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A couple of micros for id/confirmation please

Posted: Tue Nov 10, 2020 5:24 pm
by Tim_Ward
30 moths of 17 species in the trap last night, including 5 micros. I'd welcome help with a couple.....
First is a Caloptilia.....I wondered if it might be betulicola?
Second is a Crambid.....I wondered if it might be a Rusty-dot Pearl (Udea ferrugalis)
Both would be new for my garden, so here's hoping.........
Best wishes,
Tim

Re: A couple of micros for id/confirmation please

Posted: Wed Nov 11, 2020 10:47 am
by stevehind
Hi Tim
John Rayner posted one of these recently which we thought was probably Caloptilia elongella. Caloptilia betulicola tends to have a white trochanter (at the top of the hind leg), whereas on the similar C. elongella the trochanter tends to be the same colour as the wings, although not sure how conclusive this feature is. The former feeds on birch whereas the latter on alder, which may help if one of these is absent in your area. Probably best to dissect it to be sure.
Agree Rusty-dot Pearl Udea ferrugalis
Regards
Steve

Re: A couple of micros for id/confirmation please

Posted: Wed Nov 11, 2020 6:18 pm
by Tim_Ward
Thanks Steve. I will dissect the Caloptilia as suggested.
Best wishes,
Tim

Re: A couple of micros for id/confirmation please

Posted: Thu Nov 12, 2020 4:56 pm
by Tim_Ward
Hi Steve,
Based on my dissection, I believe it is Caloptilia betulicola, which fits with the fact that I have Birch at the end of the garden and no Alder anywhere nearby. A rather fiddly dissection but I think that the genitalia indicate betulicola. Do you agree? (see photos)
Tim

Re: A couple of micros for id/confirmation please

Posted: Fri Nov 13, 2020 10:30 am
by stevehind
Hi Tim
I was afraid you might ask me for an opinion on this one as I often struggle separating the males from those of Caloptilia elongella.

I've found the comments below which may help you, otherwise I suggest asking on the Facebook Dissection Group.

Regards
Steve

betulicola:
Aedeagus tip: aedeagus tip consists of two sclerotized arms, one straight, the other with a bend, but straightening out again at the tip. In this species the straight extension is usually (3/4) forked at the tip; the other extension is usually unforked (1/4)
The smaller cornuti within the aedeagus are longer and larger than in elongella; about, or almost as long as the width of the aedeagus; number of cornuti: 6-10.
The bunch of larger cornuti in the vesica: are longer than in elongella; number of cornuti: 6-8

elongella:
Aedeagus tip: neither apical arm obviously forked (one specimen has a very small apical bifurcation)
The smaller cornuti within the aedeagus smaller and shorter; ⅓ to ½ width of aedeagus; number of cornuti: 9-11
Note: it is difficult to see these in the Dissection Group image.
Larger cornuti in vesica: shorter, number of cornuti: 10-14

Re: A couple of micros for id/confirmation please

Posted: Fri Nov 13, 2020 4:36 pm
by Tim_Ward
Thanks Steve,
The additional criteria you sent me are very useful. Based on these, I am now convinced that this is betulicola and will record it as such.
Many thanks,
Tim