Thursday 7 August 2008

Yellow Peril

It's Yellow Underwing time in the moth traps. There are seven species in the genus Noctua that occur in the UK. One, the Lunar Yellow Underwing doesn't occur in Kent but the others are all around at the moment. They're a bit of a problem, not to identify, but they tend to be yobs. They crash round the traps waking everything else up and are generally far too boisterous.

Large Yellow Underwing

The commonest and one of the Largest is the Large Yellow Underwing, it is also very variable in colour. The thing about underwings is in the name, you don't see the yellow until they fly so until then the variability can be confusing.

Large Yellow Underwing

It is a large moth, with a forewing of about 25mm, and they often have a pale leading edge to the wings.

Broad Bordered Yellow Underwing

I only catch a few Broad Bordered Yellow Underwings each night, compared to up to 100 of the previous species. Although the ground colour is variable the basic pattern is always very obvious. They are about the same size as the large Yellow Underwing and can be just as active.

Lesser Yellow Underwing

The Lesser Yellow Underwing is about two-thirds the size of the previous two, and varies in ground colour from pale brown to dark greyish-brown. Not as numerous as it's larger relative, with a peak of about 30 in a night.

Lesser Broad Bordered Yellow Underwing

A much smaller moth, but very fidgety, the Lesser Broad Bordered Yellow Underwing is at is most numerous about now. With more than 100 in a night this wouldn't be a problem were it not for the next species, Lanmaid's Yellow Underwing. It is very similar and although it is nearly always duller and slightly smaller I tend to look at all of them to make sure it's I've got it right.

I described the differences a while ago, but it get more difficult as the normal Lesser Broad Bordered Yellow Underwings get more worn and begin to fade.

Least Yellow Underwing

The last of the yellow underwings is the Least Yellow Underwing. With a forewing only about 15mm long and an entirely different look to the top of the wings it tends to fool a lot of people until the look at the underwing or see it fly. I only see a maximum of dozen or so of these each year.

Tree Lichen Beauty

A week or so ago I caught an unusual (in my limited experience) Tree Lichen Beauty moth, the one I caught today is the type I'm more used to. It shows the T mark that is usually characteristic.

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