A mid-size Pyrgus generally found at low altitudes, Lafranchis giving its altitude range as 0-1300m. It is not as common as other Pyrgus with which it might be confused, such as the Oberthur's Grizzled Skipper (P. armoricanus). Its range in France is limited to the south-east.

It is difficult to identify with confidence from the upperside alone, although a view of the characteristic underside is usually adequate to confirm onopordi. The upperside ground colour is dark brown, sometimes with a diffuse flush and the upf white marks are strong and clear, even in the female. The uph marks are usually diffuse and vary from clearly visible to poorly contrasted, the male more strongly marked than the female as is usual for Pyrgus, although neither sex is as strongly marked as the one species it could be confused with, armoricanus.

The unh defining feature is the so-called "anvil-shaped" (the French books describe this as "en forme d'un enclume") discal mark in s4/5 where the concavity is reasonably even on both sides, making a rather symmetrical shape; however, this is "classic" onopordi but many onopordi have "anvils" that are not entirely symmetrical. Some similar Pyrgus have discal s4/5 marks that are decidedly straight on the internal edge.

The discal s1 mark is a bump seriously leaning internally which has the curious name of the "signe de Blachier", presumable by - or after - Blachier, who was a famous lepidopterist around the early 1900s. This mark is unique among Pyrgus in that it appears that the top half is shifted basally in respect to the bottom half; the degree of this "shifting" can vary considerably but is normally discernible. The unh ground colour is a light yellow-brown and the markings usually have black edging to a greater or lesser degree, creating what the books describe as a marbling effect. The veins are often slightly lighter and prominent.

H&R describes onopordi as bivoltine, two broods being on the wing April-June and again in July-September. I find I encounter it far more frequently in the early Spring, when there is little doubt as to its identification as the only other Pyrgus on the wing then is the Grizzled Skipper (P. malvae). Lafranchis says there are two or three broods and I have found onopordi in Var in April, June and September, strongly suggesting that three broods occur (or can occur) in the far south of France.

observations

I believe this is typical onopordi, more lightly marked as it is a female. The strong dark brown colour is in my experience an indication, plus the yellowish tint, and the early flight period virtually excludes any other Pyrgus it might be confused with.

the ground colour is a very pale, washy, yellow-brown, making the white marks rather indistinct. The anvil unh discal mark in s4/5 is rather flat-edged internally although strongly black-edged externally. The unh s1 discal mark is not a typical "signe de Blachier". It is not a classic onopordi, but clearly cannot be anything else.