Clouded Yellow

[Polly]

Hi All
I am assuming that the attached photograph is of a helice Clouded Yellow. I took it yesterday after she had been egg-laying at Ditchling Beacon, East Sussex.

Can anyone tell me how you differentiate between helice, Berger's and Pale please???

[David M]

Can anyone tell me how you differentiate between helice, Berger's and Pale please???

With great difficulty!!

The fact that it was in the UK makes it almost certainly helice, but both the other species have reached our shores in small numbers in the past.

[Padfield]

You can't really see enough of the forewing border here to rule out pale clouded yellow but you will have seen enough in flight as you watched it flitting around looking for places to lay eggs. It's probably too late now if you didn't consciously notice, but the dark border tapers off towards the trailing edge (behind the pale spots, or leaving at least one 'open') in pale clouded and Berger's but stays strong and parallel in clouded yellow (enclosing the pale spots). In the field, it is nearly always from seeing the butterfly in flight that you distinguish between clouded yellow and the other two. More often than not, helice females have a cream or pale yellow flush under the forewing (which yours doesn't) but this is not always present or obvious.

Distinguishing between Berger's and pale clouded can be very difficult, though some fit clearly into one or the other bracket from the wing shape. However, an egg-laying female can give the game away! Berger's lays on horseshoe vetch and crown vetch while pale clouded prefers clover (but also takes a range of other plants). What plant was your butterfly interested in/laying on?

Guy

[Polly]

Thanks for your reply Padfield.

Unfortunately I didn't get good enough views of her upper wings. She was flying fast!

I am attaching the only photo I got of her laying. Does it help at all???

[Padfield]

Interesting! That looks like yarrow, and I've never heard of any of them laying on yarrow. But from the slightly more you can see of the butterfly I think she is clouded yellow.

Guy

[Polly]

Thanks very much!