Fig. 2

Experimental design of the reciprocal transplant experiment and sequencing. a. Diapausing larvae were collected from maize stands for ECB and from mugwort stands for ABB and reared in the laboratory until the adult stage. France map was downloaded from the ‘map’ package from the R software. b. Male and female adults (about 10 in total) were placed in breeding cages and allowed to mate freely. Their progeny was reared to pupation on an artificial diet. After emergence, single mating pairs were established. The progeny of mating pairs that laid more than 10 egg masses, was split into equivalent batches before plant infestations in the various experimental set-ups and replicates. c. Mature egg masses were placed on the bottom side of leaves, in insect-proof cages (four replicates of each “moth species x plant” set-up) in outdoor conditions in the South of France, until the fourth instar (L4) was obtained. The larvae were then sampled, weighed, flash-frozen in liquid nitrogen, and stored at − 80 °C until RNA extraction. d. For three replicates of each set-up, total RNA was extracted and equimolar pools of RNA from about 20 larvae were sequenced on a HiSeq2000 (Illumina, 2 × 100 bp)