Apparently a bivoltine species but there is a suggestion that it may be univoltine, with an altiduninally defined flight period. The spring generation flying in February and March, and the second flying from May to July (Fellendorf et al, 1999).
Kratochwil & Scheuchl (2013) suggest another explanation could be that two different flight times in lower and higher altitudes exist. It is remarkable that in June, July and August (with minor exceptions) A. wollastoni is active only at higher altitudes. At higher altitudes (from 1000-1570 m a.s.l.) the activity starts in May.