One day last week a woman came into the office carrying a cardboard box and asking if there was a biologist around.
Last time something like this happened, the box contained a baby bat, but thankfully this time it was just a mysterious insect nest… thing… on a pine branch. I’m more or less the closest thing to a biologist in our office, so I took a look. I had no idea what it was, but I was pretty sure I could find out, and I used my phone to take a couple terrible photos.
Then, I turned to the number one tool of a naturalist in need of ID help: Twitter.
Yup, I took shameless advantage of my entomology contacts on Twitter – again – and in less than forty-five minutes I had an answer. This is a nest built by the caterpillars of a pine-munching moth, and that stuff it’s made of is frass, or caterpillar poop. The next day I ran into the woman who’d brought it in and told her, and she was very interested, if a little repulsed.
Social media: it’s not just for posting photos of what you had for lunch. It’s also for posting photos of balls of caterpillar poop.
Over the weekend a friend and I checked out a stand of trees that burned back in May. It wasn’t a natural forest, rather a plantation of red pines, but forest fires aren’t nearly as common here around the Great Lakes as they are out west and it was interesting to see up-close what woods look like in the aftermath of a fire. Because this particular fire only burned for a few hours, the trees are still standing, but they are mostly dead and dying with blackened trunks.
In some spots a lush carpet of grass and ferns had sprung up, probably in response to the burst of nutrients the fire released.
Wood-boring beetles are slowly working on demolishing the standing dead trees, and we could literally see and hear the process. Sawdust slowly drifted through the air around us and settled at the bases of the trunks.
Most amazing of all, we could literally hear the sound of the beetles chewing and gnawing all around us. Listen!
At the edge of the stand of pines a fire break was created to keep the blaze contained, and the contrast between burned on one side and not-burned on the other was sharp.
Not a bad way to spend a Saturday morning!
As you drive through Rocky Mountain National Park you see a lot of mountainsides (started to type hillsides and corrected myself!) that look like this.
I admit to increasing the color saturation on this photo slightly to bring out what I want you to see, but the large swaths of red-brown trees are obvious regardless. Something is attacking and killing large numbers of lodgepole pines. The culprit is the mountain pine beetle, Dendroctonus ponderosae.
The dead and dying trees are everywhere you turn.
Pine beetles are native to North America, but droughts and warm winters (likely due to global warming) have led to an unprecedented explosion in their numbers. They infest a pine tree by laying their eggs under its bark, which introduces a fungus into the tree that blocks water and nutrient transport as well as the flow of the sticky pitch, with which the tree might otherwise defend itself. (This is actually similar to how the invasive ambrosia beetle, which I’ve written about previously, attacks bay trees.) Apparently this leads to characteristic blobs of pitch forming on the surface of the bark, and if I’d known that I’m sure I could have found examples to photograph but I didn’t know what I was looking for while I was there.
One of the more effective management techniques is to remove affected trees before the beetles can spread, and we saw some places in the national park where tree removal had been taking place.
Unless something changes, this epidemic could continue indefinitely. Very sad.