This is a
recently recognised species whose distribution is still poorly
understood. The above map is taken largely from Leraut, with minor
My experience of Austaut's blue is principally from Málaga in spring
and the Córdoba region in July. Spring males are very similar to common
blues, though the dark marginal line is on average wider and a little
more diffuse, on the forewing in particular. It seems to me the leading
edge of the forewing is less obviously shining than in common blue
(true also, in my experience, for summer brood males), though that is
something I will have to confirm. There are commonly black spots around
the outer margin of the hindwing - something quite rare in common blue.
The summer males I saw quite commonly around Córdoba were all much
smaller than a typical common blue, though it should be said this was a
particularly hot year and the vegetation was completely dried up. They
were also quite a different colour - paler and tinged with violet. The
hindwings sported dark spots inside the outer margin, as in the spring
brood. The borders of the forewings were generally very broad and the
whole impression was of a very different butterfly - nothing like a
normal common blue. The few spring females I have seen have been very
blue. I cannot recall seeing summer females.
The biology is presumably similar to that of common blue but evidence
for this is scant. Foodplants are various members of the Fabaceae and the
butterfly hibernates as a caterpillar.