22 June 2022
20 June 2022 – Headstand Moth
If you don’t look closely you might well miss the tiny Argyresthia spinosella as it is smaller than the fingernail on my thumb – about 4mm. It is also quite difficult to identify. It is similar to a few others in the Argyresthia family, namely A. conjugella (the Apple Fruit Moth) and A. semifusca. The main difference is size – as these two are larger – and colour. Spinosella is a more orange-brown colour near the top of the thorax at the base of the wing, whereas the other species are more brown-purple. From the photograph above the moth looks fairly plain but I can assure you it is a pretty one.
The posture is clearly seen and at rest it appears to be perfecting its technique of headstanding. Most of the Argyresthia family seem to adopt this declining position. Perhaps this enables them to shine a little as ‘Arguros’ (silver) and ‘esthes’ (dress) define this genus as they are named after the metallic glow on the forewings. Quite a fitting name, I must say. As for spinosella the reference is the food plant Prunus spinosa – blackthorn. It feeds on plums and flowering shoots as well.
This moth can be seen from May to July and is attracted to light – as this one was. We nearly missed recording it but it is now moth species 453.
Mackenzie McKillip UPenn intern