northeast-flora-and-fauna

Last spring I saw  Baltimore Orioles in this general area though I only got pictures of this individual. This fella would sing a bit , fly to another branch, sing a bit more, and repeat this process.  The activity was near Duke Farms' Hay Barn, up in the American Sycamore and London Plane trees. As birds that will eat Eastern Tent Caterpillars [1], there was an abundance of food nearby. On the other hand Orioles enjoy a balanced diet that includes fruit, and this immediate area doesn't strike me as rich in berries and other fruits [2]. May 3, 2023 at Duke Farms Photo 278556535, (c) jpviolette, some rights reserved (CC BY-NC) [1] I'm pretty sure they eat these caterpillars when the caterpillars leave their tents to forage for food. [2] Depending on how far they're willing to go for a meal, raspberries, blackberries, and grapes would probably be available later in the year.

Here's another rabble [1] of Eastern Tent Caterpillars . Few caterpillars are as social as Eastern Tent Caterpillars. They spend their non-feeding time crowded together in the silken "tents" they spin, and leave their tent together to go out to eat about 3 times a day [2], then return together to the tent to rest up and work on their tent [3]. These social caterpillars may be more like family than friends. Late in the preceding spring or early in the preceding summer, their moms laid 200-300 eggs. They'll overwinter in their eggs, hatching the following spring. I suspect that if 2 moms laid their eggs in the same vicinity their kids could hatch and team up on a tent, but there's almost certainly a lot of brothers and sisters squirming around in those tents. In early spring when it can still be chilly, their tents function as mini-greenhouses, helping to keep the caterpillars warm enough to digest food. When temperatures warm, the caterpillars sometimes need to han...

Earlier this spring some wooded areas were inundated with the tent-like webs of the Eastern Tent Moth  caterpillars These caterpillars are native to North America, and prefer to feed on apple, crabapple, and cherry trees, though they're not extremely picky eaters. When I was a kid, we mistakenly thought these were Spongy Moth caterpillars, an invasive pest you probably knew by a different name . As an invasive species, the Spongy Moth caterpillars are probably more destructive of the 2 since they have fewer natural predators or parasites. Although the Spongy Moth does make silk, it never makes the tent-like webs found on trees. It sounds to me like tent moth caterpillars are less likely than Spongy Moth caterpillars to damage trees, at least partly because they eat leaves in the spring when trees are better able to regrow their leaves, and partly because they do have plenty of natural predators/parasites in our ecosystem so their populations don't generally get as large. When...

Some caterpillars are usually seen in large numbers (like Armyworm Moth caterpillars and Eastern Tent Caterpillars ), while most are more solitary. The Milkweed Tussock Moth caterpillars (more about them are here ) seem to be slightly social. I'll sometimes see them alone, but more often I'll see them in groups of 2-9 members. In the 1st picture below, you can see there is a clear size difference in some of these individuals. I'm almost certain the little one in the middle is in an earlier instar than the others (though they lack the colorful tufts of fuzz in their earliest instars). August 31, 2021 at Washington Valley Park Photo 167477945, (c) jpviolette, some rights reserved (CC BY-NC) In the picture below, it's clear that these caterpillars don't require a lot of personal space. August 31, 2021 at Washington Valley Park Photo 167477979, (c) jpviolette, some rights reserved (CC BY-NC)

Here's a silk nest of the Eastern Tent Caterpillar . What it is not is a group of Gypsy Moth caterpillars [1]. Both of these species grow up to be moths, and both have the potential to defoliate our trees by eating leaves, but that's about where the similarities end: They're not closely related. Eastern Tent Caterpillars are a native species that our local ecosystems have been dealing with since pre-colonial days. Gypsy Moths are an invasive species brought here in a misguided attempt to create a silk industry here. Eastern Tent Caterpillars can defoliate trees, though this typically occurs early in the growing season and our trees typically refoliate in a couple weeks. Gypsy Moth caterpillars are more likely to defoliate trees, and the trees are less likely to regrow leaves that season. Eastern Tent Caterpillars create the silk "tents" (hence the name) to provide themselves some (imperfect) protection from predators and the elements. They are fairly social as la...