Flora volatile profiles of plants visited by Vespa velutina: a preliminary assessment in the interaction of plant-insect

Plants function within complex ecological communities, relying on chemical signals to mediate interactions with other organisms. The foraging behaviour of insects, such as the invasive hornet Vespa velutina nigrithorax, introduced into northwestern Spain over a decade ago, may be influenced by floral volatiles. This hornet detects plant secondary metabolites, including semiochemicals, which aid in locating nectar, carbohydrates, prey, mating sites, and other resources. Understanding the volatile organic compounds (VOCs) emitted by plants visited by V. velutina may help to develop targeted control strategies. The aim of this study was to identify and analyse the volatile compounds emitted by 18 plant species frequented by V. velutina nigrithorax in the province of Ourense, northwest Spain. Solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used in this study. A total of 110 VOCs were identified, of which 21 compounds were abundant in the samples, with terpenes being the most abundant. Furthermore, a PLS-DA analysis selected 33 volatile compounds with variable importance scores (VIPs) greater than 1, in particular methylanthranilate with a value of 1.81. Eleven of these compounds were found to be abundant in the analysed samples, including (Z)-β-ocimene; 1-octen-3-ol; 3-hexen-1-ol, acetate, (Z)-; 3-octanone; eugenol; linalool; methyl salicylate; o-cymene; α-farnesene; α-terpineol and β-farnesene. The selection of these compounds provides valuable insights into plant-insect interactions, highlighting their diverse roles as plant volatiles in mediating insect behaviour and underlining their potential as targets for environmentally friendly pest management strategies.