lasiommata megera/ lasiommata maera

Wall (Lasiommata megera) and Large Wall (Lasiommata maera)

2009 photos highlighted in yellow. Click on any photo to go to an enlarged picture, or simply scroll down the page.


7900_male_Isere_5Jul07 - maera	8044_male_Isere_6Jul07 - maera	12324_male_Isere_9Jul08 - maera

13031_male_Valais, Switzerland_16Jul08 - maera	9279_female_Var_28Aug07 - maera	15047_male_Var_09May09 - maera

18612_female_Isere_14Jul09 - maera	6678_male_Alpes Maritimes_8Jun07 - megera	7144_female_Var_18Jun07 - megera

7077_female_Var_16Jun07 - megera	10376_male_Alpes Maritimes_9May08 - megera	19142_male_Gard_28Aug09 - megera

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. Megera emerges very early in the season and again in October when it seems to be quite common, in places very common, in Var. 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 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 more difficult. I have seen adrasta in the Pyrenees, 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.

The illustrations of megera in T&L show the female to be very similar to the male, with heavier dark brown bands breaking up the orange as in 10376. This originally led me to believe that 7077 and 7144 were maera of the form adrasta as they were much closer to the T&L illustrations of adrasta than to the female megera.

On checking H&R and the Lafranchis ID book, the illustrations of female megera there are much closer to 7077 and 7144, so I am left to consider that the T&L illustration is potentially quite misleading. My thanks to Tim Cowles whose detailed analysis points up the key differentiators, 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 (as in 6678). You don't tend to find invaluable information like this in books. For simplicity and comparison, I decided to put megera and maera on the same page.

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 Alps and Pyrenees, but not in between. Petropolitana is slightly smaller and darker and has a clearer, although sometimes not very distinctive, discal line on the uph.

7900: a typical male maera of the nominate form. Altitude 1450m.

8044: a male maera of the nominate form. Altitude 1500m.

12324: a male maera underside of the nominate form. Altitude 1470m.

13031: a male maera underside of the nominate form. Altitude 1700m.

9279: a female maera of the nominate form, not quite orange enough to suggest the form adrasta. Altitude 1500m.

15047: a male maera, based on body shape. Altitude 450m.

18612: a female maera of the nominate form. Altitude 1230m.

6678: a male megera: the underside carries several suggestions of maera, notably the number of rings in each ocellus, the general light colouring, and the large unf ocellus, but the consistency of the size of the unh ocelli is a sure pointer to megera, as noted above. Altitude 330m.

7144: a female megera, quite extensively marked orange, which, in many respects, looks remarkably like the T&L illustration of the female maera of the southern form adrasta. However, the orange in the uph post-discal region is a pointer toward megera. Altitude 780m.

7077: a female megera. It is exceptionally orange and looks nothing like the illustration in T&L. Altitude 220m.

10376: a typical male megera. A difficult butterfly to approach and photograph, I find. Altitude 1000m.

19142: a male megera, I think, even though it has been suggested that the absence of an orange band in the uph post-discal area indicates NOT megera (and therefore maera) - this is also stated by Lafranchis as a key indicator of megera. However, the upf is so clearly megera that I feel on balance it would be more likely that the uph orange band would be missing from megera rather than maera having the classic megera upf markings. Comments invited. Altitude 580m.

7900_male_Isere_5Jul07 - maera