In Spain, the queens are reported to emerge very late in the year (July) to take advantage of the flowering period of its forage species - Aconitum spp. (Ranunculaceae). The species flies from July to September. (Ornosa & Ortiz-Sánchez, 2004).
Westrich (1989) states that the queens emerge in late May, and the young queens and males are produced at the end of August.