Moth Monday: Silver Y

Where the name Silver Y (Autographa gamma) comes from is quite clear: the distinctive y mark on its wings. There are a couple of other moths with greek letters on their wings, hence the scientific name Autographa ( = self-written). It is a migratory moth, which migrates from south (in Europe the Mediterranean sea area) to north (as far as Scandinavia & UK) during spring and returns to the south in autumn. This way, they profit from optimal weather conditions. Not too hot and not too cold.

Migrating requires quite some skills. The moth needs to sense that the timing is right, it needs to know the direction it is going and it needs to fly over long distances. To do this, the moth has an internal compass and it adopts several flight behaviours. These behaviours include: (I) selection of seasonally favorable tailwinds; (II) flying at the altitude of the fastest winds; (III) adopting flight headings that partially counteract crosswind drift; and (IV) seasonal reversal of preferred directions between spring and fall. By doing this, they could reach speeds up to 90 km/h. Pretty cool for an often overlooked moth!

Silver Y

How many moths migrate or are seen depends on various factors. Some years, weather conditions are bad and thus not many moths reach the stage of migration. Other years, they fly much more north or stay closer to the south. They often visit gardens for resting, sipping nectar, mating and laying eggs. The number of moths in my garden fluctuate. Some years, I see them quite regularly and other years, like this year, I don’t see them at all. The pictures of the Silver Y in my garden are from 2015.

This moth is one of my favorites to see. The Y is a beautiful, conspicuous marking, making it easy to determine. On plants, it blends in quite well. And the longer I look at the markings in the last two pictures, the more it looks like a face. Since this moth is active both day and night, perhaps the markings form a good combination of camouflage and deterrent.

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