Populus-grandidentata
Guides
Anisandrus obesus
Anisandrus obesus is an ambrosia beetle native to eastern North America that specializes in boring into the sapwood of Big Tooth Aspen (Populus grandidentata). Females construct characteristic gallery systems consisting of a single entrance tunnel approximately 7 mm deep followed by two lateral tunnels parallel to the wood surface. The species maintains an obligate symbiosis with ambrosia fungi, which larvae consume without expanding parental galleries. Progeny exhibit strongly female-biased sex ratios (approximately 6:1), with only females emerging in spring to disperse and attack new hosts.