Transfer of Termiticidal Dust Compounds and their Effects on Symbiotic Protozoa of Reticulitermes flavipes (Kollar)
F Green III, R A Arango, G Esenther
Dusting of termites in situ has been used as a control measure for decades; however environmental awareness of the toxicity of certain compounds now limits their use (eg arsenical dusts). Our laboratory is in the process of suppressing an isolated colony of Reticulitermes flavipes (Kollar) from a small village of 250 homes in mid-central Wisconsin (Endeavor, WI). Initial treatment of the colony involved the use of 200 Microgen bait cartridges containing 0.25% diflubenzuron. The presence of many living termites occupying bait stations throughout the season prompted the addition of various dusting compounds, such as boron, N-N’naptahaloylhydroxylamine (NHA) and other dusts to aide in colony elimination. This laboratory study explores the efficacy of various insecticidal dusts to kill termites as well as to transfer the insecticide to nest mates. Mortality after primary (direct) dusting was found to occur with sodium borax, zinc borate, concrobium polymer (CP) and
NHA in 7, 9, 9 and 21 days respectively. However, the ability to cause mortality to 25 un-dusted termites was impaired in the concrobium group and delayed in others. Further tests were performed to determine the mechanism of transfer by examining the survival rates of the symbiotic flagellated protists in the termite hindgut over time after dusting to determine if termiticidal dusts were killing the protozoa necessary for cellulose digestion. Possible mechanisms of mortality are discussed as well as the potential of using dusting compounds in termite treatment or eradication.