Ecology of the Dutch elm disease vectors Scolytus laevis and S. scolytus (Coleoptera: Scolytidae) in southern Sweden.
Abstract
Distribution and phenology of the beetles was studied at an infestation centre in a wood dominated by Ulmus glabra in Scania, S. Sweden, in 1983-85 using pheromone-baited sticky traps. Distribution was very concentrated with a low proportion of dispersing beetles. Flight activity occurred from May to Sep., with a first peak in July and a second peak in Aug. in 2 of the years for S. scolytus. The commercially available racemic 4-methyl-3-heptanol was attractive to S. scolytus over a range of release rates (0.3-20 mg/d) but less so for S. laevis. Efficiency of the sticky traps (white cardboard) was similar to or better than that of non-sticky window traps and drainpipe traps with exterior funnels.