My normal practice is that I photograph all moths of which I'm uncertain after visual examination (with hand-lens if necessary) or for which a photo would be a good idea to support the record, and I also photograph the first appearance of a species each season and anything else that's unusual. Moths in the first category are recorded in my notebook with "TBC" or "?" after the provisional name (if I have even got that far). This helps me to remember what I'm supposed to keep until it's checked. I don't normally release any moths with uncertain ID until I've checked the photo and come to a definite confusion: many still without a positive ID end up on this blog or in the freezer.
This approach assumes that a confident ID after visual inspection is a correct ID. That's what went wrong with one of the moths that I caught on 17th October. I had got tied up in an urgent project from 18th onwards, so I fell behind on several things, one of which was going through the photos. As the only identification of which I was uncertain was a hoverfly, I had released the moths I had photographed: all of these were meant to be "first of the season", including Pine Carpet, Acleris rhombana, Large Wainscot, Yellow-line Quaker and a Caloptilia stigmatella.
In the end, I didn't get around to going through the photographs until this evening. Imagine my surprise when the photo of the "Caloptilia stigmatella" came up on the screen and it was plainly wrong. Worse, I had somehow been confident in this erroneous ID. So instead of labelling it and moving straight on to the next photo, I needed to think again.
 |
| Caloptilia sp. Newton Longville, 17th October 2022 |
So which Caloptilia species was it? Having been completely wrong with my visual ID, now with the photo I didn't recognise what species it was. After considerable research, it now appears to me that it could be either C. hemidactylella or C. honoratella; C. falconipennella is also a possibility. Any of these would be a notable find and all need the genitalia to be done, but the moth is somewhere in the garden celebrating its liberty and toasting my incompetence. As some kind of consolation, perhaps someone could at least confirm that I'm now on the right track (albeit a track that is going to lead nowhere in the absence of anything to dissect), or tell me that I've gone wrong again and it's a more common species.
There is no alder nearby, and the nearest Sycamore of which I'm aware is a couple of hundred metres away, but I do have Field Maple in the garden.
Tim Arnold
Newton Longville, Bucks
Hello Tim,
ReplyDeleteWhat a shame, but you're not the first to have been in that situation and I'm sure you won't be the last (not that that's any consolation!). The recently-established Acer-feeding Caloptilia honoratella does seem likely to me but it would definitely have needed dissection to confirm the species. Unless there have been any others this year, I'm only aware of one record to date from our area and that was in Bucks (High Wycombe in August 2021). It seems to be moving in from the south and east because Beds, Herts, Middx & Surrey have all had records over the last couple of years.
By the way, don't dismiss Alder-feeding species simply because you haven't seen any of the food-plant locally - it may be there in unexpected places! Alder isn't a feature of the Aylesbury Vale landscape but that hasn't stopped so-called ecologists from including it in the mix of species planted over the years on old land-fill sites or (as is currently happening) on mitigation projects for HS2 and East-West Rail. An Alder which I planted in our garden, now about ten years old, has since last year produced Caloptilia falconipennella which must have found its way here from somewhere reasonably close by.
I did record a couple of C. honoratella in Sibford back in July this year. Identified by Peter Hall. If they are coming from the south-east they could be anywhere in the region as I am about as far north-west as one can be and still be included in Upper Thames.
DeleteSorry, I'd overlooked your post about these back at the beginning of September, Andy! Definitely good news and means we should all be looking out for this species.
DeleteHello Dave. We learn by making mistakes (well, I do!), so let's hope that I'll take a closer look next time. I still can't figure out how I mis-identified it the first time around - my error leapt out at me as soon as the photo came up on the computer.
ReplyDeleteAs you mentioned East-West Rail, I did leave my contact details with one of the EWR ecology team earlier this week as I'm hoping to get access to one of the "compensation areas" about 2½ km to the west of here, once they've finished with it.