Submitted to: Journal of British Columbia Entomological Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 31, 2001
Publication Date: December 15, 2001
Citation: Horton, D.R., Landolt, P.J. 2002. Use of Japanese beetle traps to monitor flight of the Pacific coast wireworm, Limonius canus (Coleoptera: Elateridae), and effects of trap height and color. Journal of the Entomological Society of British Columbia. 98:235-242. Interpretive Summary: Click beetles are serious pests in a variety of vegetable crops. Controlling these pests is made more difficult by a lack of effective tools with which to monitor the adult beetle. This study shows that flight traps developed originally to monitor Japanese beetles can be used to monitor adult click beetles. We showed that efficiency of the traps depends upon trap color, with yellow and white traps outperforming traps of other colors. Also, height of the trap above ground affects trap catch. Catch was better at lower heights than in traps placed at higher elevations above ground. Results reported here show that it is possible to sample flight activity of adult click beetles, and that these tools may be useful for monitoring activity patterns in spring and dispersal by egglaying females into previously uninfested fields.
Technical Abstract: Japanese beetle traps were used to monitor flight activity of the Pacific coast wireworm, Limonius canus Eschscholtz, in an agricultural field in northern Oregon. Overwintered beetles began appearing in traps in mid-March 2000 and 2001, and were collected in traps until mid- to late-May both years. Most (93%) of the females collected at the beginning of the flight period had been inseminated, which may indicate that mating takes place very soon after beetles emerge from the soil. Sex ratios were heavily male-biased at the beginning of the flight period and were female-biased at the end of the flight period. Cool temperatures in April 2001 caused a delay in timing of the peak catch (relative to timing in 2000) by almost 3 weeks. Counts of over 10 beetles per trap per 7-day sampling interval were obtained during the week of peak catch. Traps were hung at three heights (1.5, 0.9, and 0.3 m above ground). Trap catch decreased with increasing trap height. Yellow traps collected more beetles than traps that had been painted white, which in turn collected more beetles than traps that had been painted red, green, dark blue, or black. Scattered individuals of Selatosomus pruininus (Horn) and Cardiophorus montanus Bland were also collected during the study.