galls
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Back to the Galls
The hickories and their Caryomia genus midges continue to catch my eye. I’ve now spotted eleven species in Green-Wood, mostly on pignut (Carya glabra). Here’s my first report on this phenomenon. Above is Hickory Peach-haired Gall Midge (Caryomyia persicoides) according to my gall sensei on iNaturalist. Some species are obvious, others like this one need…
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Midge Monday
It turns out, because you have to turn the leaflets over, that hickory trees are potentially loaded with gall mites. There are several dozen hickory gall midge species in the Caryomyia genus, each forcing the tree to make a little shelter for the mite. Acting on a call from a curator on iNaturalist, I examined…
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More Galls
I found a mother-of-gall tree! A red oak, Quercus rubra, in Green-Wood. This tree was probably brought in as a sapling a few years ago. I wonder where it was raised? Could it be that the gall-making species came in with the tree, as we’ve seen with lichens transported into the city on saplings destined…
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Monday Galls
Gallia est omnis divisa in partes tres… At the tips of a young oak, small round nestled in filamenty nests. Galls (not Gauls, pace Casesar) with exit holes. Big question in the wonderful world of galls is: what emerged, the gall inducer or the inquiline (parasite)? Not just on the bud tips. Possibly something in…
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Galls Again
Yes, it’s time for a Fall Gall edition. These are the structures created by the tree, in this case, in response to insects (in these cases) who lay their eggs on the tree. This one is, I think, a Hedgehog Gall. Not sure on this species. Nor this. This one was much smaller and looked…
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Gallish
Went on a walk last weekend in Central Park in honor of Alexander Von Humboldt and the late mycologist Gary Lincoff. We met at the Explorer’s Gate, next to the Humboldt bust. The baby vomit stench of ginkgo fruits, rotting and crushed on the sidewalk, deterred us not. The venerable American elm behind Alex reaches…
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Same Oak, Different Gall
Looking a bit like mushrooms, these galls on the leaves of this white oak in Green-Wood are the results of yet another Cynipidae gall wasp, Phylloteras poculum. Mine was the third iNaturalist report of this species. I tracked the species down on bugguide.net. Bugguide.net doesn’t have an image of the actual (tiny) wasp. So this…
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Galls of It All
So it seems we still aren’t quite sure how galls are created. Something irritates a plant; the plant responds by creating a unique growth. The hundreds of species of tiny gall wasps are the best known gall-forcers, but other insects (aphids, mites, others) and some microbial forms do it, too. But let’s stick with the…
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Hedgehog Galls
Why, they’re miniature Tribbles! This white oak has been hosting these structures for years now on its leaves. But this is the first time I’ve seen them so fresh. They’ll brown up over the summer.A tiny wasp, Acraspis erinacei, known as the Hedgehog Gall Wasp, creates these in conspiracy with the tree. Essentially the wasp…
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Galls
You may know of my fascination with galls, the structures created by plants in response to insects. In the Botanisk Have in Copenhagen and in the Alnapsparken at Sveriges Lantbruksuniversitet, the Swedish agricultural college, I found these lovely knopper oak galls. They were growing on acorns of Quercus robur, the great oak of Europe, which…
Backyard and Beyond 