Three Amylostereum species are symbionts of wood wasps in the genera Sirex , Urocerus , and Xoanon , which infest conifers . The female wood wasps deposit their eggs together with fungal spores and mucus in trees , and the fungus is eaten by the wasp 's larva as food . The fungus propagate vegetatively through the formation of asexual spores in newly emerged females that are stored in special structures adapted for the transport of symbiotic fungi . The A. areolatum – Sirex woodwasp ( S. noctilio ) symbiont complex have been studied extensively because of its potential to cause substantial economic losses in the forestry industry , particularly in non @-@ native regions .