Forest, Mendon, Vermont © Susan Elliott via iNaturalist licensed under CC-BY-NC

This hairy relationship isn’t Common Evening Primrose’s only specialized plant-insect interaction. The Primrose Moth (Schinia florida) is clad in cute pastel colors that may remind Vermonters and moth lovers alike of the Rosy Maple Moth (Dryocampa rubicunda). Except, rather than a maple tree, this yellow and pink moth uses the Common Evening Primrose flower as a host for its lifecycle.
Unlike the pollinating Primrose Sweat Bee, the Primrose Moth is greedy in its relationship to the evening primrose. The cycle of selfishness starts when an adult moth lays its eggs in the primrose flower. Then, instead of helping the host plant out by pollinating the flower, the larvae munch on the flower buds, damaging the plant’s reproductive organs. However, it’s only when larval populations are especially high that any serious damage is done via herbivory.

After an unfortunate loss for the plant and a nutritious meal for the moth, the former caterpillars emerge from their cocoons as winged adults. At this stage, the moths spend their time hiding in partially closed flower buds during the day, camouflaging into the plant so an onlooker would only see the creamy yellow tips of their wings popping out from the petals. When the sun sets, the flower buds open and the moths come out, ready for a sugary drink. The Primrose Moth has a notably long proboscis (about half of its entire body length!) that they use to drink nectar from the flowers.
The adult moths go on to spend their days drinking nectar through their straw-like tongues. As the flowers begin to wilt, and their sunny yellow fades to a pink color, the Primrose Moth remains camouflaged thanks to its pink fuzz. These pink pastel pests have now taken advantage of the Common Evening Primrose throughout every stage of their lifecycle—without providing the benefit of pollination. Despite the hungry caterpillars eating the buds of the plant, this plant-insect interaction continues through generations of both flowers and moths.

Interspecific relationships range across a spectrum from mutually beneficial to mutually harmful. On the positive end of the spectrum, the Common Evening Primrose gets what it needs from the Primrose Sweat Bees’ pollination as the sweat bee harvests pollen and nectar. In a more one-sided specialized relationship, the Primrose Moth gets a camouflaged refuge and food source throughout its life cycle. Together, these relationships and the ones in between make up the complex ecological web present in the natural systems around us.

14689, , IMG_0251, , , image/jpeg, https://vtecostudies.org/wp-content/uploads/2024/06/IMG_0251.jpeg, 1875, 2500, Array, Array  © Pia Carman, VCE
Eastern Red-backed Salamander on Mount Cardigan, NH © Pia Carman, VCE
14688, , 4F4DCDE7-9CF3-4CF4-A094-D023E1104131_1_105_c, , , image/jpeg, https://vtecostudies.org/wp-content/uploads/2024/06/4F4DCDE7-9CF3-4CF4-A094-D023E1104131_1_105_c.jpeg, 768, 1024, Array, Array  © Gita Yingling
Wolf’s Milk-slime (Lycogala epidendrum) on Mount Cardigan, NH © Gita Yingling

Seeing Red: Wolf’s Milk-slime and Red-backed Salamanders

While some outdoorsy Vermonters spend their summer leisure time fishing, boating, or gardening, others find enjoyment spotting decomposing logs along wooded trails.

By Pia Carman and Gita Yingling

On a sunny June day, the VCE summer interns took a hike on Mount Cardigan and excitedly herped all the way to the top. When seeking out downed woody debris for flipping, we looked for soft, dark-brown logs, which are rich in nutrients and moisture, making them a favorite hiding spot for salamanders and other secretive herps. A common sight when you eagerly turn over a log is your friendly neighborhood Eastern Red-Backed Salamander (Plethodon cinereus). These little guys are slithery, brown and red, and so small they don’t need lungs—instead, they can breathe through their skin!

These small but mighty creatures are one of the most common terrestrial vertebrates in the moist hardwood and mixed forests of New England. There, they play a pivotal role in maintaining forest health, preying upon small invertebrates like ants, spiders, snails, centipedes, and beetles. By controlling these organisms, which include numerous fungivores, red-backed salamanders contribute to the breakdown of woody material and leaves into soil.

Given this relationship, it was easy to assume that the bright red splotches on a log concealing a red-backed salamander were a fungus. Curious to find out what fungus we found, we turned to iNaturalist. A quick search yielded a surprising result—these little blots on the log were not fungi at all. They were a slime mold amoeba called Wolf’s Milk-slime (Lycogala epidendrum).

With a name that sounds like something out of a low-budget werewolf flick, the Wolf’s Milk-slime lives a fascinating life. As amoebas, they are single-celled organisms that spend most of their life invisible to the naked eye but occasionally aggregate to form a single mass of many individuals called a fruiting body to reproduce (which is what we were lucky enough to witness in person). In the immature stage of this fruiting body, its insides contain a pinkish slime, which we confirmed by popping one of the fruiting bodies we found. When mature, the fruiting body’s slime turns to a gray powder of spores. This fascinating enigma of an organism feeds on cells, spores, and particles of fungi, plants, protozoa, and other organic matter.

If you take a moment to stop and look, a great deal can be learned from just a single log. Along our journey to the summit, we found two species deeply intertwined with the cycling of matter in forests. Our observations showed us one organism that consumes invertebrates, which consume fungi, which consume organic matter. In the slime mold, we also found an organism that feeds on both fungi and decaying wood. Learning about these two species came from a chance encounter. So, next time you’re out in the field or on a hike, try turning over a few logs. You will probably find amphibians, and if you’re lucky, you’ll also find the fruiting body of a plasmodial slime.

Ovenbird (<i>Seiurus aurocapilla</i>) © Kate Taylor via iNaturalist licensed under CC-BY-NC
Ovenbird (Seiurus aurocapilla) © Kate Taylor via iNaturalist licensed under CC-BY-NC

Ovenbirds and Canada Warblers: An Exercise in Luring Birds

By Pia Carman

Nearing the top of Mount Cardigan, Dr. Desirée Narango and I stopped in our tracks after hearing the characteristic “teacher-teacher-teacher” call of an Ovenbird (Seiurus aurocapilla), whom she affectionately calls the “chickens” of the forest. Although we heard the bird, it was nowhere in sight. So, Dr. Narango introduced me to “pishing,” which involves making a shushing noise with a ‘p’ sound in front that imitates warning calls made by many birds and draws them closer to you by piquing their curiosity. Ovenbirds are evidently one of the most aggressive, or territorial, birds we found since just one round of pishing drew the bird into view. Examining us, the bird flew to the ground, strutting in the undergrowth like a chicken would.

Canada Warbler (<i>Cardellina canadensis</i>)  © Susan Elliott via iNaturalist licensed under CC-BY-NC
Canada Warbler (Cardellina canadensis) © Susan Elliott via iNaturalist licensed under CC-BY-NC

This strategy worked similarly well with the Canada Warbler (Cardellina canadensis) we saw later on; however, he was far more cautious and restrained than the Ovenbird, staying in the tree canopy above. These birds make an extraordinary migration every year, traveling to their breeding grounds in the northeastern U.S. and Canada during the summer months and residing in northwestern South America during the winters. It occurred to me that this tiny bird travels more than me. I envy you, Canada Warbler.

Deerfly species from left to right: Sherman's Deer Fly <i>(Chrysops shermani)</i>, <i>Chrysops indus</i>, Black Deer Fly <i>(Chrysops niger)</i> © Spencer Hardy
Deerfly species from left to right: Sherman's Deer Fly (Chrysops shermani), Chrysops indus, Black Deer Fly (Chrysops niger) © Spencer Hardy

An Ode to the Dreaded Deer Fly

By Spencer Hardy

Everyone knows the deer fly–but do you REALLY know the deer fly? With approximately 29 species in the genus Chrysops in Vermont, there is a lot to know. For example, larvae can live up to three years as decomposers and predators in water, and the eyes of adult deer flies are among the most psychedelic things in the natural world. A few species even have color patterns that rival any butterfly. Males (which are rarely encountered) don’t bite and are potential pollinators since they visit flowers for nectar.

In many ways, they are the perfect group for nature enthusiasts–ubiquitous, diverse, easy to ‘collect’, and relatively easy to ID–yet for some reason, they don’t get the attention they deserve. July is an ideal time for deer fly appreciation since diversity seems to peak early in the month and overall abundance climbs through the end of the month. Boggy, forested areas are great places to find uncommon species, but every site seems to have a unique suite of species, with as many as 10 different species in a single area.

So next time you swat one off the dog or pull one from your hair, take a second to appreciate it and then photograph it for the Vermont Atlas of Life on iNaturalist. A clear shot of the wings and abdomen is enough to identify many species, though side and face shots are also helpful. A straightforward and well-illustrated key can be found here. There are also plenty of other Tabanidae that you may encounter as well, including some frighteningly large ones and a genus (Stonemyia) that only visits flowers and doesn’t suck blood. Just maybe, come September this year, you will find yourself missing deer flies!

Water Mite <i>(Arrenurus)</i> larvae on a Dragonfly © K.P. McFarland
Water Mite (Arrenurus) larvae on a Dragonfly © K.P. McFarland

It’s Not Just a Ride, It’s Phoresy

By Kent McFarland

I really don’t like weeding. So it was with great pleasure when, just moments into the task, I spotted a dragonfly acting strangely on a nearby plant. What immediately caught my eye was a pile of tiny, red, egg-like sacs all over its thorax. I ran to grab my camera, and at this point, I am sure my wife was rolling her eyes. Anything to get out of weeding. But heck, I was just about to bear witness to phoresy.

Frankly, I didn’t know the term either. But it turns out that those little red sacs weren’t eggs at all, but rather larvae of water mites hitching a ride on the dragonfly. Ecologists call it phoresy, the process of using another organism to move about.

Arrenurus water mite adults are a mere three millimeters long and usually brown or greenish, so you wouldn’t notice them in the water unless you were really looking for them. They mate in spring, and the female lays up to 400 red eggs on underwater objects, one egg at a time.

The six-legged larvae hatch in one to six weeks, depending on water temperature, and they immediately swim around looking for an insect larva. When they find a mosquito, stonefly, damselfly, or dragonfly larva in its late stages of growth, they grab onto it, waiting until the insect goes airborne.

After the dragonfly larva crawls out of the water and sheds its exoskeleton, the mites jump off the cast shell and onto the dragonfly. Now they are not only hitchhiking, but they also become parasites. They form a tube that pierces the exoskeleton of the dragonfly so that they can feed on the victim’s hemolymph, kind of like blood in an insect’s circulatory system. After the mites grow enough, their exoskeletons become like sacs, and the larvae inside develop into nymphs.

When a nymph is fully developed, it just drops off the host when it is over water. Now, like all arachnids, it has eight legs and looks similar to an adult water mite. They eat the same foods as adults too—tiny insects, worms, and even other mites. After they eat and grow, if they avoid being eaten themselves, they find an object to attach to and form another sac to develop into an adult.

It’s a complicated life cycle for the minute water mite. I never would have guessed that they visited our nicely weeded garden far from water.

Leave a comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.