20 July 2016
20 July 2016 – Chalky White Moths
Tuesday’s moth trap was sizeable in number as well as species, a few of which caught my attention immediately. Gypsonoma dealbana, is unlike any other ‘bird-dropping moth’ we’ve had so far (e.g. H. pruniana, H. nubiferana) in that it has a more extensive white patch that clothes about two-thirds of the moth. It is further distinguished by the oblong black dot in the center of the white, the orange quarter circle at the apex, and white ‘hairs’ on the head. I thought its name had an ethnic root but it is actually from ‘gupsos’, meaning chalk, and ‘nōmaō’, to distribute, both denoting the broad white fasciae. ‘Dealbo’, whitewash, reiterates this meaning. It is more active in the south of England so ours is a good find. The first sample in VC62 was not recorded until 2000. The caterpillar goes through several stages of feeding, first in a silk tube on the underside of leaves, then buds and catkins, then spun shoots.
This 5mm micro looked like it was in the middle of a yoga routine when we barged in with the camera, trying to tame the lens to focus. The precarious resting position has been achieved by standing on two legs, with its head lowered and abdomen raised. Like other species in the genus, the Argyresthia retinella has an oily, pearly gleam. The ground color is a silvery white, dabbed occasionally with tiny black spots. A shaky longitudinal streak runs from the base to just beyond one-half, ending in a blob. Another diffused dark patch starts from the apex and cuts off at around the tornus. Like the Cherry Bark Tortrix from our last post, this moth also flies in the afternoon sun.
Its name, ‘arguros’ means silver and ‘esthēs’, a dress, both account for the color of the forewing. Rete, a net, describes its netted pattern. On ‘Yorkshire Moths Flying Tonight’ it is classified as ‘scarce and local’, so once again, we are in luck!
Both species are new to Shandy Hall gardens and the total is now 385.
Post: Tung Chau (UPenn)