Improved mortality of the Formosan subterranean termite by fungi, when amended with cuticle-degrading enzymes or eicosanoid biosynthesis inhibitors

Authors: Wright, Maureen; Lax, Alan

Submitted to: Folia Microbiologica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2015
Publication Date: 1/1/2016
Citation: Wright, M.S., Lax, A.R. 2016. Improved mortality of the Formosan subterranean termite by fungi, when amended with cuticle-degrading enzymes or eicosanoid biosynthesis inhibitors. Folia Microbiologica. 61(1):73-83.

Interpretive Summary: Subterranean termites cause several billion dollars in damage and prevention costs in the United States annually. The Formosan subterranean termite is responsible for a large and growing proportion of the cost. The identification of novel microbes which cause mortality of Formosan subterranean termites can expand the options available to treat infestations. This work reports the screening of a fungus for its ability to kill Formosan subterranean termites and the increased effect it has when combined with chemicals that degrade the outer surface of the termite.

Technical Abstract: Formosan subterranean termites (FST) were exposed to spores of the fungus Beauveria pseudobassiana (Bpb) strain 8046 to determine virulence of the fungus. Once Bpb was determined to cause mortality of FST it was combined with enzymes capable of degrading the insect cuticle to measure the potential to enhance infection of the fungus. Bpb was found to cause 100% mortality of FST by day 7 at a concentration of 109 spores/ ml. Concentrations of 103 and 106 did not cause significantly higher mortality of FST than the control on days 7, 14 or 21. When Bpb was applied at a sublethal dose of 107 spores/ml in combination with enzymes it was found that both proteinases and the chitinase tested significantly increased mortality over the fungus alone. The two lipases tested did not enhance mortality of the fungus.