Maera is superficially quite similar to the Wall (Lasiommata megera), although there are significant differences on close inspection. Megera is declining alarmingly in the UK but still reasonably common in southern France, although maera sometimes seems commoner, especially at medium and high altitudes. Maera does not occur in the UK. Maera often poses quite obligingly for photographs, although it has a habit of settling in the dark shady areas on walls and rocks, presumably to escape the heat in the middle of the day. The nominate form of maera is easy to differentiate from megera as it is almost uniformly dark brown (not to mention maera usually being appreciably larger). However, the female of the maera southern form adrasta, which is said (in H&R) to be the predominant form in southern France and Iberia, has lighter markings and is more extensively orange, making differentiation from megera slightly more difficult. I have seen adrasta in the Pyrénées, but on balance I believe the maera in Var (as in 9279) are of the nominate form, so I wonder if H&R is right on this point.

Tim Cowles' detailed analysis points up the key differentiators between megera and maera, including the underside where three of the maera ocelli (s2, s3 and s6) are appreciably larger (clear in 15047 and to a lesser extent in 13031), whereas the six megera unh ocelli are of broadly equal size. You don't tend to find invaluable information like this in books.

There is also the Northern Wall Brown (L. petropolitana) which is very similar to the nominate form of maera, which belies its name as it is found in Scandinavia and the Alpes and Pyrénées, but not in between. Petropolitana is slightly smaller and darker and has a clearer, although sometimes not very distinctive, discal line on the uph.

observations

a typical male of the nominate form.

a male of the nominate form.

a female.

a female of the nominate form.

a female of the nominate form, not quite orange enough to suggest the form adrasta.

a male, based on body shape.

a male underside of the nominate form.

a male underside of the nominate form.