A Spot of Moth Intrigue

I can never think about moths without thinking of Jethro Tull – track 4 on Heavy Horses: Moths, which has a line including, “… the first moths of summer…”. I’ve put it on now. 🙂

IMG_1652_(Svenssons)_Copper_UnderwingOne of these characters certainly was from summer – July in southern France, though it does occur in England. Since I am self-confessed moth numbskull, I resorted to iSpot for identification help. Little did I suspect the interesting debate that would ensue. First of all, here is my subject. I performed my usual rudimentary attempt at identification and came up with Copper Underwing as a suspicion. What I didn’t spot right beside Copper Underwing, was Svensson’s Copper Underwing. The two are, it seems, v. difficult to distinguish in the field and, I’d suggest, pretty much impossible from a simple photograph. Furthermore, the reliability of some of the so-called distinguishing features, is disputed. The problem is, perhaps, best illustrated by giving a flavour of the experts’ comments:

A very complex debate, with some stating no characteristics distinguish these reliably, only genital. If you are going to try and come up with an ID, … it’s necessary to look at ALL the published characteristics to come to a decision taking everything into account, including fore-wing, hind-wing, palps, etc…

Examination of the underside of the hind-wing on a fresh specimen is I think currently regarded as the only valid way to separate them. If it is not fresh then dissection may be required.. [Ed: ❗ ]

I believe some say that even hind-wing (both upper and underside) are invalid ways of separation; however I haven’t done any research or seen any sort of proof.

I think the situation is if it has the features of Svensson’s (copper extending up the underside of the hindwing) it is one. If it has the features of Copper Underwing, then dissection is probably necessary. . [Ed: ❗ ❗ ]

There are a few species (e.g. November moths) where you can extrude the relevant features (on a male at least) on an anesthetized specimen and do it with a hand lens.

You get the idea – certainty appears to require the killing of the hapless creature or, at the very least, anaesthetizing it to drag its genitalia about, I presume with tweezers or the like. No thanks! I’d much rather see it in all its incognito glory. poor old Copper Underwings! I will be satisfied to refer to this as a [Svensson’s] Copper Underwing. I’m also happy to think that I got the right [aggregate] identification.

IMG_0022_Spring_Usher_maybe_Spring_UsherSpecimen number two is more recent and decidedly nothing to do with summer. Last week it flew into our kitchen and took a shine to the shiny white door of our dishwasher. Regrettably it wasn’t any more adept at emptying it than are we. Once again, I was fighting with Townsend, Waring and Lewington to come up with a likely identification and, once again, here’s the subject of my intrigue. After a couple of “probably not”s, I thought I had it: a Spring Usher but there were words in the book that were clearly not designed to inspire confidence:

… Variable, but with wavy outer cross-line and curved inner one, sometimes forming edges of pale central band. May also be dark brown and almost or entirely uniform. …

This much variability is a real pain for an amateur moth numbskull; I needed iSpot again to help. It seems I was right, though. Another all-too-rare moth feather in my cap. 😀 [The female, BTW, is flightless – not a wing in sight.]

Now, Spring Usher, I’m good and ready for you to do your work.

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