Scientific Note—First records of Cossonus americanus Buchanan and Rhyncolus dilatatus Casey (Coleoptera: Curculionidae) in Idaho

摘要

Snags of two tree species, Douglas-fir (Pseudotsuga memiesii var. glauca (Mayr) Sudw.) and grand fir (Abies grandis (Dougl.) Lindl.) were created within two harvested units on the University of Idaho Experimental Forest, Latah County, Idaho during January of 2002. The snags were created by severing tree boles using a single-grip, cut-to-length harvester. The boles were severed at a height of not less then 3 m and the top of the trees were removed along with the other harvested material. A total of 30of these created snags (15 Douglas-firs and 15 grand firs) had 12-unit Lindgren funnel traps (Lindgren 1983) placed directly adjacent to them (distance <= 10 cm), suspended on metal poles located on the eastern aspect of the bole approximately 2 m abovethe ground. The Douglas-fir snags (height = 5.0 ± 2.0 m and diameter at breast height = 38 ± 3 cm) and grand fir snags (height = 4.6 ± 1.2 m and diameter at breast height = 33 ± 2 cm) were similar in size. The Lindgren funnel traps were not baited,but did have Vapona~R killing strips placed in the collection cups. Twenty traps were placed in the field on 15 May 2002 and the remaining 10 traps were placed in the field on 22 May 2002. Insects were collected from each trap at approximately weekly intervals until 26 September 2002. After each collection period, the beetles were sorted and identified.