Tag Archives: borer

Dead wood, ashes.

One of Shakerag Hollow’s giant trees has fallen. An ash that until last week held its arms in the highest reaches of the canopy now sprawls across the forest floor, its body utterly torn. I’ll go back soon and “measure” things (how tall? what weight of wood came slamming down?), but for now: just awe.

I did not see the fall, but came by soon after. The trunk was … indescribable. Some grand words are needed, for barely imaginable violence had been at work. Rent asunder!? The whole wide trunk was twisted and split open, lengthways, in several long gashes. Other trees, themselves no mere saplings, were smashed into the ground. Large boulders were shifted as roots reared and cracked. The air was infused with the odor of fresh-split wood. An overtone of bitterness, like cut oak, but mostly a sweet smell, almost honeyed.

I found the tree in the morning and returned in later in the day for another look. As I stepped closer in the warm afternoon, I hesitated then held back. There were wasp-like creatures, big ones, swarming over one of the thick exposed roots. These insects were scurrying, flickering their wings, crawling over each other. A frenzy.

Black with bold yellow stripes. Buzzing as they flew. Had the tree fall unearthed a buried wasp nest?

Neoclytus caprea

But something was not quite right about these wasps. I moved forward slowly and saw their fat hind legs, too beefy for a wasp. Crickets? No. Then the wing cases, striped in black and yellow: beetles! Wasp-mimicking beetles of some kind. I moved to the side of the tree and saw hundreds of them, racing up and down the bark. They were on no other trees nearby. Half of the beetles were copulating; the other half seemed intent on colliding with the mating pairs. Even though I now knew that they were harmless, their waspy nature made me cautious. Even their short curved antennae were creepily hymenopteran in style (oh yes, those hymenoptera have style).

Who were they? To identify them, I spent some time in the online funhouse known as the Photographic Atlas of the Cerambycidae of the World. This is an amazing site devoted to a single family of beetles, the so-called longhorns (although many of them do not have long antennae). The family contains twenty thousand species, an impressive number when we remember that there are fewer than six thousand mammal species. Some of these cerambid beetles run afoul of humans when they bore into trees and wood that we’d rather they stayed out of. A few of them are “invasive exotics,” killing off native plants. But the beetles in Shakerag were natives: Banded Ash Borers (Neoclytus caprea (Say) 1824). They have an interesting life history, finding recently downed ash and oak trees, then laying their eggs in the bark. The larvae then chew on the wood below the bark, emerging next spring to start the hunt for a newly downed tree.

So I was not the only creature in Shakerag following my nose to the smell of ripped up wood. How many huge ash trees have fallen lately? Not many. Every banded borer within miles must have been at this party. Those flickering antennae are surely tuned to the chemical particularities of newly opened ash wood.

The beetles were one of the very first arrivals in the tree’s new existence. When a large tree falls, its ecological life still stretches out into the future. Perhaps half of the animals (and many more of the fungi) that the tree will nurture during its existence arrive after the tree has fallen. The ecological vitality of a forest can be judged by how may large trees are lying around, feeding beetles, hiding salamanders, growing fungi.

To paraphrase Mr. Faulkner, “Dead wood is never past, it’s not even dead.”