In an earlier post I pondered what lay within a silky tent strung between segments of chicken wire. A butterfly larva? Or as one reader opined, perhaps a paralyzed caterpillar, soon to be devoured by a spider?
While I wasn’t looking, the caterpillar — which was very much alive and not on anyone’s menu — continued to spin its magic and metamorphosed into a shiny cocoon.
Sunlight on silk. Took a closer look. Hey, somebody’s in there!
Caterpillar. Butterfly. In. Waiting.
Watched this rock-a-bye baby for several days but saw no further change. Perhaps I’m just hasty. Time will tell the story.
I wrote recently about The Silk Road. This is the rest of the story.
How many mouths does it take to eat a tree? Not the wood. Just the leaves. All of them.
That’s what has happened in our corner of the world. Most of the aspen poplar have been completely defoliated by armies of small black caterpillars.
The caterpillars, or larvae, are the second stage in the life cycle of the Large Aspen Tortrix. The name Tortrix comes from a Latin word meaning to twist. When you see the leaves they’ve been feeding on, you can see why that name was chosen.
These photos and captions tell more of this tale …
Aspen defoliated by caterpillars of the Large Aspen Tortrix. The other leafy trees are balsam poplar which are mostly unaffected.
The start of the infestation — larvae have eaten much of the leaves.
Larva on a spruce branch. Strong winds and the search for more food sent larvae groundward on strands of silk. This one landed on a spruce tree.
Larvae that weren’t able to find poplar leaves to pupate in settled for spruce.
Tortrix larva beginning to spin silk on a poplar leaf in readiness for the next stage in its life cycle.
This larva is spinning silk on a balsam poplar leaf, drawing the leaf sides closer together until it is completely hidden. It will hide there, turning from an active leaf-eating caterpillar into a non-feeding pupa, the next stage in its life cycle.
Here’s an interesting grouping (L to R): a fully formed pupa, the larval skin it shed as it pupated, and a caterpillar beginning its transformation.
Some pupae have already split open, releasing the adult moths. I imagine we’re in for quite a show when the big hatch happens.
We’ve had defoliations in the past, but I don’t recall anything like this — it stretches for kilometres in all directions.
Although this feeding frenzy sounds disastrous for the aspens, it’s not as gloomy as one might expect. The trees are already sprouting new leaves and before long will look more like they should at this time of year.
Conditions this year are different. Winter was mild. Spring came early. It turned hot. Rainfall has been little and sporadic. Are we seeing the effect of climate change? Or merely a brief climatic blip?
It’s an ongoing evolutionary dance as we each strive to adapt to our world.
Large aspen tortrix Choristoneura conflictana
White spruce Picea glauca
Trembling aspen Populus tremuloides
Some times Ma Nature slaps you up the side of the head. Just to make sure you’re paying attention.
She did it to me this morning. I was wandering through our woods, head down, looking for flowers. Not much luck. Sigh.
As I moved from shade to a small sun-lit glade I looked up. That’s when she smacked me.
It was breath-stopping.
The entire glade, every tree — twig, branch and trunk — was festooned with silk threads shimmering in the light, as though they were alive.
Up. Down. Sideways. Loops, lines and clumps. Draping from tree to tree, like some great aerial road map.
I stared in disbelief. Minutes passed before I remembered my camera.
I took nearly a hundred shots though none comes close to capturing the awe I felt. But that’s okay. It was, truly, unforgettable.
As for the silk makers?
Their story is to come …