Interactions between Subterranean Termites, Blue Stain Fungi, and Bark Beetles
Blue stain (Ophiostomatoid) fungi are ubiquitous from the arctic to the tropics and are vectored to trees by bark beetles and their phoretic mites. The fungi reduce the value of timber aesthetically by discoloring the sapwood, but do not cause any structural damage to wood.
Recently, my lab discovered that wood from trees killed and inoculated with blue stain fungi by bark beetles elicited a positive feeding response by native and non-native (Formosan) subterranean termites. This finding is the first instance of an interaction between subterranean termites and a non-decay fungus and the first direct link between bark beetles, a primary herbivore of pines, and subterranean termites, the primary invertebrate decomposers of pines in many forest ecosystems.
The implications of the fungally-mediated link between termites (an ecosystem engineer) and bark beetles (a keystone herbivore in many forests) are far-reaching. Landscape-scale carbon and nutrient cycles in many forest ecosystems may be mediated by this important multi-trophic interaction. Our experiments investigating the differences in decomposition rates, invertebrate communities, and nutrient availability between unstained and blue stained trees in a natural environment will help uncover novel ecological links between above- and belowground systems in forest ecosystems.