Common pheromone use among host-associated populations of the browntail moth, Euproctis chrysorrhoea (Lepidoptera: erebidae), displaying different adult phenologies

Authors: FRAGO, ENRIC - Cirad, France; WANG, HONG-LEI - Lund University; SVENSSON, GLENN - Lund University; MARQUES, JOANA - Lund University; HODAR, JOSE - Universidad De Granada; BOETTNER, JEFF - University Of Massachusetts; CIORNEI, CONSTANTIN - University Of Agricultural Sciences And Veterinary Medicine - Romania; DORMONT, LAURENT - University Of Montpellier; ELKINTON, JOE - University Of Massachusetts; FRANZEN, MARKUS - Helmholtz Centre; Khrimian, Ashot; MARIANELLI, LEONARDO - Research Centre For Agrobiology And Pedology; MARZIALLI, LORENZO - Tuscany Regional Health Agency; MAS, HUGO - Centre Of Applied Forest Research (CIEF); PEREZ-LAORGA, EDUARDO - Centre Of Applied Forest Research (CIEF); PEREZ-LOPEZ, JAVIER - Parque De Las Ciencias (THE SCIENCE PARK); ROQUES, ALAIN - Inra- Site D'Orleans Unite De Zoologie Forestiere; SIMONCA, VASILE - University Of Agricultural Sciences And Veterinary Medicine - Romania; ANDERBRANT, OLLE - Lund University

Submitted to: Entomologia Generalis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/28/2019
Publication Date: 12/9/2019
Citation: Frago, E., Wang, H., Svensson, G.P., Marques, J.F., Hodar, J.A., Boettner, J., Ciornei, C., Dormont, L., Elkinton, J., Franzen, M., Khrimian, A., Marianelli, L., Marzialli, L., Mas, H., Perez-Laorga, E., Perez-Lopez, J., Roques, A., Simonca, V., Anderbrant, O. 2019. Common pheromone use among host-associated populations of the browntail moth, Euproctis chrysorrhoea (Lepidoptera: erebidae), displaying different adult phenologies . Entomologia Generalis. 39(3-4):295-306.

Interpretive Summary: Insect pests cause a significant damage to crops and forest, and monitoring their populations aids greatly to reducing the pesticide use and biological control. Pheromones, or chemicals that trigger a natural behavioral response in another member of the same species, are commonly used as baits for sampling inset populations. Host plan utilization has been advocated as a major factor in the diversification of plant-feeding insects, including the browntail moth. Here, we compared the sex pheromone from different populations of browntail moth and used pheromone trapping data to build a model of the animal periodic life cycle. We found that despite the fact that different populations of browntail moth produce and use the same pheromone, males fly on average 25 days earlier in those populations where larvae feed on an evergreen shrub called “strawberry tree” compared to those that feed on Quercus spp. The results of this study are of interest to chemical ecologists and entomologists involved in the research of potential pest control compounds, and to state and federal agencies involved in monitoring and controlling insect pests of agriculture and forest.

Technical Abstract: The diversity of herbivorous insects may arise from colonisation and subsequent specialization on different host plants. Such specialization requires changes in several traits in the insect, which may lead to host race formation if they reduce gene flow among populations that feed on different plants. Behavioural changes may play a relevant role in host race formation, for example if different races evolve distinct sexual communication signals or adult phenology. Previous research has revealed different host races in the browntail moth, Euproctis chrysorrhoea. Here, we compare the sex pheromone of different host-associated populations of this species, and we also use pheromone trapping data from the field to build a phenological model that tests whether different races differ in their adult flight period. The chemical and electrophysiological analyses revealed that E. chrysorrhoea races on Quercus spp. and on Arbutus unedo use the same sex pheromone component for mate finding. Despite this, our trapping data showed that males fly on average 25 days earlier in those populations where larvae feed on A. unedo compared to those that feed on oak species. Although we did not find divergence in the sexual signal, the temporal isolation described here likely underlies host race formation in E. chrysorrhoea, a mechanism that has been described in a limited number of insect species.