2020 December 30

 

    Some frustratingly difficult Operophtera (Winter Moth) puzzles from Jochen Möhr in Metchosin today.   Are they the native O. occidentalis, or the introduced European O. brumata?   Jeremy Tatum writes:   If the moth is rather uniformly grey or brown and unpatterned, I believe it to be O. brumata.   O. occidentalis is usually heavily patterned – but O. brumata can be heavily patterned, too, so that makes things difficult.  However, some well-patterned Operophtera have the middle terminal cell darker than the adjacent cells, and this middle terminal cell is often “grasped” by a dark H in the middle of the forewing.  This creates an impression of a dark streak from the middle of the forewing to the middle of the outer margin, particularly obvious when viewed from a distance.  I believe (though it may need DNA work to be certain) that these are O. occidentalis.   I have labelled them below as best I can, but cannot guarantee!

 

Operophtera brumata (Lep.: Geometridae)  Jochen Möhr

Operophtera brumata (Lep.: Geometridae)  Jochen Möhr

Operophtera brumata (Lep.: Geometridae)  Jochen Möhr

Operophtera sp.  (not sure!)  (Lep.: Geometridae)  Jochen Möhr

Operophtera occidentalis (Lep.: Geometridae)  Jochen Möhr

Operophtera occidentalis (Lep.: Geometridae)  Jochen Möhr

   And if these aren’t difficult enough, how about the next one!   Because it is holding its wings in a more rooflike manner than geometrids usually do, it looked a slightly different shape than a typical winter moth (apparently narrower and more pointy wings), and deceived me into thinking that it was something totally different!  Thanks to Jochen Möhr and Libby Avis for convincing me that it is  Operophtera brumata again.

Operophtera brumata (Lep.: Geometridae)  Jochen Möhr

More puzzles in line for tomorrow!