Effect of Flooding on the Survival of Formosan Subterranean Termites (Isoptera: Rhinotermitidae) in Laboratory Tests

Underground monitoring stations were active with Formosan subterranean termites, Coptotermes formosanus Shiraki, less than a month after City Park, an urban park in New Orleans, Louisiana, was inundated with 0.5 to 2.5 meters of flood water. This study examines whether C. formosanus are able to survive inundation by finding air pockets in either wood or their gallery system in the soil and whether termites move up from the substrate to higher ground in response to rising water. We found no evidence that termites are able to survive in their gallery system or within wood after submersion, and no evidence that termites attempt to move up from the substrate in order to escape rising water. However, significant numbers of termites located within the hollowed-out core of a wood block at the time of the flooding were able to escape slowly rising water. Formosan subterranean termite colonies most likely survived the flooding of City Park because these colonies were living within trees at the time of the flood. The construction of carton nests within the hollowed-out trunks of living trees may be a behavioral adaptation to survive flooding.