This is a recently recognised species whose distribution is still poorly understood. The above map is taken largely from Leraut, with minor changes.

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.