May 2008

tent caterpillar on black birch trunk

Let their habitation be desolate; and let none dwell in their tents.
Psalm 69:25 (KJV)

Eastern tent caterpillars (Malacosoma americanum) are a common sight this time of year, especially in their last instar, after they abandon their tents. They stray onto the porches and wander over the furniture, looking for protected places in which to pupate. On a visit this past Monday, my three-year-old niece Elanor decided that they were cute — not typically my own reaction — and began petting them, prompting the caterpillars to arch their heads back like housecats. Yesterday afternoon, I watched one crawling up the neck and across the face of a box turtle, which merely shut one eye while the caterpillar took its measure.

tent caterpillar tree (black cherry)

The tents began appearing at the end of April in unusual numbers, especially on black cherry trees, which are the favorite food source for tent caterpillars and occur in unnatural abundance across Pennsylvania due to 150 years of clearcut logging practices and the reversion of old fields and pastures. Black cherry is a common first-succession tree species in many forest types, and thanks in part to its relative unpalatability to white-tailed deer, it can form almost pure stands in many areas that would have formerly hosted oak-hickory, beech-hemlock, or mixed deciduous forests. Here in Plummer’s Hollow, many of our southeast-facing slopes are dominated by black cherry stands, and I figured they’d be completely defoliated by this time.

blossoming black cherry

Instead, Sapsucker Ridge is white with blossoms, filling the air with an ambrosial scent. One finds only a few black cherries as badly defoliated as the one in the second photo; the tree above is more typical. Though dotted with tents, only scattered branches have actually been stripped of their leaves.

dead tent

A closer look reveals that most of these tents are filled with dead caterpillars. The few still alive twitch spasmodically. What happened? I’d guess that the unusually cold, wet weather over the past few weeks is at fault. Nighttime temperature routinely dropped into the low 40s this month, and sometimes even into the high 30s; daytime temperatures rarely exceeded the mid-50s; and rain was almost constant for the first three weeks of the month. Not only would the cold have shut down their temperature-sensitive digestive systems for prolonged periods, but the rain would have kept them confined to their silken tents, and the two together would’ve made them much more susceptible to starvation and disease. According to the Wikipedia article on tent caterpillars,

The tent is constructed at a site that intercepts the early morning sun. The position of the tent is critical because the caterpillars must bask in the sun to elevate their temperatures above the cool ambient temperatures that occur in the early spring. Studies have shown that when the body temperature of a caterpillar is less than about 15 °C [59 °F], digestion cannot occur. The tent consists of discrete layers of silk separated by gaps and the temperature in these compartments varies markedly. Caterpillars can adjust their body temperatures by moving from one compartment to another. On cool mornings they typically rest in a tight aggregate just under a sunlit surface of the tent. … Later on in the spring, temperatures may become excessive at mid day and the caterpillars may retreat to the shaded outside surface of the tent to cool down.

Entymologist Vincent G. Dethier’s wonderful and evocative classic, The World of the Tent-Makers: A Natural History of the Eastern Tent Caterpillar (University of Massachusetts Press, 1980) describes in Chaper 13 (appropriately enough) the battery of predators and diseases that keep this native insect in check. He details the spread of a deadly virus from colony to colony, then adds:

As if that were not enough the unusually wet late spring had been kind to molds, mildews, smuts, blasts, and bacteria. A particularly virulent spore-forming species of bacterium struck many of the colonies. … The enormous population of tent caterpillars had been cropped by weather, starvation, ants, bugs, parasites, fungi, viruses, bacteria, and misadventure in general. It had been a particularly trying year. Summer had hardly begun and the die had already been cast for the year to come. There would be fewer moths, fewer egg masses, and fewer colonies of the next generation.

So a spring that spells bad news for many farmers is good news for the wood products industry, which relies heavily on black cherry in Pennsylvania. Unlike fall webworms, which come too late in the season to have much of an impact on the trees they defoliate, tent caterpillars can greatly stress the trees they defoliate during their periodic outbreaks.

As global climate change plays hob with our weather patterns, it will be interesting to watch the effects on insect outbreaks, and over the long term, on forest succession. For example, if black cherries continue to predominate as many foresters would like, more-frequent icestorms would have a much greater impact than they would if less brittle species such as red oaks and tulip poplars took their place. Warm winters are said to promote the spread of pest insects, but what about warm winters followed by cold springs? I’d heard that the state was due for some pretty large gypsy moth outbreaks this summer as well, but here in Plummer’s Hollow, at least, their caterpillars are few and far between.

Cross-posted to the Plummer’s Hollow blog.

This entry is part 7 of 14 in the series Public Poems

 

Abandon hype, ye who enter
these sound-proofed rooms:
you can fight City Hall all you want, really,
provided that your words
are bland as water & promise
jobs—drip—development—drip—growth—drip.
Open bribes will not be tolerated.
The voters expect transparency
& paper trails, sometimes even
the anodyne of a Town Hall meeting
where one by one they can stand
& state their names for
the record, that stagnant pool
that reflects everything
but their weariness, their anger,
the way their hands rise
like saprophytic flowers toward the sun,
their touching gratitude at finally
being recognized to speak.

Smorgasblog is back, at least for the time being, and has taken the place of the Google Reader-generated automatic list of recent posts from my blogroll in the right-hand sidebar. Except when I screw up and forget to categorize an item as “smorgasblog” before publishing, these link-and-quote posts will not show up in the Via Negativa feed; you’ll have to visit the blog to see them, as before. The difference this time is that I’m not coding everything by hand, but am instead using the Sideblog plugin from Kates Gasis. I currently have it set to display 10 posts at a time, and have included a link to the category archive in case you get behind.

I ended the original incarnation of Smorgasblog after a year and a half because I found it too time-consuming, especially as qarrtsiluni became more labor-intensive. I’m hoping this stripped-down, easier-to-maintain version won’t be such a distraction, and I’m planning to update it in a less thorough, more lackadaisical fashion than before. We’ll see how it goes.

The specific impetus to resume smorgasblogging today came from reading recent posts at Velveteen Rabbi and frizzyLogic and feeling an overwhelming urge to steal a little bit of their magic. So blame the Rachels, frizzy and velveteen, for blogging too well!

UPDATE: Unfortunately, it appears that the latest version of WordPress (2.5) has a bug which prevents me from excluding next and previous posts belonging to a given category (in this case, Smorgasblog) from the navigation links on single post pages. So while Smorgasblog posts won’t appear on the index page or in the Recent Posts sidebar listing (thanks to Rob Marsh), they will interrupt the flow for those who navigate from post to post, for the forseeable future.

This entry is part 6 of 14 in the series Public Poems

 

The doors swing
both ways; be careful.
From either side,
the other looks like out.
This mystery your body
is like a Klein bottle,
all surface, no way in.
From the inevitably
flawed models, it appears
to intersect itself:
it dwells within the without.
That’s why the wind —
or is it breath? — can’t
be held, & you need
a fourth dimension
to lose those edges
called sickness,
to become whole.

This entry is part 5 of 14 in the series Public Poems

 

To enter fully into another’s words
is to leave your own fixed residence,
part coffin, part cocoon.
The walls fall away.
Letters the color of night
swell with sirens & the call
of the whip-poor-will.
Out in the open book,
anything can happen except sleep.
Dreams may be redeemed
for a small deposit.
This is why, in the public library,
everyone is homeless.

This entry is part 4 of 14 in the series Public Poems

 

Veterans beware: remembering is a form of lying
at which politicians and war-mongers are especially adept.

Flag-burners beware: the U.S. Flag Code identifies fire
as the only proper & respectful way to dispose of a flag.

War memorial builders beware: pigeons are a kind of dove.
Whatever you do, they will have the last say, & it won’t be pretty.

Readers beware: all poets are traitors.
This poem was written from the prison of a bad conscience.

This entry is part 3 of 14 in the series Public Poems

 

Attention suicides: please have the consideration
to drown elsewhere. It is not that your body
would be especially toxic — that’s a myth.
But what we crave in water is an absence of taste,
not the taste of absence.

Also, kindly make sure your water bill is paid up.
It’s the least you can do for your neighbors,
who will soon probably be needing to recharge
their own reservoirs, those brown or blue pools
in which on occasion you may have glimpsed yourself,
smaller than life.


Scherzo for Winds, from the Undiscovery Channel

While I stand still as a gnomon trying to shoot the wind, five, six, seven chimney swifts wheel over the treetops up on the ridge, seining the air for wind-borne invertebrates: gypsy moth caterpillars on one-strand parachutes, perhaps. Baby spiders no bigger than an 8-point asterisk. Anything with wings.

A turkey vulture loses altitude above the corner of the field, rocking from side to side on upcurved pinions. Will it have to flap? No. It enters a thermal at last and spirals upward.

A common fritillary weaves drunkenly past my right shoulder, seemingly unconcerned by the sudden strong gusts throwing it off course. (Does it have a course?) I think a new verb is called for: it serendips.

From time to time, maple seeds come helicoptering in and disappear into the tall grass. The evidence of past years’ red maple profligacy dot the field, seedlings just big enough for the deer to find.

A sharp-shinned hawk sails out of the woods next to the powerline only to hover forty feet above the roiling sea of grass, wings fluttering rapidly, and then fly back. A cloud slightly larger than the others brings a spit of rain.

This entry is part 1 of 14 in the series Public Poems

 

A reckless poem crushed between ads —
there’s nothing to see here, folks.
Keep moving.

__________

I’m not done writing tool odes, yet, don’t worry! I just got this other idea for what will probably be a shorter series — poems to be placed in public spaces, written with an awareness of their contexts. I’d welcome suggestions of other locations for these poems.

For examples of actual public poems, see the archives of NYC’s Poetry in Motion project, the Pennsylvania Center for the Book’s Public Poetry Project, and especially the CityPoem World Index at the New Urbanist website ErasmusPC.