*2.1. Insects*

Last-instar larvae of *C. perspectalis* were collected from unsprayed *Buxus sempervirens* trees located in a private garden in Staré Hodˇejovice (South Bohemia, Czech Republic, 49◦ N) and maintained in net cages at a room temperature with 16L:8D photoperiod for a few days before they were used in bioassays. Young twigs of untreated box trees collected in the vicinity of the Biology Centre, Cesk ˇ é Budˇejovice were provided as food and replaced with fresh ones when needed.
