Symbiosis: effects of a mutualistic fungus upon the growth and reproduction of Xyleborus ferrugineus.

Xyleborus ferrugineus beetles developed from asymbiontic eggs through the adult stage on a sterilized meridic diet, but the resulting adults reproduced only when a mutualistic fungus was inoculated into the diet. Beetles with bacterial symbionts still required the fungus for reproduction on a second meridic diet.