Evaluation of Brassicaceae Seedlings as Trap Plants forBagrada HilarisBurmeister in Caper Bush Cultivations

The caper bush,Capparis spinosa(Brassicales: Capparaceae), is intensively grown on Pantelleria Island (Trapani, Sicily, Sicilian channel) where it has been granted protected geographical indication (PGI) by the EU. On this island,Bagrada hilaris, a stink bug native of Asia and Africa, is the major pest of caper crops. Recent studies have shown the attraction ofB. hilaristo volatiles of brassicaceous plants at the seedling stage. The objective of this study was to evaluate three cotyledon-stage seedlings of host plants,Brassica oleraceavar. botrytis (cauliflower),Eruca sativa(rocket) andBrassica carinata(Abyssinian cabbage), as potential trap plants forB. hilaris. The relative preferences of these species were first evaluated in laboratory and field experiments, carried out during summer when the level ofB. hilarisinfestation was the highest. Behavioral bioassays in the laboratory conditions showed that adults ofB. hilarispreferred to orient toward seedlings ofB. oleraceaandE. sativaoverB. carinata. Field experiments confirmed these results. Then seedlings were tested in trap plant trials, by sowing them in artificial pots formed with aluminum trays and placing them in caper fields infested withB. hilaris. Results showed thatE. sativaandB. oleraceadiverted hundreds ofB. hilarisindividuals from the capers to these sources of attraction. Overall, these results suggest thatB. oleraceaandE. sativaseedlings used as lure inside traps or as trap plants may be a useful tool in the management ofB. hilarispopulations.