Floral volatiles allomones

Larvae of the poisonous European blister beetle Meloe proscarabaeus (Coleoptera, Tenebrionoidea, Meloidae) parasitize multiple solitary bee species. These larvae (called triangula) lure bees by emitting a bouquet of volatile compounds that closely resembles floral scent. Chemical analyses reveal a complex blend of monoterpenoids derived from (S)-linalool, a ubiquitous floral volatile. These compounds function as floral-scent mimics, eliciting attraction in bees and acting as allomones (i.e., interspecific chemical signals that benefit the emitter while disadvantaging the receiver). The P450 enzymes CYP345BZ1 and CYP347BT1 (both CYP3 clan) are the first steps in hydroxylation and epoxidation of (S)-linalool as shown in the figures below from the remarkable paper “the floral illusion” of Alam et al., 2026.