Showing posts with label Insects. Show all posts
Showing posts with label Insects. Show all posts

Friday, August 04, 2023

Four Kinds of Honey Bees in Northern Thailand

These bee hives look like something Winnie-the-Pooh might stick his paw into. The hives are made of hollowed out sections of tree trunk. The photo was taken by my daughter Anna, who was traveling this summer in southeast Asia. 

To escape the heat, she and her boyfriend headed up into a mountainous region in northern Thailand called Chang Rai, where the residents drink three kinds of tea and grow four kinds of honey. She was surprised to learn that the black, green, and white teas all come from the same plant--the same species of tea. But the four kinds of honey are not made by the same kind of bee. This is four kinds of honey made by four species of bees. Thailand, it is claimed, has the greatest bee diversity in the world, including half the world's species of honey bees, and in this tiny village the various honeys they produce are an important part of the diet. 

There's the honey we're familiar with, and then there's another one that tastes like apricot jam. A third, produced by the stingless bee, has a fermented fruity flavor like Kambucha. 

Another species, the asian giant honey bee (Apis dorsata), can't be kept in a hive, so villagers climb trees to reach the honey. Wooden footholds are placed in the tree trunk to expedite the climb. The giant honey bees don't stick around all year, but instead migrate up to 200 kilometers, returning to the same branch six months later.

The asian honey bee (Apis cerana) produces less honey than our honey bee, but is much easier to take care of

A Brief Account of Life in a Mountain Village in Thailand

Their first night in the village, they were surprised to be awakened at 3:30am by the robust crowing of roosters, so raucous that the whole village has little choice but to rise and begin its day. Chickens run loose, apparently free of local predators that might consume them before people have a chance to. Once a year, a tiger passes through the area, apparently without raising much concern.

The town runs on solar energy, but lest one think this mountain village an idyllic integration of humanity into nature, daytime brings cooking fires and the burning of refuse. The villagers are conditioned to the resulting stew of smoke that can linger in the valley, but it registered as noxious and toxic to Anna. 

Some of the refuse is plastic, which we're all told releases toxins when burned. What plastics do the villagers have if they grow their own food and have few possessions? Though they cook delicious meals most days, there are times when villagers may not feel like cooking, and so pull out store-bought noodles and tomato sauce, the plastic wrappings from which end up getting burned in the refuse pile. 

This is not much different from my own experience growing up in a small village in Wisconsin in the 1960s. One of my chores was to burn the garbage, plastic and all. In autumn, we'd rake some leaves into piles to jump into, and others into piles to burn. We'd toss acorns into the glowing core of the fire and wait for the popcorn-like explosion. On brisk, sunny fall days, the whole village became suffused with what registered as a sweet and endearing aroma of burning leaves. Even after moving to a city, the 1930s house we moved into had an incinerator in the basement for burning trash. And in the 70s and 80s, when I played jazz gigs in smoke-filled bars, it was not until the next morning that I'd notice the wretched smell of stale smoke in the clothes I had worn. 

There have been efforts to promote cleaner air in remote mountain villages around the world. Some students, before entering Princeton University, sign up to spend a "bridge year" in a foreign country doing good deeds, one of which is helping build cleaner burning stoves for villagers in Peru and elsewhere. You'd think the villagers would be grateful for a home less choked with smoke, and maybe they are, but the capacity of the body to become conditioned to abuse is both impressive and exasperating.

Lots of interesting reading out there on bees. Here's some info about eight species of honey bees around the world.

Wednesday, July 19, 2023

Monarch Butterfly Update -- July, 2023

How many monarch butterflies are people seeing this year? I've seen a grand total of two thus far. Neither paused for a photograph, so this picture is from a past year. 

On July 11, I saw one flying crazily at the Barden. They are expert and often seemingly whimsical flyers, but this one's flight was unusually frenetic. At double the usual pace, it would approach flowers but not land on them, leading me to speculate that it was looking for a mate rather than nectar. A useful Q&A post at suggests that these episodes of particularly erratic flight are induced either by a predator's attack or by a male chasing a female. But the frenetic flight made me instead imagine what it is like for monarchs when their numbers are few, and the search for a mate consumes more and more of their energy. Might a fruitless search at some point become frantic?

A few days later, I saw a monarch in a pasture near Herrontown Woods, flying at a more measured pace. 

There were a few common milkweeds growing in the pasture, but I was particularly happy to discover a couple specimens of green comet milkweed (Asclepias viridiflora), growing there as well. It's a species I've only seen twice in Princeton, the other incidence being a few individuals in the Tusculum grasslands. 

It's common to think that monarchs gain all their sustenance from milkweeds, but in fact the adult butterflies obtain nectar from a broad range of flowers. Otherwise, they would starve after the milkweeds have finished blooming. The caterpillars, however, are highly particular, and will only eat the foliage of milkweeds. The milkweed foliage is around all season long for the munching, though a lot has to happen for the foliage to actually be put to use. A female needs to lay eggs, and those eggs need to elude predation long enough to hatch. I have not seen an actual caterpillar in years, nor much evidence of milkweeds being consumed, but clearly a few are surviving somewhere.

To get a more in-depth report on the status of monarchs, my go-to is the savant Chip Taylor, who blogs at MonarchWatch. In a June 14 post, writing about whether monarchs will be listed as threatened or endangered, Chip Taylor wrote openly about the eventual end of the great monarch butterfly migration. It's believed that the monarch itself is not likely to go extinct, but that the migration--involving the portion of monarchs that participate in the fantastic journey north from the mountains of Mexico up into the U.S. and Canada, then back to Canada in the fall--is increasingly vulnerable. According to Taylor,
"As applied in this case, extinction refers to the loss of the monarch migration and not the species per se. Given the link between the increase in greenhouse gas emissions and increasing temperatures and the world’s slow response to these changes, yes, the monarch migration will eventually be lost."

It's important to note that those who raise alarms about the climate crisis are the optimists. It is optimistic to face up to a grave risk, and call for action to save what will otherwise be lost. Denial and dismissiveness are rooted in pessimism. They take a gloomy view of 1) our capacity to recognize dangers and 2) our capacity to act collectively to prevent catastrophe. Taylor's recognition of the high likelihood that we will lose the migration raises an obvious question, which he hastens to answer.

"If the monarch migration will be lost eventually, why make great efforts to sustain it? Faith. We have to have faith that the world will come to its senses and work collaboratively toward the reduction of greenhouse gases to save the natural systems that sustain us. There is hope. The rate of increase in CO2ppm has declined in recent years."

Another answer is that, the longer the migration can be maintained, the longer humanity has to "come to its senses." 

It is stunning, knowing the extraordinary power of carbon dioxide to influence the earth's climate, that society has left it unregulated. As individuals, cities, and businesses, we remain free to pour as much of it as we please into the atmosphere. Until that giant hole in our regulatory protections is patched, the vast majority of people will not change their behavior. 

Thursday, September 30, 2021

Where Have All the Pollinators Gone? -- Summer, 2021

Wherein is discussed the season's paucity of pollinators, the curiously prolific presence of hornets, and possible causes thereof. 

With the coming and the going of this year's autumnal equinox, it's time to look back on a long summer and ask, "What happened?" Or, more precisely, "What happened to the happening that didn't happen?" 

There's lots of talk about how insects are in decline and that we need to plant more wildflowers to support them. A local ecologist and avid birder, David Wilcove, co-wrote an oped in the Washington Post about the danger posed by insect decline, and the need to better monitor populations, as is done with birds.

In past years, a summer's climactic buzzfest on the boneset

This year, there was a steep decline in pollinator numbers in Princeton. Each year I grow a banquet of wildflowers in my backyard for all manner of insects to feast upon. In past years, they'd come from near and far, their numbers building through summer, climaxing in late August in a buzzfest on the boneset. Though mountain mint is another great draw for insects, in my yard it was boneset in particular, clustered here and there in the garden, that in past years drew the multitudinous shapes and sizes of the insect world. Its broad disks of tiny white flowers seemed like a Serengeti in miniature, an open plain perched conveniently four feet above the ground, teaming with life. It was a chance to see the insects close up, they being so focused on the nectar or each other that they took little notice of me.

Then, two years ago, and again last year, the numbers of insects were down--still numerous but not enough to stir that late-summer's jazzy feeling of frenzied activity. 

2021: An astonishing diminishment

And this year? This year, boosted by the rains, the wildflowers grew to fabulous size. Broad arrays of blooms mounted on multiple stems stood at the ready. In early summer, while periodical cicadas held center stage, the numbers and variety of pollinators were building nicely. 

But then, as the wildflower meadow's heavy hitters--the cutleaf coneflowers, Joe-Pye-Weeds, bonesets and wild sennas--unveiled their fabulous blooms for the mid-summer festival of nectar, the insects were no-shows. Abundant flowers had few pollinators, and sometimes none at all. Diversity dwindled to some tiny somethings, a few bumblebees and even fewer honey bees. 

Sifting through possible causes for the decline

Possible causes for the dramatic decline have been offered: extreme heat, more homeowners fogging their yards for mosquitoes, expanding monocultures of lawn and invasive species. Or perhaps the climate-changed winters have messed with insect dormancy.

The rains of July, the rains of August

What I have particularly noticed over the past three years, however, is the increase in rain during the summer. Rutgers precipitation data for NJ show increased precipitation particularly over the past two years in July and August. Not only has there been more rain, but the intensity of the rain has increased. The sound on the roof is different--one can hear and even feel the extraordinary density and weight of the rain. The deep trauma of Hurricane Ida was the climax among multiple intense storms before and after. The ground and foliage are literally getting beaten up by these deluges. Insects try to hide during storms. Some live in the ground. The harder the rain, the fewer places to hide, and the more likelihood that a ground nest will be flooded out. All that sustained moisture could increase the risk of disease, which an entomologist friend says can play a big role in bee numbers. 

Some of us noticed other changes as well. Gladly, the numbers of odorous house ants invading our kitchen were down from previous years. Mosquitoes in our area seemed relatively rare in early summer, though numbers surged later in the season--tiny ones, probably asian tiger mosquitoes. 

A proliferation of hornets

What was most striking and very strange was a proliferation of hornets. Last year, I seldom saw them, but oftentimes this summer, approaching a patch of flowers, the first thing that would catch my eye was not pollinators but the hornets that can prey upon them. 

We have two kinds of insects called hornets. One is the European hornet, which looks to me like a stocky bee--black markings with a particularly thick yellow abdomen.

The other is the bald-faced hornet, a native insect with black markings and a whitish face. 

Both are hard to photograph because they don't land, but instead keep cruising around the flowers. Periodically they may bump into a bee that was minding its own business on a flower. The contact lasts a split second, then the hornet flies on. The purpose of this brief harassment is not clear. 

Here's a bald-faced hornet in adult and larval form, found on a fragrant of nest someone left at the curb. Both kinds of hornets live in nests that are in or hang from trees. The paper they make, by the way, is beautiful when looked at close up.

Why the proliferation of hornets, cruising relentlessly among the flowers with a sense of urgency but no clear goal? Maybe they just seemed more numerous due to the lack of other insects to catch one's attention. Or maybe the fact that they live in elevated, waterproof nests allowed them to better survive the intense storms. 

The seeds of change planted over centuries

In any case, this summer was not the lively pollinator party I was used to playing host to, both in my backyard and at our Botanical Art Garden (the "Barden") in Herrontown Woods. One interpretation is that the carbon dioxide we've been scattering to the winds is now coming home to roost, in the form of weird winters and intensified storms. In Princeton, basements flooded that had never flooded before. It's not a stretch to hypothesize that many bees also find themselves newly vulnerable to the merciless power of the rain. And then, on the sunny days when pollinators can make it to the flowers, there's the haunting background of patrolling hornets.

In a docile wasp, some small comfort

As students returned to the university, I remembered helping my daughter move in to Whitman College two years ago. In the courtyard, I had noticed thousands of wasps cruising just above the grass. It was a mating dance, of no danger to the parents and students passing by, of blue-winged wasps. I had recognized their distinctive orange abdomen from those that would frequent the flowers in my backyard, a mile away from campus. 

This year, I had seen only one in my yard, and wondered whether their improbable annual ritual was still playing out at Whitman College. 

What I found on Sept 2nd were perhaps a hundred wasps flying in their usual criss-cross manner a foot above the lawn. Some seemed fatigued by it all, and would abandon their flight to sit among the grass blades for awhile. Though their numbers were down from the thousands I'd seen two years prior, I was glad to see any at all. And a student sitting in a lawn chair, scrutinizing his computer, told me there had been many more ten days prior when students first began moving in. 

It would be nice to think that the paucity of pollinators I observed this summer was an isolated affair. But others around New Jersey have made similar reports. An entomologist friend who lives in Oregon told me that he's seen "a very significant decline in pollinators" this year, probably due to drought, though he also said that each species can vary in numbers year to year. 

An ark is built of something more than flowers

We take so much for granted in our lives. When something breaks, that's when one has to study up and figure out how it works, what went wrong, and how possibly to fix it. The insect world has been taken for granted since forever. Annual bird surveys benefit from a community of avid birders, but citizen scientists who are up to speed on the mind-boggling diversity of insects are fewer to come by. We thought we could just plant some flowers and the insects would come, but the needs appear to be far deeper than that. 

Thursday, September 09, 2021

A Summer-Long Residency of Paper Wasps in My Window

Our house is solid, but for some reason there is one storm window that is slightly out of square--just enough that the storm window can't be fully closed. And through that small crack each spring come paper wasps, not to enter the house but to build a nest in the space between inner and outer windows. It starts with a queen--a kind of homesteader, or who in the business world might be called an entrepreneur. I haven't watched closely enough to see if she uses last year's honeycomb of cells or builds new, but at any rate she does the early work herself, as if starting a colony, or a small business, until she can raise young to do most of the work for the rest of the summer. Occasionally I'd take a look to see how they were doing.

The most common species of paper wasp, it turns out, is originally from Europe. A simple distinction between bees and wasps is that bees are vegetarians and wasps are carnivores. Bees raise their young on protein-rich plant pollen, while wasps feed their young other insects. 

My best guess as to what's going on in this picture is that the three wasps with their abdomens sticking out are feeding the young by delivering them food in their chambers. When ready, the larvae cap their chambers, pupate, and then eat their way out as fully formed adults. 

Some types of insects, like butterflies and cicadas, have to remain still after emerging, to let their wings slowly expand and dry. But these wasps emerge with their small, narrow wings ready to go. You can see one of the new wasps at the bottom of the photo, emerging like a chick from an egg. 

One day in July, I heard a scuffling sound at the window, looked up, 

and saw a bird balancing on top of the window. 
It was a red-bellied woodpecker--a bird named after a part of the body one almost never sees, rather than the red hood that is so distinctive.  From its precarious perch just above the crack in the window, it could use its keen eye, flexible neck, and lightning quick reflexes to snatch any wasps coming or going.
Sometimes it stuck its beak right in the crack, as if my house were a tree. 

Finally, the bird noticed me and flew off. Whether this was a singular visit or one of many, the wasp nest was considerably diminished and never regained its earlier hustle and bustle. By the end of August the nest stood empty, which meant I could now open the inside window again.

There are many questions to ask. Do the wasps feed their young regurgitated insect puree, or do they serve sliced and diced versions? Inquiring minds want to know. I spent some time trying to figure out which one was the queen. No wasp stood out as distinctly different from the next. Some of the wasps on the nest were vibrating their abdomens. Others were not. What does this mean? And what impact do the paper wasps have on my garden? Are they responsible for keeping my kale unexpectedly free of caterpillars, and if so, do they nicely limit their diet to garden pests, or are they also preying on the rarer sorts of butterflies and moths we wish there were more of? 

I found a few answers at this Galveston County master gardener site. Here are some excerpts:

Adult paper wasps are efficient predators, mostly of caterpillars. They carry them back to the nest and feed them to the developing larvae. They will collect large numbers of caterpillars from the area around the nest during the course of a season. Adult wasps typically prey on a wide variety of caterpillars including corn earworms, armyworms, loopers, and hornworms. Adult wasps also utilize beetle larvae and flies as food for their young..

Adult paper wasps primarily feed on nectar or other sugary solutions such as honeydew and the juices of ripe fruits. Adults also feed on bits of caterpillars or flies that are caught and partially chewed before presenting to their young.


In early fall, the colony begins to produce males and special reproductive female wasps. These reproductive females, which constitute next year�s queens, mate with males and soon leave the nest in search of protected spots in which they spend the winter. The remaining worker wasps eventually die and the nest becomes vacant. Paper wasps will not reuse their nests the next year.

Even some websites that are trying to sell products or pest control services have useful info, such as this comparison of paper wasps and yellow jackets

I sometimes think of fixing the window, but I suspect that, come next spring, a lone queen of the paper wasp variety will come along and still find a suitable spot to take up residence. Maybe that's for the best.

Friday, August 06, 2021

More Kinds of Dragonflies and Damselflies Found at Rogers Refuge

What wonderful names have the dragonflies and damselflies that Mark Manning and his son are finding at Rogers Refuge. Known mostly for its birdlife, this patch of floodplain along the StonyBrook below the Institute Woods also is home to other diversities. My ecological assessment of the refuge from 2007 includes a plant inventory, and now we have an expanding list of Odonata as well, totaling 36 different species. Below are the Mannings' photos of a few, and their full list to date. The names make one want to write an ode to Odonata. 

Now Dasher, now Dancer, now Skimmer and Jewelwing!

On, Bluet! on, Glider! on, Darner and Clubtail!

To the top of the sedge! To the top of the cattail!

Now fly away! fly away! fly away all!

The names--Fragile forktail, pondhawk, meadowhawk--are as vivid and full of action as the insects themselves.

Ebony Jewelwing
Blue Dasher
Painted Skimmer
Unicorn Clubtail

Blue-tipped Dancer
Lancet Clubtail

Black-shouldered Spinyleg

Rogers Refuge Odonata List as of 7/17/2021-Mark Manning


Ebony jewelwing

Blue-fronted dancer

Violet dancer

Powdered dancer

Blue-tipped dancer

Azure bluet

Double-striped bluet

Familiar bluet

Turquoise bluet

Stream bluet

Slender bluet

Fragile forktail

Eastern forktail

Common green darner

Comet darner

Unicorn clubtail

Black-shouldered spinyleg

Lancet clubtail

Ashy/dusky clubtail

Prince baskettail

Common baskettail

Halloween pennant

Eastern pondhawk

Slaty skimmer

Widow skimmer

Twelve-spotted skimmer

Painted skimmer

Great blue skimmer

Blue dasher

Wandering glider

Spot-winged glider

Eastern amberwing

Common whitetail

Autumn meadowhawk

Carolina saddlebags

Black saddlebags


Total: 36

Update: at season's end, in early September, the Mannings added one more species to the list: 

the russet-tipped clubtail

Suburban Monocultures and Insect Decline

Thoughts about insect decline and some field observations came together at the corner of Harrison Street and Terhune the other day when I headed to the optical shoppe to get my glasses adjusted. 

The lawn outside the building could be described as an ecological desert, a large expanse of closely cropped grass whose only purpose is to flatter the building. And yet it seems right to our culturally conditioned eyes, which view it as greenspace even if it constitutes an ecological void. 
Whereas a lawn is an intentional monoculture enforced directly by people, this expanse of Sericea lespedeza, also called Chinese bushclover, is enforced by the aggressiveness of the plant itself. I've watched this field, on land next to the shopping center, gradually become overwhelmed by the introduced species, whose foliage is spurned by the local wildlife, including insects.

Thirty feet away, the Japanese stiltgrass is having its way along Terhune, as it does along so many roadsides. This displacement of diverse flora, whether suddenly in the form of a development, or gradually along roadsides or in abandoned fields, surely is playing a big role in the diminished habitat for the insects upon which ecosystem foodchains depend.

Interesting to see the patch of lighter green in this photo. That's native sensitive fern, which is clearly holding its own against the stiltgrass. But this is one small victory in a landscape that has shifted dramatically towards monoculture. Imagine what it would be like to walk into a supermarket and find only cardboard on the shelves. That must be how an insect experiences so much of the suburban landscape.

Note: Just noticed that local birder and Princeton professor David Wilcove recently co-wrote an opinion piece in the Washington Post entitled "We need to figure out what's happening to the bugs--before it's too late."

Tuesday, July 20, 2021

Monarchs and a Mid-Summer Multitude of Wildflowers at the Barden

So, I was at the Barden today, that being the Botanical Art Garden in Herrontown Woods, and amidst all the positive energy of budding flowers I had a cynical thought. There are a couple spots around the Veblen Circle of wildflowers where milkweed has been spreading. Lots of leaves and none of them being eaten by monarch caterpillars--an all too common observation over the years. People say to plant milkweed to help the monarchs, but the monarchs aren't helping themselves to the milkweed. What gives? 

As if on cue, a monarch appeared an instant after I had that thought. Only the third I'd seen this summer, it was checking out the milkweed and other plants growing in the sunny openings of the Barden. There are many kinds of native flowers blooming right now, which I'll show photos of later in this post, but the monarch headed over to one in particular,

a buttonbush, whose tiny flowers form the shape of a golfball--a convenient surface upon which the pollinator can go from flower to flower, sipping nectar. For an insect it must be like an assemblage of Hold the Cone miniature ice cream cones, but no need for a freezer. 

Moments later, another monarch butterfly caught my eye, and this one was showing a more intense interest in the milkweeds. There are two types at the Barden--purple and common. Both kinds spread underground, creating clones with many stems--enough to support a whole gang of hungry caterpillars. The butterfly was landing on the edge of the purple milkweed leaves and dipping its abdomen under the leaf to lay an egg. 
After doing this a number of times, it headed elsewhere, allowing me to take a look. Not easy to see. There, in the lower left. 
Here's an egg a little closer up.

There's actually quite a bit going on underneath a milkweed leaf. Here was a whole cluster, which I'm guessing are the eggs of the milkweed tussock moth--another Lepidoptera that can stomach milkweed's cardiac glycosides. 

Of course, it's a hopeful sign to see a monarch laying those single eggs, but we saw this last year, and it didn't lead to any sightings of caterpillars later on. It's possible the eggs are getting eaten by ants and spiders. A complex food web can have its perils, and it's interesting to note that milkweed that once grew in farm fields (in the days before Roundup-Ready corn and soybeans) might have had better monarch survival due to there being less predators in that simplified landscape. 

Still, we can hope that this is the year when the Barden does its part to build monarch numbers in preparation for their perilous flight back to Mexico in the fall.

Another sweet sight today, again not captured in a photo, was the pair of hummingbirds that landed on a wire cage just five feet away. Hummingbirds, in my experience, actually spend a lot of time perching, which makes sense given how intense is their flight. Their presence was the answer to a question overheard at the checkout counter at the Whole Earth Center: "Has anyone seen any hummingbirds?" Like monarchs, they also have to negotiate a difficult migration every year.

Maybe they were attracted to the tubular flowers of wild bergamot, 

or beebalm, or jewelweed.

What follows here is a documentation of all the flowers seen blooming right now in the Barden, as the midsummer diversity kicks in. After all the work of weeding and planting, there's pleasure in simply walking the paths and appreciating all that is growing so enthusiastically. 

There's a lot to document. These signs, created by Inge Regan, offer four species to look for. When learning plants, it's good to focus on a few at a time. 

For those more familiar, we've brought together some 40 species that bloom in mid-summer, some of them shown below. Maybe you can walk the pathways and see how many you can find. We're trying to figure out how to pot up all the excess and make them available to visitors to take home.

To see some of the other species showing their stuff this time of year, click on "read more", below.

Friday, July 09, 2021

Some Early July Flower and Insect Sightings at Herrontown Woods

Though the bottlebrush buckeyes in this photo have been blooming in the Botanical Art Garden (Barden) for a couple years now, this photo could not have been taken last year. The gazebo in the background is a new arrival as of last December, and the pin oak behind it can be seen heavily flagged this year by the egg laying of periodical cicadas. 

Those features were not the reason for the photo, however, which was taken because of an insect that requires a zooming in to see.

The Bottlebrush buckeye blooms attract clearwing moths, which do an excellent imitation of a hummingbird in appearance and flight.

Another plant named for the bottlebrush shape of its flowers is bottlebrush grass, also blooming now at the Barden. The wind-pollinated flowers of grasses and sedges lack color, but can still be appreciated for their shape. Bottlebrush grass is called a cool season grass because it greens up early in spring and blooms before the depths of summer. Many other native grasses are of the warm season variety, like Indiangrass, big and little bluestem, broomsedge, and switchgrass. Dominating tallgrass prairies of the midwestern states, they get a late start in the spring and grow through the summer, reaching maturity in the fall. (Turfgrasses have the same categories, though the grasses aren't native. Most lawns around here are cool-season grasses, with bermuda grass being a warm season grass that turns brown in winter.)

Though many species at the Barden have been planted, narrowleaf mountainmint apparently found its way in on its own, growing along one of the paths.

Necessary for the prospering of these summer wildflowers is an opening in the tree canopy where sunlight can reach the ground. Though people often equate habitat health with trees, we actively remove many young trees in the Barden that would otherwise grow up to shade out all these herbaceous species that insects depend upon for summer sustenance. 

Because of this active management, you can look up from the Barden and see some open sky--rare in Princeton open space lands.

Growing on its own, in what few openings occur naturally at Herrontown Woods, is a very subtle green-fringed orchid, here protected from the deer by a small cage. 

And what's blooming in summer in the deep forest that makes up the great majority of Herrontown Woods? I found this one tiny flower in a stream. Local botanist Elizabeth Horn helped me identify it as Water-pimpernel--Samolus valerandi in the
Theophrasta Family. 

The take-home lesson here is that woodland openings are important for summer biodiversity. Given the lack of natural disturbance by wildfire or the long-gone megafauna, it's up to us to create and sustain it. 

Tuesday, July 06, 2021

The Dragonflies and Damselflies of Rogers Refuge

I still remember the astonishment I felt when I first climbed the observation tower at Rogers Refuge in Princeton, and looked out upon this vista, so unlike anything else in town. This expanse of cattails and wild rice, long valued as a birding mecca, remains a gem primarily due to the work of a small group of volunteers, currently led by Lee and Melinda Varian. Grants from the Washington Crossing Audubon help keep invasive species at bay, and Laurie Larson has compiled the site's history and features at, including lots of bird info and an ecological assessment I did back in 2007.

This summer, Hopewell Valley science teacher Mark Manning and his son are working on a new list for Rogers Refuge, this time of Odonata, a.k.a. dragonflies and damselflies. Mark's knowledge of nature is broad and deep, as became evident during a wonderful walk he led at Herrontown Woods a couple years ago. Below is a preliminary list of species he and his son have found during their explorations this summer. The photo is of a black-shouldered spinyleg.

Rogers Refuge Odonata List as of 6/26/2021-Mark Manning

Ebony jewelwing

Blue-fronted dancer

Violet dancer

Powdered dancer

Blue-tipped dancer

Double-striped bluet

Familiar bluet

Turquoise bluet

Fragile forktail

Eastern forktail

Common green darner

Comet darner

Unicorn clubtail

Black-shouldered spinyleg

Lancet clubtail

Common baskettail

Eastern pondhawk

Slaty skimmer

Widow skimmer

Twelve-spotted skimmer

Painted skimmer

Great blue skimmer

Blue dasher

Eastern amberwing

Common whitetail

Carolina saddlebags


Total: 26

Thursday, July 01, 2021

Spotted Lanternflies at the Barden

While periodical cicadas have been the most noticeable insects at the Botanical ARt garDEN in Herrontown Woods, the nymphs of spotted lanternflies have been congregating quietly on a few select plants. Our observations confirm what's widely stated, that the spotted lanternflies prefer to spend their quality time on Ailanthus, also known as Tree of Heaven, a tree introduced long ago to the U.S. from Asia. 

I've been going around, cutting the sprouts of the Ailanthus in an effort to at least discourage the lanternflies' favorite plant.

Another asian species, the ever so spiny Japanese aralia, is also attracting a few of the lanternfly nymphs, but not nearly as many. That, too, gets cut to the ground.
Princess tree had none, though it too hearkens from east Asia. You may notice this species making dramatic, large-leaved root sprouts along the canal and elsewhere. Scroll down at this post about towpath wildflowers to see a photo of a princess tree's root sprout's improbable growth.

All three of these nonnative species persist in the Barden as sprouts that we cut down. It would be nice to think that reducing the number of ailanthus and Japanese aralia will discourage the lanternflies as well. 

Among native species the spotted lanternfly is attracted to, a friend has a grape vine that is attracting a lot of lanternflies. She tricks the nymphs into jumping into bottles of soapy water. 

Here's a post from last August with more info on the lanternflies