Survivorship, tunneling and feeding behaviors of Coptotermes formosanus (Isoptera: Rhinotermitidae) in response to 2′-acetonaphthone-treated sand
Abstract
In laboratory tests, 2′-acetonaphthone was incorporated into sand at different concentrations (4.16-200 mg kg-1) and evaluated for survivorship, feeding and tunneling effects on the Formosan subterranean termite, Coptotermes formosanus Shiraki. 2′-Acetonaphthone at 8.33 mg kg-1 sand significantly reduced survivorship (89-94%), tunnel area (68-91%) and food consumption (84-100%) compared with the control. Most of the dead workers were found at the release point and a few had traveled to the surface of the treated sand. Malformed workers (≤27%) with an unexpected symptom of molting failure were observed, particularly at the lowest concentration tested (4.16 mg kg-1). In choice assays, threshold concentration for significant reduction in survivorship, tunnel construction in treated sand and food consumption in the treated-sand side was 8.33 mg kg -1 with termites collected from New Orleans, LA and 35.0 mg kg -1 for those from Lake Charles, LA. Termites actively fed and tunneled in the untreated sand, whereas 2′-acetonaphthone at 140 mg kg-1 completely inhibited consumption of food placed on the treated sand.