Exploration in natural areas of Hong Kong, China, for natural enemies of the Formosan subterranean termite, coptotermes formosanus shiraki

Abstract

Establishing relationship between the parasitoid and Coptotermes formosanus Shiraki may discover the potential of this parasitoid as biological control agent. Field baiting experiments showed that C. formosanus had preference for pine wood stakes over tissue paper rolls and their foraging population had no significant correlation with the ambient temperature; but do have relationship with relative humidity. C. formosanus, the Formosan subterranean termite (FST) is an important wood structure pest in its native and exotic ranges. Survey screening for both the known available agents and new indigenous organisms able to control FST population in the natural areas of Hong Kong was conducted. Two micro-fungi and an dipteran parasitoid were found associated with termites in the natural environment. Termitaria spp. and Antennopsis spp. are micro-fungi found on the integument of FST. Both of the fungi received little attention from the research field after their discoveries, but they have been accepted as ectoparasites on termites throughout the years. Therefore, their potential as control agents on FST population is assessed in this project. TEM examination showed that of the two species, only Termitaria spp. had haustorial cells invading through the insect cuticle. With its parasitic characteristic, Termitaria spp. is believed to be biotrophic. If a high proportion of the termite nest population is infected, this could have an adverse effect on the colony. Verticia fasciventris, a dipteran parasitoid, was found parasitized in termite, Macrotermes barneyi Light, soldier head. The parasitoid fed on soldier head muscle and enlarged its head capsule. Eventually, the infected soldiers were killed with an empty head. Then, the dipteran larvae left the soldier hosts and emerged into adult flies. If this parasitoid is also found to be a parasite of FST, it may then act as a biological control agent to FST.

Date of Award	14 Jul 2006
Original language	English
Awarding Institution	City University of Hong Kong
Supervisor	Desmond Keith O'TOOLE (Supervisor)