in the laboratory, for egg laying. The adults were allowed to lay eggs for three consecutive days. The larvae hatching from the eggs were reared on garlic mustard, Alliaria petiolata, until pupation under a diapause regime, 20 °C; 12:12 LD (light-to-dark ratio) in 1.5 L plastic jars with five larvae in each jar. Pupae were stored at 1 °C for 8 months. On 30th March 2010, the overwintering pupae were transferred to 22 °C; 22:2 LD until adult eclosion.