The role of (wood degrading?) fungal volatiles in the host location process of Sirex noctilio and its parasitod, Ibalia leucospoides.

MARTINEZ ANDRES; JOFRE, N; VILLACIDE, JM; CORLEY, JC

Bariloche

Congreso; IUFRO 07.03.05 - 07.03.12 Joint Meeting; 2015

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The woodboring wasp Sirexnoctilio (Hymenoptera; Siricidae) and its parasitod Ibalia leucospoides (Hymenoptera: Ibaliidae) have been focus ofresearch in the past years. On one hand Sirexnoctilio infects susceptible pine trees by inoculating mycelia of itsobligated symbiont fungi (Amylostereum areolatum); larvae need thefungus to feed while the fungus needs wasps to disperse and to initially weakenthe tree by the inoculation of a phytotoxic venom. On the other hand, I. leucospoides adult females have ashort window of time to locate eggs and young larvae concealed under the woodbefore they burrow too deep. In order to increase their fitness, while searchingfor suitable ovisposition substrates, both species must use reliable andpredictable cues such as smells derived from the host-plant, from the hoststhemselves or associated organisms. Here we investigate and discuss the rolethat volatiles produced by the fungal symbiont A. areolatum has in the host location process (i.e. susceptibletrees for S. noctlio and eggs/larvaeof the parasitod) for both species. Results indicate that A. areolatum volatiles are not only attractive to both wasps andimportant in but could also be important for the parasitod hos host suitabilityassessment.