Boeticus is a migratory species and seems to be quite widespread, although before 2012 I had never seen more than one specimen in any given place. It could be confused with the Lang's Short-tailed Blue (Leptotes pirithous) on the basis of the underside patterning, but boeticus is generally much larger and more triangular, and the continuous post-discal unh white band is definitive. The marginal markings in s1 and s2 (more so in s2) are beautifully edged in silver scales and internally edged in orange.

It can use a variety of different plants of the Fabaceae (Pea) genus as larval hostplants, possibly the most frequent being Bladder Senna (Colutea arborescens) but the ones I saw in 2012 were using Broad-leaved Everlasting Pea (Lathyrus latifolius) (31567)

It seemed to be more numerous in 2009, turning up in several localities, and this impression was reinforced by other observers. Maybe 2009, the year of the Painted Lady (Vanessa cardui) migration, was a good year for migrants generally. I subsequently saw only one in 2010 and none in 2011, but in September 2012 I saw several in three different coastal locations. This seems to have been the pattern in other locations, so clearly 2012 was a good year for boeticus.

In 2015 and subsequent years, I encountered this species in numerous locations, so perhaps it is becoming more common, maybe just spreading northward.

observations

I am assuming that this is a male, despite my doubts about the quite strongly brown colouring, and to some extent the wing shape, both of which suggest female. Maybe it is a female just taking moisture, as other species - clearly females - were doing at this same location.