by stevehind on Fri Nov 13, 2020 9:30 am
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