Chemical ecology of Sirex noctilio and its symbiotic fungus Amylostereum areolatum grown on different substrates

MASAGUÉ, S.; FERNANDEZ, P.C.; DEVESCOVI, F.; SEGURA, D.F.; VILLACIDE, K.; CORLEY, J.C.; MARTINEZ, A.

Buenos Aires

Congreso; 6to Congreso de la Asociación Latinoamericana de Ecología Química; 2021

Asociación Latinoamericana de Ecología Química

The woodwasp, Sirex noctilio (Fabricius) (Hymenoptera: Siricidae), is an invasive species that has colonized most of the regions of the world where Pinus spp. is grown/cultivated. Since its establishment in Argentina in the 1980s, the wasp has become one of the main insect pests affecting the forestry industry. To date, an environmentally sound species-specific monitoring and control tool based on semiochemicals is lacking for this pest. To this end, knowledge on the sensory ecology of S. noctilio, specifically in terms of the chemical volatiles involved in eliciting attractive responses, is much needed. Previous studies carried out in our laboratory have shown a strong attraction of S. noctilio females to the obligate symbiotic fungus Amylostereum areolatum. In this context, our objective is to evaluate the response of S. noctilio females to different volatile stimuli released by A. areolatum grown in different ubstrates: artificial agar-based culture medium and two of the pine species most widely cultivated in Patagonia (Pinus contorta and Pinus ponderosa). Through 4-way olfactometric bioassays, we were able to determine that there is a clear hierarchy in relation to the preferences of the females towards the different stimuli evaluated, being the semiochemicals released by the fungus cultivated in P. contorta the most important. GC-EAD and GC-MS studies were performed to analyze the compounds emitted by the different sources and address the antennal response of females. The results are discussed in the context of possible species-specific semiochemical-based monitoring and control tools, and the directions of proposed future research.