September Nature Vignettes

 Encounters with nature and sustainability around Princeton in September.

One of my favorite corners in Princeton is near the middle school, at Guyot and Ewing. It's a small enclave, a triangle of sense, where the yards and the roofs of houses actually perform work, growing food and gathering energy. On one side is a small house with a small yard that the owner has turned into an orchard and vineyard, as might be more often encountered in Italy. 

Nearby is a house whose south-facing roof has been completely covered with solar panels for 20 years. 

When a house was torn down recently at the corner, I feared it would be replaced with something huge and unattractive, 

but instead, a one-story house with extra thick insulated walls and solar panels and interesting design is taking form. It was a real surprise to see a one-story house being replaced with another one-story house that is sensitive to the history of the site and seeking to fit in, while showing off a modern design that seeks to minimize energy consumption.

They even have a sign on the fence describing the project and what was there back in Princeton's agrarian era. 

Blooming along the fenceline next to the house are sunflowers and autumn clematis vine. Gorgeous as they are, thankfully generating color at a time when most flowers are spent, they are best not planted in a garden unless where the spread of their roots is limited by a house or pavement. Otherwise, given abundant sun to power their aggressively spreading roots, they will take over your garden.

Another common encounter in September is with late-flowering thoroughwort, which spreads not by roots but by seed. It can be weedy but also lovely and even elegant at times, and is great for pollinators. I couldn't get myself to pull this one out in our backyard, even though it has completely taken over a garden path.

At the Barden in Herrontown Woods, they are so plentiful that we don't feel too bad pulling out the ones that lean over the pathways.

The fight against invasive species has the side benefit of taking me to areas of a nature preserve where I wouldn't otherwise go. Recently, it led me to a patch of native diversity in Herrotown Woods that I hadn't noticed before.

Here is obedient plant, 

New York ironweed, 

and the post-flowering look of water hemlock. 

One of my favorite garden plants this time of year is stonecrop "Autumn Joy." 

A sedum, its disks of flowers go through a gradual enrichment of color from green to pink to deepening shades of red, then finally chocolate. Nonnative but noninvasive, it has the added benefit of being popular with pollinators. 

Pawpaw trees are becoming more common in Princeton. The patches planted in Herrontown Woods have yet to bear, but this one in my backyard reflects a growing interest in this unusual species native to the north yet with a tropical taste.

Native persimmons, likely once common in Princeton but often shaded out by larger trees in recent decades, are an attractive smaller tree that might actually bear edible fruit if you happen to get a female and harvest it just at the right time.

If the drought hasn't made the berries too dry, these blackhaw berries could make for some good picking after they darken. Blackhaw viburnum, Viburnum prunifolium, is the most common native viburnum in our woodlands.

Less generating of anticipation are the fruits of a female ginkgo tree, encountered growing near the Princeton Junction train station. The fruits have such an unappealing smell that people try to avoid planting female trees. 

Among inedible fruits, I call this the incredible shrinking pokeweed, because it initially grew to be seven feet tall--way too big to grow along a busy street. So I cut it down midsummer and thought that was that, only to have it sprout back as a smaller version of itself. You could try this technique with a number of perennial native wildflowers that get too tall for people's taste. Cut them down partway through the summer, then let them grow back in a miniature form. 

Though it dies down to the ground each year like a perennial wildflower, pokeweed looks more like a miniature tree, and in fact it has a close relative in Argentina. The ombu grows to the size of a large tree, yet lacks xylem. 

This shrub, too, needs to be cut back. It's an oak-leafed hydrangea I planted long ago in a little raingarden at the front of the Whole Earth Center. The landlord the store leases from must have a new landscape firm taking care of the grounds, because I stopped by recently to find that my native shrubs have been trimmed to look like bowling balls. Funny to see a native shrub and wildflower planting getting the bowling ball treatment. I'll have to take some loppers to restore light to the window next time I stop by to buy some beets or delicious bread.

Sometimes, frequently in fact, I find myself wishing I wasn't right. Take this ash tree for instance, planted by the people who landscaped the new parking lot that Westminster Choir College built about ten years ago. I told them they needed to remove the ash trees they had just planted. The emerald ash borers are coming, and the trees won't survive. They left the trees in. The trees survived longer than I expected, but are finally succumbing. 

Actually, if you were trying to make Princeton sustainable, you might want to "farm" Princeton with smaller, short-lived trees that provide shade but are less expensive to take down. The above ground portions could be periodically harvested as a local energy source, and the roots left in the ground would sequester carbon. Trees are a source of solar energy, since they draw their carbon not from underground but from the atmosphere all around them. Thus, no net increase in atmospheric carbon from their combustion.

The landscaping for the parking lot also called for a raingarden to be planted here in this hollow. After being planted, the young river birch trees soon began to wither for lack of water. I assumed they would die, and that the raingarden would be poorly maintained and ultimately be mowed down. I was only half right. The river birch trees survived.

Here's what looks like a bright white flower that isn't. The white is the puffy seeds that give the plant its name. The flower seems not to open but remain in what looks like a bud stage. It's pilewort, a native weed that can reach seven feet tall.

Finally, a grass encountered in fields and local rights of way. When its flowers open and display their golden anthers, this native member of the tallgrass prairies can be eye-catching. Indian grass, Sorghastrum nutans, reminds me of the midwest prairies I used to help manage, and a time long ago when prairie openings were common in the east as well.

Native Chestnuts in Princeton--the Next Generation

Many of us have lived our whole lives without seeing a mature native American chestnut tree. An excellent NY Times Magazine article described it as a true gift of nature, the perfect tree, growing straight and tall, with rot-resistant wood, and bearing nuts that were easily gathered and eaten, sustaining wildlife and people alike. My first encounter with the American chestnut was the sight of their fallen trunks in a Massachusetts forest, 70 years after the fungus that causes chestnut blight was discovered in NY city in 1904. The massive trunks I saw, lying on a slope in the shade of young white pine, were among the billions that the accidentally imported fungus would ultimately kill in the U.S. Since the roots survive the fungus, there was still a living community of underground chestnut trees beneath our feet in that Massachusetts forest. One of the roots had sent up a sprout about twenty feet tall--promising, one would like to think, but its slim trunk was already ringed by the fungus, its fate sealed before it could bear nuts. 

One of the projects I'm involved in is reintroducing native chestnuts to Princeton. The initiative began in 2009 with an email from Bill Sachs, a Princetonian with considerable expertise when it comes to nut-bearing trees. Bill reported that Sandra Anagnostakis, "one of (if not the) world’s leading experts on the pathology of American chestnut," had agreed to supply us with disease-resistant, hybrid American chestnut trees. Sandra's efforts to breed resistant native chestnuts at the Connecticut Agricultural Experiment Station over many decades was apparently unconnected to the American Chestnut Foundation. The trees were 15/16th native, and Bill with occasional help from me and others proceeded to plant them at the Princeton Battlefield, Harrison Street Park, the Textile Research Institute, Mountain Lakes and Herrontown Woods. 

Some fared better than others. Many, despite having been bred for resistance, nonetheless struggled with the blight that had laid the mighty tree low a century ago. This fall, however, paralleling our work to bring back native butternuts, one of the chestnut trees has borne fertile seeds.  

Bill made repeat visits to the tree to collect the nuts as they ripened. The deer likely got many, but he managed to gather quite a few, some of which he encouraged me to cold stratify. Stratification has always been an intimidating concept for me, suggesting sophisticated manipulation to get a seed to germinate, but in this case it turned out to be not much more than stuffing some seeds in a bag of moist peat moss and leaving it in the back of the refrigerator for awhile. 

The tree, hosted by TRI near Carnegie Lake in eastern Princeton, bore generously despite significant pruning by the periodical cicadas early in the growing season. 

This past summer a friend had sent me a photo of another chestnut tree that, being smaller, was much more affected by the cicadas' egg-laying activities. They cut into stems to lay their eggs, which ends up killing the foot or two of stem beyond where the eggs are deposited. 

We'll see how these various trees do over time, and if a second generation of these mostly native chestnuts comes into being. The NY Times article was mostly about efforts to develop a blight-resistant American chestnut through genetic modification. That thirty year project, with a geneticist named William Powell as the main protagonist, has been successful. They managed to find a gene in wheat that confers resistance when inserted into the chestnut's genome. 

Adding one gene would seem a much more precise and less intrusive means of correcting a century old wrong than adding many genes, most of which are irrelevant to improving resistance, from asian chestnuts. But don't expect these ever so slightly and efficiently modified native chestnuts to be available any time soon. There are strict regulatory hurdles that must be overcome. 

For me, the situation demonstrates two powerful forces in the human world. One is the fear of the slippery slope. Would an elegant genetic fix for the American chestnut open the doors to a wave of less admirable genetic modifications of our world? The other powerful force is our focus on regulating intentional change, while allowing unintentional change to run rampant. While the government spends years deliberating over one gene being added to the native chestnut tree, global trade is introducing an ongoing wave of new organisms to the country, any one of which could be the next emerald ash borer or spotted lanternfly. 

In the meantime, we'll be thankful for the mostly native chestnuts we have, and see what we can grow.

Below is more info I've taken from some of Bill Sachs' emails. Click on Read More. 

Chance Encounters with Trees in Lambertville and New Hope

My awareness of trees made me a mixed bag as a companion on a recent visit to Lambertville. The same eye that spots nature's wonders makes it hard to ignore tragedy.

My first find was a red mulberry tree, encountered on the Lambertville side of the bridge, draping itself over the canal. My daughter and I gorged on the berries.

Most mulberry trees grow straight up, leaving the abundant berries frustratingly out of reach, but this one grows right out of the old stone wall of the canal. Suspended above the water, its limbs grow horizontally towards the sidewalk, making for a beautiful presentation of berries to passersby.

The view down the Delaware River from the bridge was glorious, the air above the long-traveled water fresh and richly scented. It was a time to be positive, to focus on the upside, but I couldn't help scrutinizing that seemingly verdant distant hillside. 

There, mixed in with the green, was evidence of the massive dieoff of ash trees--a profound moment in history that we are living through, ever since the Emerald ash borer hitchhiked to America in the wood of packing crates twenty years ago. 

There are immense ash trees perched on the bluff overlooking the river, like the grove on the left here that shaded us as we began our leisurely walk across the bridge. They are still green enough to deceive most people, but will end up like those just to their right in the photo. These observations could have triggered thoughts of past dieoffs that transformed our forests, marginalizing once dominant trees like American chestnut and elm, but

fortunately, there was a more positive tree story to shift to. Walking across the bridge, I noticed an improbably large tree rising above the houses along the shore in New Hope that looked to be flourishing. Later, I ducked down an alley to have a closer look. A bicentennial plaque in front of it says it was alive at the time of the signing of the U.S. Constitution in 1787. That makes it more than 234 years old.

A man living next to it, who grew more friendly once he realized we were interested in the tree, said it's a willow oak. 

When I lived in North Carolina, we had many willow oak trees. Conveniently, their narrow leaves would settle in nicely with the pine needles, and after a few years I let that mix of leaves and needles replace the lawn as a pleasing surface for the yard. 

Some of the branches of this specimen would be impressive trees on their own.

New Hope prospered early on because of the ferry, and also because of the mills powered by the steady springfed waters of the resident stream. Tucked behind the Bucks County Playhouse, which used to be a mill, this dam frames a scenic, misty cove. A great blue heron stood stockstill, scrutinizing the falling waters, waiting for the stream to deliver dinner.

As if it were an old friend, I pointed out the native indigo bush lining the shore below the theater. I didn't get much of a response from my companions, but for me, knowing the plants makes it possible to feel familiarity even in a place where one knows no one at all, and makes an extraordinary place all the more extraordinary. 

Related reading from 2015: A Steamboat Named SPLASH: Riding the Real Deal on the Delaware River

Some Unusual Trees

 Here are some encounters with unusual trees in Princeton. 

In the Institute Woods, we saw a couple beech trees some distance from a trail and took a closer look. Not quite the California redwood that people could once drive a car through, but similar in concept. 

Another beech nearby was harder to pose with.

The view up the inside of the trunk.

Bark with this shaved appearance, seen recently in a deep forest in northeastern Princeton, is called "ash blonding," said to happen when woodpeckers go after the emerald ash borers inside the ash tree. Note the tell-tale "D"-shaped holes where the borers exit. 

More uplifting was this tall spruce, which during the holidays sports a shining star, which then gets replaced on the owner's March 17 birthday 

by an Irish clover. 

Here's an odd sighting. It looks like an ordinary stump, but the tree was clearly cut down and removed. The forest is quite old, so the logging must have been long ago. My guess is that it's the stump of a chestnut tree harvested a century ago. One of the many wonderful traits of the native chestnut, lost to an introduced disease a century ago, was its resistance to decay. Working briefly for a forester in Massachusetts in the 1970s, I saw whole logs of fallen chestnuts still intact despite the passage of many decades. I'm ready to be wrong on this ID, but that's what I'm going with for now.

A month ago, I stopped by the TRI property to check up on a couple native butternuts planted there by Bill Sachs. The two trees are flourishing except for some vines that I really need to get back there and cut. They were planted close to where Bill and I harvested about fifty nuts, perhaps the last native butternut harvest in town before the bounteous tree was blown down in a storm. Thanks to Bill, the harvest turned into many saplings that we've planted in many locations in town, including Harrison Street Park, Herrontown Woods, Mountain Lakes, Stone Hill Church, and TRI. The tree has a gangly growth form, but the nuts are said to be delicious. The tree needs our help because of an introduced disease that has laid it low. This one's look really healthy thus far.

Some other stories about unusual trees:

How lightning that struck one tree at Morven actually killed the adjacent tree instead.

An extraordinary giant white pine that may still grow near 206.

Recreational Trails and Resilience

The Friends of Herrontown Woods and other stewards of natural lands in Princeton have been asked to give input to the state bike/ped office and the Federal Highway Administration about trail resilience in these times of rapid change. I decided to put my feedback into a blog post. We steward trails at Herrontown Woods and Autumn Hill Reservation in Princeton, NJ--about 220 acres total. Fit into the categories we were asked to address, here is some of what we've learned over time:

Trail vulnerability and resilience to natural hazards

Climate change is impacting our trails in multiple ways. Trees still pull water out of the soil during the growing season, making most trails reasonably dry during the summer and fall. In the past, winters were cold enough to freeze the ground in the winter. Now, with warmer winters, trails can get wet from rains in the fall and remain wet and muddy until the trees awaken again in late spring. 

Trails are becoming more vulnerable to erosion, give the more intense, longer, and more frequent rains, and the reduction in freezing in winter. Trails on a slope can become like streams as they catch runoff from the surrounding ground and convey it downhill. This makes water bars, which serve to divert runoff from trails, all the more important to build and maintain. 

As ash trees killed by the introduced Emerald ash borer become brittle over time, they will fit in the category of natural hazards. We've been fortunate to be able to take some down in the vicinity of our botanical garden, but it would be impossible to cut down all of them in the forest. They can serve as useful snags for wildlife, at least.

Designing trails for climate change and future conditions

We ground-truth potential new trail routes during the wettest times of the year. This has become all the more important as weather becomes more extreme. It's the only way we can know whether a particular route will be usable year-round. A route that looks dry during the summer may be impassable in the spring, when vegetation has yet to pull moisture out of the soil. This is the problem with having trail consultants spend a couple days in a preserve, and then make recommendations about trail routes. Ongoing observation is really helpful.

In some of our soils, it is the roots that maintain the firmness of the soil. We've been deceived at times by a seemingly dry route that, when it becomes a trail with lots of foot traffic, becomes muddy due to the breakdown of the underlying root structure that had been holding the soil together. 

No trail can be perfectly designed. We fortunately have a source of local "native" stepping stones that we can lay down on particularly muddy patches, and we use some boardwalking. Over time, we hope this will keep trails passable even as rain increases. 

Trails providing ecosystem services

Trails provide access to areas to cut invasive species or do other stewardship work. If invasive species are controlled along trails, the trails become essentially a corridor of restored habitat. Interestingly, trails can sometimes provide the necessary combination of disturbance and additional light necessary for some wildflower to grow that would otherwise get smothered by leaves or shade in off-trail areas.  

On the downside, trails can intrude on habitat, and also provide a route by which invasive plants like stiltgrass can penetrate into otherwise uninvaded areas of the preserve. 

Use of trails during emergencies (evacuation routes, emergency vehicle access, fire suppression, etc.)

We invited the the local rescue squad to do a practice rescue in our preserve. It was very helpful in acquainting them with the lay of the land. We also showed them areas where accidents could potentially happen, and are working on a better map of the preserve showing access points. 

Trails can serve as potential fire breaks, whether for fire suppression or for prescribed burns. We have yet to use fire as an ecological tool in the preserve, but fire often has a positive and historically important role in open spaces if prescribed and carried out appropriately.

Use of recreational trails during public health emergencies

We've seen a dramatic increase in trail use this past year, as well as an increase in volunteers to help at our preserve. Though hikers tend to be conscientious about wearing masks, some will want to avoid encounters along narrow trails. That gets us looking at how we could provide at least one trail that is wider than others. 

Nature has served as an indispensable balm, refuge, and recreational outlet for people during the pandemic. The pandemic has made nature preserves ideal for those who love not only plants and wildlife, but socializing safely with people as well. 

Optimism, Habitat, and Landscape

If people love trees so much, then how do we explain Jill Biden's choice for a painting that was part of Inauguration Day ceremonies in the Capitol rotunda. Painted by African American artist Robert Duncanson as the Civil War was looming, Landscape With Rainbow depicts a pastoral paradise in which a young couple and their cattle head back to a homestead blessed by a rainbow. 

A closer look reveals that the distant hills in the painting are forested, but it is pasture--albeit a bit overgrazed--that dominates this optimistic landscape. Though people love trees, we also love vistas, which trees are very good at blocking. Who hasn't climbed a mountain, expecting a grand vista at the top, only to find that trees have grown to block the view? 

It seems strange sometimes that communities don't actively seek to create and preserve vistas, given how pleasing they are. If people can see into the distance, maybe they'll think into the distance as well. A vivid memory from the Sourland Mountains, just up the road from Princeton, is a view of the Manhattan skyline. It came as a complete surprise, and was made possible only by the ongoing suppression of trees along the gas pipeline right of way that extends up and over the mountain ridge. Ideally, vistas would be made possible in our world by something less linear and fossil fuel-related than a pipeline, but our approach to managing preserved open spaces seldom offers an alternative means of creating areas that are more open. 

Also running counter to open space preservation norms, the focus of optimism in the painting is a house, embraced by nature, towards which the rainbow, people and animals all point. One approach to purchasing open space for preservation is to demolish any buildings left on a newly preserved property. We had to overcome this bias against buildings embedded in open space in the process of saving Veblen House and Cottage at Herrontown Woods. 

One question, then, is how to adjust the classic view of open space--as uninterrupted forest--to consider the clear attraction we have for the mosaic of habitats depicted in this painting, where people play an active role in the landscape. What is pleasing to people can also serve the needs of biodiversity. At the Botanical Art Garden at Herrontown Woods, we are actively preventing a forest opening from reverting to the deep shade that stifles the growth of so many native plant species less gifted with height. Succession to forest need not be considered the only natural destiny for a landscape. Historically, such forest openings would have been maintained by periodic fire, in what is called a fire-climax community. 

Though a deep forest of towering native trees can evoke a sense of awe and reverence, and deserves to be preserved, many areas of preserved open space are thick with stunted, second-growth trees. Add the typically dense layer of invasive shrubs and the effect becomes cluttered and claustrophobic. As the death of ash trees due to the Emerald Ash Borer opens up the forest canopy, we may want to manage some of these openings to create a more varied habitat. If the non-native invasive shrubs can be limited, and young trees kept from reclaiming the sunlight, there are many native shrubs that could flourish in a more illuminated understory. Spicebush, hazelnut, serviceberry, native azalea, blueberries, Viburnums, Hearts-a-burstin'--these are a few of the native shrubs that would bear abundant fruit for wildlife if given more sun. 

One of the most optimistic moments I had in my life had some parallels to the Duncanson painting. I was driving out of Washington, DC after picking up a passport. The president at the time was highly competent and believed in government, and the WhiteHouse gleamed brilliant white in the afternoon sun as I drove past. On the radio was a live broadcast of Copeland's Appalachian Spring, broadcast from the Library of Congress in honor of its premier performance there some 50 years earlier. Along the roadsides as city began to transition to countryside were prairie grasses, golden in autumn. The youthful roadside vegetation resonated with the music of spring's awakening, and a sense of the nation's promise. 

Grasslands, meadows, shrublands--these are the younger landscapes, whose dynamic growth happens at our own height rather than far above. Their flowers and foliage also serve the insect community through the summer when deep forest has gone floristically silent. The aim here is to become more strategic and discerning about trees, to determine where they are precious, and where they might best be managed to serve ecological and aesthetic goals. 

Spotted Lanternfly in Princeton

Most people by now have heard of the spotted lanternfly, an insect native to China, Vietnam and parts of India that somehow showed up in eastern Pennsylvania in 2014. A leaf hopper with distinctive markings and colorful wings, it spread rapidly as it sucked the juices out of grape vines, orchards, and trees like Ailanthus, black walnut, maple and red oak.

Two years ago, local papers reported a sighting of spotted lanternfly in northeastern Princeton. Last year, the summer of 2019, a couple friends reported seeing it in Princeton--Mimi found a few in her backyard in western Princeton; Scott saw some in Herrontown Woods near the parking lot. 

For me, it didn't become real until I encountered this curiously tilted nymph on a butternut tree leaf near Veblen House in Herrontown Woods in early July. A Penn State Extension post describes the insect's colorful development from egg to nymph to the winged adults that emerge in late July.

For some reason, I had avoided writing about the spotted lanternfly. Maybe I was maxed out on the world's problems, and didn't really want to delve into the prospect of yet another introduced insect wreaking environmental havoc. 

Unlike the Emerald ash borer, which has gone largely unseen as it skeletonizes our vistas, quietly killing every untreated ash tree in Princeton, 

the spotted lanternfly sounded poised to make a highly visible and messy invasion. The PA Dept. of Agriculture published a pdf with graphic photos showing mildewed foliage and tree trunks covered with the adult insects. And because plant juice is very dilute, the sucking insects need to move a lot of juice through their bodies to get the nutrition they need. That means that both nymphs and adults expel large amounts of "honeydew", which drops down from the trees and vines, and coats foliage on the ground with sugary liquid, promoting the growth of mold. Their egg cases look like mud, affixed to trees or cars or most anything. It sounded like our habitat restorations and garden beautifications would be reduced to a tattered, moldy mess.

Below are compiled some research and experiences with spotted lanternfly this past weekend at Herrontown Woods. 

Ailanthus--the Spotted Lanternfly's favorite food

Turns out that the spotted lanternfly has a strong preference for sucking the juices of Tree of Heaven (Ailanthus altissima). Native to China, Ailanthus is fairly common in Princeton and can be invasive, forming clones and sprouting aggressively from its roots if cut down. A stand of Ailanthus can be used for trapping the spotted lanternfly. Penn State extension offers tips for homeowners on this. 

At the Herrontown Woods botanical garden, next to the parking lot, we have an Ailanthus growing, and sure enough, some adult lanternflies were found clinging to its bark.

Looking up, the Ailanthus leaves appear to be getting eaten, though the lanternflies are said only to suck from the trunk and the stems, not the thinner tissue of the leaves themselves. 

In a sense, the preference for Ailanthus is good news. An invasive tree is being attacked by a newly introduced insect from a similar region of the world. But the tree is also helping the insect expand its numbers through the summer, and toxic compounds in Ailanthus, when ingested by the lanternfly, may confer some protection from predators.

The lanternfly's honeydew is causing sooty mold to grow on the plants underneath the tree.  The NJ Dept. of Agriculture info sheet reports that the sap dripping from "weeping wounds" on tree trunks can attract stinging insects. 

Probably the best thing to do is to take down the Ailanthus, using techniques described here.

More advice for homeowners

There's an enjoyable and clever article on various tactics on the MercerMe site. For instance, the adults are very quick to jump if you try to squash them. The article says their reflexes slow down with persistent efforts, however. Will test that next time. 

Utilizing more finesse is a trap a Pennsylvania teenager came up with after watching the lanternflies climbing the trunks of trees. She ringed the tree with tin foil to channel the ascending insects into a bag, where they would die within 24 hours. Another thorough read for homeowners is at this link, including a test to see if chickens would eat them. They didn't,

but something is clearly eating them, as these wings at Herrontown Woods show. 

Longterm prognosis

Will the spotted lanternfly prove to be a longterm calamity, like the Emerald ash borer, or fade into the background as a passing problem? Will it be a lasting plague for vineyards and apple orchards? An article reports that few lanternflies were seen this year in the area of Pennsylvania where it was first discovered five years prior.  Local Princeton arborist Bob Wells is quoted in the Town Topics as saying that though vineyards and apple growers have reason for concern, for homeowners the insect "won't be much of a threat at all." I inquired on a listserve that includes land managers in Pennsylvania who have had the insect around for several years now, and got mixed responses. One observed reduced numbers one year, then a rebound the next. 

It can be hard to know if you have spotted lanternfly in your trees. My friend LisaB, who lives near Herrontown Woods, had a couple black oaks fall near her property in late July, and was surprised to find numerous SLF nymphs on the leaves that until then had been elevated 70 feet above the ground. She had seen none in her yard up to that point. Her photos show the last nymph stage (red), 

  

and a beautifully captured example of what a newly formed adult looks like. Documented in past posts on this blog, insects like cicadas, butterflies, and apparently spotted lanternflies as well, must hang down as they unfurl their new wings. If the wings brush up against any obstruction, they can easily become misshapened. 

Update, Aug. 6: Walking through Quarry Park, closer to downtown, I noticed some Ailanthus trees near Spruce Circle,  looked up at the leaves above, and saw them there as well, a few scattered adults sucking juice from the rachis of the compound leaves. Will the spotted lanternfly be background or foreground, a quiet addition or serious pest? Time will tell. 

In the meantime, it looks like removing Ailanthus trees would be the most straightforward way to limit this new arrival's numbers and impact.

Reporting: I tried reporting the Herrontown Woods and Quarry Park sightings. The email address bounced, and the telephone number is always busy. It may be that the state doesn't want to hear about sightings in counties where the insect is already present, or maybe it's so widespread by now that the information isn't helpful.

Does milkweed kill lanternflies?

On the leaves of common milkweed growing near our Ailanthus tree, I found several lanternflies belly up or immobilized, leading to speculation that the insects sucked juices from the milkweed and died from the toxins therein. Apparently, as an introduced species, they have yet to evolve an aversion to the plant.