CARBON-DIOXIDE AS A POTENTIAL FUMIGANT FOR TERMITE CONTROL

Formosan subterranean termites, Coptotermes formosanus Shiraki, were e xposed to greater than or equal to 95% or 50% carbon dioxide atmospher es for intervals of 24-120 h at 26(+/- 3)degrees C. A 24-h exposure to greater than or equal to 95% carbon dioxide caused significant termit e mortality, but 60 h were required for complete mortality. Exposure t o 50% carbon dioxide for 60 h resulted in approximately 70% termite mo rtality, while complete mortality was recorded after 120 h. When termi tes were sealed in wooden blocks (90 x 90 x 152 mm), 72-96 h exposure to greater than or equal to 95% carbon dioxide was necessary for compl ete control. A limited study with Cryptotermes brevis (Walker) suggest ed that this drywood termite is also susceptible to carbon dioxide fum igation, although slightly longer exposures may be required than with C. formosanus. Carbon dioxide-modified atmospheres are a viable altern ative to conventional fumigants for vault fumigation of termite-infest ed materials, and may also be applicable to larger-scale fumigations t o control structural pests.