This invention relates to use of naphthalenic compounds as effective bait toxicants for their use in the control of termites.
Damage in the United States attributable to subterranean termites is now estimated to be in excess of one billion dollars a year. All wooden or wood-containing structures are potentially affected, including homes, outbuildings, fences, utility poles, railway sleepers, boats, bridges, retaining walls and even living trees. Since their introduction to the United States within the last half-century, Formosan subterranean termites (FST), Coptotermes formosanus (Shiraki), have become one of the most destructive pests in the contiguous United States. Reasons for this include their massive colonies which can contain tens of millions of individuals, their ability to attack several species of living trees, and their high level of reproduction.
The most successful existing methods for control of subterranean termites are preventive rather than remedial. These include barrier treatments to structures and the pre-emptive treatment of wood materials with chemicals to prevent termite attack. These methods, however, have drawbacks. Physical barriers are not compatible for retrofitting on many existing constructions and may not be completely effective, and chemical treatments are only partially effective and last only about five years.
Low toxicity baits utilizing growth regulators have shown success in reducing damage caused by subterranean termites, with diflubenzuron and hexaflumuron having been particularly effective in suppressing colonies of C. formosanus and Reticulitermes spp. Bait matrices utilized for the baits have consisted of cardboard, filter paper, pine wood, pure cellulose, and recently the use of a nutritionally based matrix. Depending on the species of termite, these matrices have shown to be effective toxicant carriers. Chen et al. (Naphthalene in Formosan Termite Carton Nests; Journal Agricultural Food Chemistry, Vol. 46, No. 6, 1998) disclose the presence of naphthalene in termite carton nests and postulated that it might constitute a unique chemical defense strategy for Formosan termites. Grace et al. (Evaluation of the Termite Resistance of Wood Pressure Treated with Copper Naphthenate; Forest Products Journal, Vol. 43, No. 11/12, November/December 1993) teaches that copper naphthenate is not only toxic to termites but is also highly repellent to them.
While various methodologies and compositions exist for the monitoring and control of termites, there remains a need for the creation of improved tools in this area.
Therefore, it is an object of this invention to provide alternative compounds as bait active ingredients effective as toxicants for termites.
Yet another object is to provide compositions and methods for the effective control of termite populations.