Efficacy of didecyldimethylammonium chloride against subterranean termites (Isoptera) in Australia

A laboratory bioassay was conducted on the ability of didecyldimethylammonium chloride (DDAC) to protectPinus radiata D. Don wood specimens from attack by two of Australia's most economically important species of subterranean termite,Mastotermes darwiniensis Froggatt (Mastotermitidae) andCoptotermes acinaciformis (Froggatt) (Rhinotermitidae). Sapwood specimens ofP. radiata, treated to achieve nominal retentions of 0.5, 1.0, 2.0, 4.0 and 6.0 kg/m³ of active ingredient, were bioassayed against each of these termite species for four and eight weeks, respectively. Mean percentage mass loss data showed that between 2.0 and 4.0 kg/m³ of DDAC was necessary to protect specimens from significant attack by both species of termite. The usefulness of DDAC as a termiticide for timber, particularly in the above-ground situation, is discussed.With one table and one figure