15 June 2017

15 June 2017 – Rare Moth on Speedwell

(Cauchas fibulella) and Bird’s Eye flower

Walking through the garden, a micro moth was spotted on a leaf near a clump of Germander speedwell (Veronica chamaedrys). It was unfamiliar and quite striking. Naturally, we got the camera and started taking pictures. After uploading the images all four of us huddled around my computer comparing the photographs with ones found online and in the micromoths guide book. We came to a democratic consensus that the moth was either a Cauchas fibulella or an Adela fibulella. After sending the photographs to Charlie Fletcher, he confirmed that the moth was both Cauchas fibulella and Adela fibulella as it had had a change of its scientific name.

Adela means ‘unseen’ and it refers to the larvae concealing itself in a portable case; fibulella is defined as ‘a clasp’ which describes the appearance of the moth and how the two dots, one on each forewing, come together when at rest. Cauchas fibulella is a rare species in North Yorkshire and this is only the third to be recorded.

The larvae feed on germander speedwell of which there is plenty in the garden. They first feed on the seeds but later build a portable case and feed on the leaves closer to the ground.

If you have any Bird’s Eye in your garden (it’s a good luck charm for travellers so there should be), find a sunny ten minutes and go out and see if you can spot the little moth – perhaps they aren’t as rare as they seem to be.  When they fly it is quite a whirring of wings and they are easy to follow.

(Cnephasia sp.)

Another moth caught in the trap turned out to be difficult to identify. At first, we believed it looked like an Isotrias rectifasciana but our moth was too big.  It seems it is likely to be one of the Cnephasia species and they are very difficult to tell apart. Another Cnephasia sp. was recorded about three years ago so we can’t count this as a new species – but our Chaucas fibulella (or Little Longhorn) has already made the total 408 different species.

Post : Walter Chen [UPenn intern]