The grizzled skipper: in addition to the pyrgus undersides being much better for ID purposes, the uppersides of fresh specimens can give a good clue – large grizzled (
P. alveus) is (if I understand it correctly) generally dark grey-brown and olive (
P. serratulae) is a deep dark brown, but it’s hard to draw any conclusions if the specimen is very worn. It also highlights that ID is not too difficult in the UK as most species are not subject to local or altitude variation, but in Europe there are so many subspecies and local forms that you would often think they can’t be the same butterfly. This is why experience and local knowledge are vital, so Guy’s ID of
serratulae is the most informed you’ll get. I have seen male
serratulae that had very small white forewing marks, almost pinpoints, but these marks are so variable.
The fritillary: a deeper look:
1) the forewing marginal black mark in space 2, being more prominent than those around it, suggests heath fritillary (
mellicta athalia)
2) the forewing crescent-shaped marginal lunules suggest
athalia
3) the white marks making up the underside white discal band seemed flatter externally, possibly suggest
athalia whereas false heath fritillary (
melitaea diamina) are more rounded
4) the underside yellow marginal band, contrasting with the white bands either side strongly suggests not
athalia and points strongly to
diamina
5) the forewing yellow marginal band is very even and yellow which strongly suggests
diamina –
athalia is usually wavy internally
6) the darker postdiscal hindwing band between the white discal and submarginal bands usually has dark marks or spots within each segment in
diamina, which this does not (photo of
diamina attached), and the circular black edging to these segments seems heavy and slightly fuzzy which suggest not
athalia although I have seen
athalia looking like this. However, the
athalia segments are usually red-filled or have clear round red spots which this doesn’t.
Conclusion: the yellow marginal bands are probably the characteristic least likely to vary and most indicative of
diamina, or at least, preclude
athalia, so I’d go for
diamina. As Guy notes, if you had seen the upperside, you would have no doubt as the darker marks preponderate to the extent that sometimes there’s very little orange visible.
![Image](http://upload5.postimage.org/178430/melitaea_diamina_2103_800.jpg)