Intra- and inter-specific cues for the management of Bagrada hilarisin caper bush cultivations
Abstract: This paper summarizes the advances in the last ten years about the semiochemicals involved in intra-specific and inter-specific communication of Bagrada hilaris, an invasive stink bug damaging the caper bush on the island Pantelleria, Italy. The identification of the chemical cues regulating the behavior of this pest at intra-specific and inter-specific level can give the opportunity for new strategies for its management. The intra-specific communication studies on this species showed that (E)-2-octenyl acetate is a major volatile compound emitted by adults. Laboratory bioassays showed that this compound elicit attraction toward B. hilaris females and nymphs. A field experiment using double-funnel traps confirmed this response, however, the low number of captures recorded discourage the use of such lure for monitoring purposes. Inter-specific semiochemicals play an important role in the attraction of B. hilaris toward its favourite hosts: seedlings of brassica plants at cotyledon-stage. In particular, the attraction seems mainly mediated by brassicadiene an uncommon diterpene, emitted by the most susceptible species as Brassica oleracea var botrytis. Field experiments using seedlings of brassica plants as source of attraction showed to have potential as a trap crop for the painted bug to protect caper fields.