Figure 1.

Overview of experimental setup, testing preference, and performance of herbivores arriving in different orders and with different times of arrival on Brassica oleracea . (a) Twelve treatments applied to the plants. Treatment capital letters indicate the start of plant induction on day 0: N, no herbivores; A, aphids, Brevicoryne brassicae; C, caterpillars, Plutella xylostella; B, both insects simultaneously arriving on day 0; o, no new herbivore induction initiated on that day. Performance of the two inducing herbivores is measured after day 5. Mamestra brassicae preference and performance on those induced plants is subsequently tested in a 24‐h choice test, and after a 48‐h growth bioassay, respectively. Only a subset of plants are used for the M. brassicae choice test, using only comparisons among treatments that differed most in timing of arrival between inducers (N, A, C, B, CooA, AooC), omitting treatments with 1‐d interval between arrival of the two herbivores and their controls (AC, CA, oC, oA). (b) The infestation procedure. The three youngest unfolded leaves were infested with five aphids and/or two caterpillars according to the treatments. (c) Sampling of leaf disks. After the induction period, leaf disks were randomly sampled from each infested leaf. For the two‐choice experiment (left), six leaf disks were sampled; for the performance experiment (right), two leaf disks were sampled per induced leaf.