Responses of the Formosan subterranean termite (Isoptera: Rhinotermitidae) to wood blocks inoculated with lignin-degrading fungi

This study examined how differences in the light/dark cycle and in the length of time that wood blocks were decayed by two species of basidiomycete fungi, Marasmiellus troyanus (Murrill) Singer and Phanerochaete chrysosporium Burdsall, affected the behavior of the Formosan subterranean termite, Coptotermes formosanus Shiraki. The response of the Formosan subterranean termite to fungus-inoculated wood blocks was affected by both the length of time of decay and the light/dark cycle under which the fungus-inoculated wood blocks were kept. Under most of the conditions tested, termites were more likely to aggregate on wood blocks inoculated with M. troyanus versus control blocks than on wood blocks inoculated with P. chrysosporium compared with controls. However, a comparison of weight loss of wood blocks due to fungal decay over a 12-week period determined that P. chrysosporium actually caused significantly greater weight loss in blocks than M. troyanus. Therefore, termites appear to be responding to either differences in the chemicals produced by the fungi or to differences in how the two fungi affect the chemical composition of the wood, rather than merely to differences in the rate of decay of the wood by the two fungal species.