Interchangeability of floral volatiles in ternary lure combinations for catching three cetoniin chafer species (Coleoptera, Scarabaeidae)

Abstract

In behavioural field experiments, we aimed to study the interchangeability of molecular structures, which only differ by single hydrogen, hydroxyl or methyl group from components of a known attractant blend of the flower damaging Epicometis hirta (Coleoptera, Scarabaeidae), and two other cetoniin occasional pests Cetonia aurata aurata and Potosia cuprea, typical to the fauna of Central and Southern Europe. Rac. 1‐phenethyl alcohol or methyl eugenol (of the known attractant blend of rac. 1‐phenethyl alcohol, (E)‐anethol and methyl eugenol) were replaced with structurally similar floral compounds widespread among plant families in general. All baited treatments caught significantly more of the three species compared with the unbaited control. The ternary blend containing 2‐phenethyl alcohol caught numerically the most of the three species and gave a significant increase compared with the basic blend with rac. 1‐phenethyl alcohol for C. a. aurata and E. hirta. Benzyl alcohol performed similarly well to 2‐phenethyl alcohol in catching C. a. aurata and P. cuprea, and it was superior to the blend with phenylacetaldehyde. On the contrary, for E. hirta, the treatment containing phenylacetaldehyde was better than the combination with benzyl alcohol, resulting in a similar effect to the blend with 2‐phenethyl alcohol. In another experiment, the known ternary blend including methyl eugenol performed numerically the best in attracting E. hirta compared with the blends with eugenol or isoeugenol, which results are congruent with the earlier findings on C. a. aurata and P. cuprea. Our work resulted in a single optimized attractant combination for all three cetoniin species that includes 2‐phenethyl alcohol, methyl eugenol and (E)‐anethol.