Evaluation of grease, an industrial machinery lubricant, as an alternative to ant repellants for invasive fruit flies surveillance traps

Predation of insects attracted by surveillance traps inhibits accurate evaluation of invasive pests. Prevention of intrusion into the traps by ants is very important because they can carry away the whole insect body, the evidence of the pest existence. Since the production of Tree Tanglefoot Insect Barrier® tube （Tangle） used as an ant repellent in Okinawa has been discontinued, we evaluated the effectiveness of a lubricant grease （Sumiplex MP, No. 0; Grease）, used for industrial machinery, as an alternative ant repellent to Tangle. We placed frozen-dead melon flies, Zeugodacus cucurbitae, in traps set in the field and collected them two weeks later to evaluate predatory damage. The results showed Grease was as effective or even more effective as Tangle as an ant repellent. No significant difference in damage rate per fly was observed between the materials. In addition, with regard to disappearance damage, traps with Grease were slightly but significantly less damaging than traps with Tangle, in which the fly body was completely carried away. Furthermore, we compared Grease with Tangle with regard to ease of handling and outdoor durability and concluded Grease is an effective alternative material.