Deltamethrin effectiveness against subterranean termite attack on wood under natural conditions
P A Zanotto
On fighting subterranean termites on wood, out of ground contact, the synthetic pyrethroid Deltamethrin shows positive aspects such as its efficiency and low mammalian toxicity. To evaluate its performance in conditions very similar to those in service use, specimens of Pinus sp were treated with solutions of Deltamethrin diluted in "white spirits" at 0.005% (w/w) and 0.01% (w/w) and exposed in a cottage higly infested with Heterotermes tenuis (Hagen, 1858) colonies. Previously to this exposition, the treated specimens were conditioned for nine months under two different environmental conditions: dry and damp. After the second inspection, performed sixteen months after the exposition to termite attack, it was found that only the specimens which had been subjected to damp conditions were attacked, most of them treated using the 0.005% (w/w) concentration level. The specimens treated but conditioned in a dry ambient were not attacked by subterranean termites.