A Method for Trapping Hylobius abietis (L.) with a Standardized Bait and Its Potential for Forecasting Seedling Damage

A method for trapping walking Hylobius abietis (L.) (Coleoptera: Curculionidae) was developed and evaluated. Synergism between a-pinene and ethanol in attracting H. abietis was confirmed. The effects of varying release rates of these substances and of adding other host terpenes were studied. A simple bait was developed containing a-pinene and ethanol released from separate vials. The correlation between trap catch and seedling damage was estimated during May, June, and August on 1-, 2-, and 3-year-old clear-cuttings. In May and June, population levels were relatively high on all clear-cuttings and no significant correlations were found. The August experiment showed a strong positive correlation between catch and damage. The percentage damaged seedlings per captured weevil was considerably higher in August than in May or June. Possibilities for developing a system for forecasting seedling damage using this trapping method are discussed.