Environmentally vulnerable noble chafers exhibit unusual pheromone-mediated behaviour

Area of Science:

• Chemical Ecology
• Insect Conservation
• Behavioral Ecology

Background:

• Conserving vulnerable insect species necessitates understanding their ecology.
• Pheromones offer non-destructive monitoring tools for scarab beetles, aiding range mapping in Europe.
• The noble chafer (Gnorimus nobilis) is a conservation concern and a red-listed UK priority species.

Purpose of the Study:

• Investigate the chemical and behavioral ecology of the noble chafer.
• Identify potential pheromones for monitoring Gnorimus nobilis populations.
• Provide a model for non-invasive surveillance of cryptic insect species.

Main Methods:

• Electrophysiological recordings to detect olfactory responses.
• Behavioral assays to measure insect responses to chemical stimuli.
• Field trials in the UK to validate findings.

Main Results:

• Identified 2-propyl (E)-3-hexenoate as a compound produced by both sexes of Gnorimus nobilis.
• Observed that 2-propyl (E)-3-hexenoate attracts only male noble chafers.
• Classified the compound as an aggregation pheromone, potentially representing an intermediate evolutionary stage.

Conclusions:

• 2-propyl (E)-3-hexenoate serves as an aggregation pheromone for Gnorimus nobilis.
• This finding supports the development of non-invasive monitoring techniques for vulnerable insects.
• The study provides a model for understanding chemical signaling in conservation efforts.