J. Sweeney, P. de Groot, L. MacDonald, S. Smith,C. Coquempot, M. Kenis, and J. Gutowski
Natural Resources Canada, Canadian Forest Service, Fredericton, N.B.
SERG Project #2002/01
Year of Project: 2002
Report Received: 2003
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Abstract
The brown spruce longhorn beetle, Tetropium fuscum Fabr. (Coleoptera: Cerambycidae), is a quarantine pest recently found established near the port of Halifax, Nova Scotia. In its native Europe, T. fuscum mainly attacks weakened Norway spruce, but in Nova Scotia it is infesting and killing apparently healthy red spruce. An attractant-baited trap capable of detecting the presence of T. fuscum at low densities would be extremely useful for surveys and monitoring of the eradication effort in Halifax and also for early detection of T. fuscum at other sites at risk of new introductions. In 2001, we analyzed cortical volatiles collected in situ from T. fuscum-infested red spruce to determine the relative concentrations and enantiomer ratios of chiral compounds present. This information was used to create a synthetic “spruce blend” lure that was tested for efficacy in capturing T. fuscum and other Tetropium species with and without the addition of an ethanol lure in various trap designs. In 2002 field trials, traps baited with spruce blend captured significantly more T. fuscum (in Nova Scotia) and T. castaneum (in Switzerland) than unbaited traps. The addition of an ethanol lure to spruce blend-baited traps significantly increased capture of T. fuscum (in Nova Scotia and Poland) and T. castaneum (in Poland). The prototype Colossus-dry traps caught the most T. fuscum, but mean catch did not differ significantly among the various trap types tested.
Cortical volatiles were sampled in situ at regular intervals from May to August 2002 from healthy red and Norway spruce in Ontario and New Brunswick and also from stressed (girdled in spring) red and Norway spruce in New Brunswick to identify additional components or blends that may enhance attraction of T. fuscum. Host volatile analyses to date indicate a marked difference between red and Norway spruce in the percentage of (-)-beta-pinene present and significantly higher amounts of (-)-beta-pinene in the girdled trees compared to ungirdled trees for both spruce species.
Our results indicate that the addition of an ethanol lure synergizes attraction of the spruce blend to both T. fuscum and T. castaneum, another wood-boring insect on the Canadian Food Inspection Agency’s list of unwanted quarantine pests. The probability of detecting T. fuscum and T. castaneum in areas where either is present will be increased by the addition of an ethanol lure to cross-vane traps baited with spruce blend.