End of Season Insect Notes

(Not that the season ever really ends, but it sure is reduced over winter…)

I didn't see a single Common Buckeye/Junonia coenia in NYC this year. Only six observers did: these six observations compare with 77 observations in 2022; 52 in 2021; 106 in 2020; 390 in 2019; 16 in 2018; and 34 in 2017. (2019!)
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Why do Bald-faced Hornets/Dolichovespula maculata do so well in the city but Common Aerial Yellowjackets/Dolichovespula arenaria not so much? ID may itself be an issue: Bald-faced are one of the easiest wasps to identify; Common Aerial, being rather Vespula-like, are much harder to parse. But look at these numbers: 1,193 maculata versus 41 arenaria. Only two confirmed arenaria nests have been observed in the city. Once the leaves drop, it’ll look like a maculata nest on every block. This is hyperbole, but they do take well to the city for some reason(s), and not just in the parks.
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I saw my first Asian Mud-dauber/Sceliphron curvatum this year, at the Narrows Botanical Garden in Brooklyn. I also observed what I think is one of their mud nests, in Prospect Park. So there are now a total of 19 observations in NYC (the Bronx, Manhattan, & Brooklyn) by 17 observers. The first was reported in the Bronx in June 2020. As there were no observations in 2021, 2023 was thus the biggest year for sightings so far. It will be interesting to observe the spread—or not. According to Bugguide, they were first noted in North America in 2013 in Quebec.
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Where are Green-Wood’s Organ-pipe Mud-daubers/Trypoxylon politum? There are plenty of old mud nests, but I’ve never seen a live wasp there. And I haven’t seen any nests that look like they were built this year. (I have seen the wasps in past years in Prospect Park, and did see new-looking nests there this year.) Of the 95 observations of this species in NYC, only a hymenopterist’s dozen are of the insects themselves. The rest are of those distinctive nest structures.
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Computer Vision is remarkable, but when it comes to arthropods it still leaves much to be desired. A lot of organisms are going to Research Grade because of the CV and a few serial identifiers, some of whom seem pathologically eager to build up ID stats at the expense of the iNat mission, when species level can only be determined by microscopic examination.
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For an identifier, the iffy observations that flood iNaturalist from reluctant students in classes or bioblitz are pretty disheartening. We’re still getting tours of local zoos from a college-level Wild Flora and Fauna class. Such junk data-dumps rarely mar the arthropods, but this fall did witness a dozen observations of the same Hackberry Emperor/Asterocampa celtis in Brooklyn by bioblitzers. This is a rare species for Brooklyn; these repeats increased the total number of observations of this species in Kings Co. to 33. That’s a jump of a one third, so it gives a quite misleading impression.

Along these lines, it’s depressing to see a series of unclear photos of the same damselfly in somebody’s hand. (Ditto for other insects in a jar.) You’ve gone to all that trouble to capture and bother the animal, but for no real purpose. Even with good photos, the points of damselfly ID—color, eye spots, thorax pattern, abdomen pattern—are not shown because cell-phones just don’t cut it, and the way the creature is pinned against the hand. Holding by the wings also obscures the stigma details, which are key for a few species.
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It’s been ten years since I’ve seen a feral Western Honeybee/Apis mellifera hive/nest in Green-Wood. It was in hollow of a mature oak. I saw it active in 2010 and 2013. (The one other feral hive I’ve seen in there was in a dead tree that was later cut down.) There are 3,596 verifiable honeybee observations in NYC, but the vast majority of these should probably be marked Casual. They’re livestock, unless you have evidence of feral hives.

Posted on October 22, 2023 12:32 PM by matthew_wills