The Use of Entomopathogenic Fungi for Control of Termites

Abstract

Termites are major pests of timber and timber products which live in warm, humid environments that are conducive to the development and spread of entomopathogenic fungi. Laboratory studies have shown that termite species are highly susceptible to entomopathogenic fungi from genera including the most commonly studied species, Metarhizium anisopliae and Beauveria bassiana . There appears to be very little host specificity among fungal isolates with many isolates being highly virulent to many species of termites. The grooming and other social interactions between termites are seen to have the potential to spread the fungus through the colony, allowing for colony control by the treatment of remote feeding sites. However, factors such as avoidance of the fungus conidia by the termites, the removal and burial of fungus-killed termites, together with defensive secretions and inhibitory components in termite frass and the possibility of humoral resistance may limit the spread of the disease in the colony. Field studies have shown mixed results. Direct application of fungi to nests has resulted in complete colony mortality, but studies where feeding sites or bait stations have been treated with fungus have yet to show similar success. The effectiveness of termite control in urban pest management, particularly in structural timber and dwellings, has yet to be reported in detail. Such studies require the examination of the complex relationships between dose, speed of kill, virulence, horizontal transmission and ultimate colony death, combined with avoidance and recognition factors, and survival of the fungi under field conditions. There is currently one commercial product available in the USA.