sentences:  Each year, the fungus kills the callus material formed by the tree and invades more cambium during the growing season.During the summer months, the fungus is also able to produce asexual spores called conidia that are dispersed by the wind to be used as secondary inoculum to infect other maple trees in the area.Upon dispersal, they potentially land on a susceptible host which induces the spore to germinate and produce mycelia.