Main content area

Elevated Carbon Dioxide Concentration Reduces Alarm Signaling in Aphids

Boullis, Antoine, Fassotte, Bérénice, Sarles, Landry, Lognay, Georges, Heuskin, Stéphanie, Vanderplanck, Maryse, Bartram, Stefan, Haubruge, Eric, Francis, Frédéric, Verheggen, François J.
Journal of chemical ecology 2017 v.43 no.2 pp. 164-171
Acyrthosiphon pisum, active ingredients, alarm pheromones, carbon dioxide, carbon dioxide enrichment, chemical communication, escape behavior, greenhouse gases, insects, neurons, predation, rearing, smell, trophic levels
Insects often rely on olfaction to communicate with conspecifics. While the chemical language of insects has been deciphered in recent decades, few studies have assessed how changes in atmospheric greenhouse gas concentrations might impact pheromonal communication in insects. Here, we hypothesize that changes in the concentration of atmospheric carbon dioxide affect the whole dynamics of alarm signaling in aphids, including: (1) the production of the active compound (E)-β-farnesene (Eβf), (2) emission behavior when under attack, (3) perception by the olfactory apparatus, and (4) the escape response. We reared two strains of the pea aphid, Acyrthosiphon pisum, under ambient and elevated CO₂ concentrations over several generations. We found that an increase in CO₂ concentration reduced the production (i.e., individual content) and emission (released under predation events) of Eβf. While no difference in Eβf neuronal perception was observed, we found that an increase in CO₂ strongly reduced the escape behavior expressed by an aphid colony following exposure to natural doses of alarm pheromone. In conclusion, our results confirm that changes to greenhouse gases impact chemical communication in the pea aphid, and could potentially have a cascade effect on interactions with higher trophic levels.