Improved management of termites to protect Japanese homes

Abstract:
Termites are considered to be urban pests in Japan, which has a long history of combating the two most economically important subterranean termites [Reticulitermes speratus (Kolbe) and Coptotermes formosanus Shiraki], since Japanese houses are made principally of wood. Approximately half of new homes are still being built using wood- frame construction. Apart from treatment of the soil and lumber with more environmentally benign termiticides, information on the ecology of Japanese termites, coupled with experience, may be helpful for the development of a new termite management technology. Recent experimental studies by Japanese scientists have produced some interesting evidence: (1) the population size of R. speratus is much larger than previous estimates, (2) intestinal protozoa play specific roles in the supply of nutrition to C. formosanus, (3) cellulase excreted by termites themselves participates in wood decomposition, (4) colony recognition mediated by intestinal bacteria and colony fusion may occur in R. speratus, (5) a symbiotic sclerotium-forming fungus helps to protect termite eggs from natural enemies, (6) C. formosanus and R. speratus differ with regard to their requirements for water, (7) a baiting system may be useful for controlling infestations of both C. formosanus and R. speratus, (8) termites show higher penetrating activity in soil rich in available phosphate, organic matter and humic substances, and (9) timber that is categorized as durable (resistant against termites), is not as durable if it was grown on a plantation. These findings may be linked to the development of an integrated termite management (ITM) approach. For example, protozoicides and bactericides may be useful for controlling termite infestations if the termites could be induced to ingest them and deliver them to their nestmates through grooming and trophallaxis. A bating system can contribute to the reduced use of chemicals when used consistent with the characteristic foraging dynamics of the target termite species, which results in less environmental impact. This review describes the possibility of new approaches to termite prevention and control with an emphasis on the situation in Japan.