L. Maistrello et al., Effects of nootkatone and a borate compound on formosan subterranean termite (Isoptera : Rhinotermitidae) and its symbiont protozoa, J ENTOM SCI, 36(3), 2001, pp. 229-236
Wood treated with disodium octaborate tetrahydrate, with nootkatone, a natu
ral extract isolated from vetiver oil, or with both nootkatone and disodium
octaborate tetrahydrate was tested for effects on Coptotermes formosanus S
hiraki and its hindgut flagellates. Results demonstrated that after 7 d dis
odium octaborate tetrahydrate-treated wood induced high termite mortality a
nd almost complete loss of flagellates, confirming the toxicity of borates
to these termites. Wood treated with nootkatone alone or with the nootkaton
e-borate mix was consumed in significantly lower amounts than the control,
and termite survival was comparable to results obtained for starved termite
s. A significant progressive reduction in the total number of protozoa was
observed for all groups, including the controls. We conclude that nootkaton
e acts as a feeding deterrent, inducing starvation that results in almost a
complete loss of Pseudotrichonympha grassii Koidzumi, the most important f
lagellate species for cellulose digestion in this termite.