Control of subterranean termite (Isoptera: Rhinotermitidae) infestations in wooden power poles using bandages containing fipronil

A trial was conducted to assess the effectiveness of pole bandages containing fipronil for controlling subterranean termites in power poles. Bandages were applied to 39 in-service termite infested poles located in country New South Wales and around Sydney. A further 21 termite infested poles in the same areas were used as untreated controls. Poles were partially excavated and bandages attached below ground. After poles were re-buried the backfill was moistened with 8 L of water. Twelve months after treatment all poles were inspected for termites (as an indication of treatment efficacy). With treated poles, the quantity of original material lost from bandages (‘bandage depletion’) was estimated and soil samples were collected to determine fipronil concentration. After 17 months, country poles were again inspected to determine infestation status and the extent of bandage depletion. Inspection results were analysed by logistic regression. One model was fitted to all the data using treatment, location and time as factors. The odds of infestation (i.e. probability of pole being infested/probability of pole not being infested) were higher for controls than for treated poles. Odds of infestation were also higher in Sydney than in the country. Another model was fitted for data where treatment was applied using location, bandage depletion and time as factors. In this model the odds of infestation fell as bandage depletion increased, probably as a result of increasing fipronil contamination of soil around the pole. Concentrations of soil fipronil were highly variable from pole to pole. A correspondence was noted between higher mean soil fipronil levels and better termite control in country poles. This study has shown that pole bandages containing fipronil can provide termite control on par with conventional soil treatment techniques.