Comparative response of Reticulitermes flavipes and Coptotermes formosanus to borate soil treatments
J K Grace
Eastern (Reticulitermes flavipes [Kollarl]) and Formosan (Coptotermes formosanus Shiraki) subterranean termite workers (Isoptera: Rhinotermitidae) were exposed to borate-treated sand in an indirect exposure tunneling assay in the laboratory. In the ten day assay period, both termite species readily penetrated sand containing 5000, 10000, or 15000 ppm (wt. of compound / wt. of sand) disodium octaborate tetrahydrate (Tim-BorÒ) or zinc borate (Firebrake ZB-FineÒ). With Reticulitermes flavipes, significant mortality (85-93%) resulted from workers tunneling through sand treated with 5000 ppm disodium octaborate tetrahydrate (higher concentrations were also effective), or 15000 ppm zinc borate. Responses of Coptotermes formosanus workers were lesser and more variable, with only concentrations of 10000 and 15000 ppm zinc borate resulting in mortality 70-89%) significantly different from that in the control groups. These results suggest that differences between these two species in tunneling behavior may reduce exposure of Coptotermes formosanus to the borate-treated sand.