I am struggling to decided which skipper

[Nigel]

I am struggling to decided which Skipper I photographed today, and I know you experts will be able to help PLEASE.

Many Thanks in anticipation

Nigel
http://www.nigelspencer.co.uk

[Denise]

I'll stick my neck out and say that I think it might be a female Small Skipper.
I can't see a sex brand (which would be a good indicator) but the underside tips of the antenna appear to be brown as opposed to black of an Essex.
I'm sure someone will speak up if I'm wronger.

Denise

[Vince Massimo]

Oooo tricky!

It's a female but can't see the undersides of the antennae very clearly. However I have developed a technique of looking at the length and shape of the abdomen which seems to work quite well. I have observed the the abdomen of the female Essex Skipper tends to be longer than that of the Small Skipper such that it usually projects beyond the back of the rear wing. It also seems to be more pinched and pointy at the end. Based on what I can see on the photo, I would suggest that this is probably a female Small Skipper which has the shorter and more rounded abdomen.

I am really sticking my neck out on this one, but it's fun to test theories like this and I await the views of the proper experts with interest

Cheers,

Vince.

[Vince Massimo]

Hi all,

I am renewing this topic to see if any of our experts can provide any further insights on this question. I suggested an identification based upon a theory I have developed and it would be interesting if someone like Guy has any suggestions based upon other identification indicaters such as colour or other markings.

Cheers,

Vince

[Padfield]

Interesting! I missed this post in the summer. I've never seen a criterion based on abdomen length and will look carefully to see if it holds good!

Obviously, the male sex brand is the best indicator, if you have a male. The antennae are a good second best, but they can be misleading. Small skippers when fresh have a noticeable reddy-buff patch under the tip, but this wears off with age. Essex lacks this patch of colour but the actual extent of black under the tip is very variable - it may be just at the tip. Your butterfly has enough for Essex and that's what it most looks like to me.


(small skipper)

There are at least two other indicators, neither being truly decisive. The first is the extent and neatness of the dark margins, which tend to extend in along the veins more in Essex, giving it a 'burnt' impression. In a typical small skipper the margin is neater, better defined, and comes in along the veins less. The problem is, although this is quite strong statistically, you can get small skippers with quite extensive dark markings around the edges and along the veins. Your butterfly most resembles Essex skipper on this ground.

The second is the contrast between the greyish green colour near the apex of the underside forewing and the orange of the underside forewing. This contrast is much more marked in small skipper than Essex. It is not really possible to see which yours is on this ground. Thanks to Tim Cowles for pointing out this criterion to me.

Lastly, am I right in thinking that's cocksfoot (Dactylis glomerulata) it's sitting on? This is a quite typical foodplant for Essex skipper but much less normal for small, which feeds mainly on Yorkshire fog (Holcus lanatus). It may be quite coincidental that it happened to be on this species when you photographed it, but it's just another little detail.

SO, my overall impression is Essex, but I'm quite prepared to be told I'm wrong. This happens quite a lot!

Guy

[Mikhail]

I agree with Guy. There is another detail of the antennae, seldom mentioned in the literature. The Small Skipper antennae are slightly hooked at the tip: those of the Essex Skipper are not. These characters are very well shown in the enlarged illustrations of the antennae of both species in Thomas and Lewington.

Misha

[Vince Massimo]

Thanks Guy and Misha. Very interesting and helpful comments as always.

Cheers,

Vince