Insect material
Pieris brassicae L. (Lepidoptera: Pieridae) butterflies
were obtained from a rearing of the Laboratory of Entomology, Wageningen
University. Insects were kept in a greenhouse under standardized
conditions (21 ± 4° C, RH: 60 – 80 %, L16: D8). Larvae were reared on
Brussel sprout (Brassica oleracea var. gemmifera ) cv.
Cyrus, while the adults were fed with a 10 % honey solution and allowed
to oviposit on clean plants of the same genotype.