Chemical ecology of Bagrada hilaris (Burmeister) (Heteroptera: Pentatomidae): intraspecific and interspecific chemical cues

The chemical ecology of Heteroptera insects is determined by a wide array of chemical signals (semiochemicals) that drive their behavior at intra- and inter-specific level. Intraspecific semiochemicals are called pheromones, interspecific chemicals are named allelochemicals. In the case of stink bugs, sex-pheromones and aggregation pheromone are produced by adult males. Furthermore, phytophagous stink bugs exploit chemical cues emitted from plants to find a suitable food and oviposition source. The semiochemicals involved in this process are named kairomones and are generally formed by specific blend or key odorants emitted from host plant. The chemical ecology of the phytophagous Pentatomid species Bagrada hilaris, or Painted bug, native from Asia and invasive in the Americas is characterized by similarities and differences with the other stink bugs. In particular at intraspecific level is been observed that males volatiles attract females, and chemicals analyses showed that both adults produced a similar pattern of chemicals, with the only quantitative difference related to (E)-2-octenyl acetate, produced in higher amounts from males. However, the possible attractant role of this compound at intraspecific level is still to be assessed. Moreover at interspecific level, although B. hilaris is reported to be highly attracted to brassicas, few studies have attempted to elucidate the chemicals cues exploited in its host location process. In the specific, the chemicals cues exploited from this pest in the location of host plant at seedling stage, the stage more vulnerable and subjected to the attack from B. hilaris have still never been investigated.