Friday, 26 August 2011

A Thorny problem

As Autumn is now upon us the mix of moths takes on a distinctly different character. One of the joys at this time of year is the group of "thorns". Split into two genera, Ennomos and Selenia, they are predominately yellow moths. Those in the genus Ennomos are Autumn moths that tend to rest with their wings held at around 45 deg.

They can present some identification problems but the Large Thorn that was in my trap last night was distinctive. It is larger than the others and there is distinctive mottling both on the upper and lower surfaces of the wings.

Although they are in the family Geometridae, where many of the moths have quite delicate bodies, the Thorns are quite chunky and are probably quite a delicacy for a Great Tit or Blackbird.

One of the striking things on this male is the fantastic feathered antennae, which distinguish it from the female. Hopefully I'll be seeing some of the others in the next few weeks. Dusky Thorns are already around but both August and September Thorns, somewhat misleadingly named, and my favourite, the Canary Shouldered Thorn, have yet to put in an appearance this year. The other group in the genus Selenia rest much more like butterflies with wings closed. The Early Thorn has, as is implied by the name, an early generation and a second one that's around now. The Lunar Thorn is another early moth, although I've not caught them then, that has a small late second generation in August that I've only caught twice. The last of this group is the Purple Thorn, that can have three generations, I've only caught two here, both in July, which should be the middle one.

1 comment:

Marc Heath said...

That 3rd shot is lovely, not a great moth enthusiast but that a nice shot.