Submitted to: Western Orchard Pest and Disease Management Conference
Publication Type: Abstract Only
Publication Acceptance Date: 12/15/1999
Publication Date: 1/5/2000
Citation: Knight, A.L., Marsello, M. 2000. The areawide distribution of Pandemis leafroller among tree fruit crops in the Parker Heights district. Western Orchard Pest and Disease Management Conference. p. 85-86.
Technical Abstract: In the Yakima Valley of Washington the population dynamics of Pandemis pyrusana (PLR) were studied in a 380 acre area of fruit production comprised of apple, pear, cherry, peach/ nectarine, apricot, and plum. Adult moths were trapped using low load (10% standard load) sex-pheromone baited traps and liquid food (fermented molasses) baited traps. Blocks were sampled for overwintering larvae, summer generation larvae, and fruit injury. Overwintering larvae were found in all crops except peach/nectarine, apricot, and prune. The highest percent shoot infestations were found in non-bearing apples. Population densities were similar in apple and cherry and somewhat lower in pear. Levels of fruit injury by PLR were low (< 0.1%) in apples and pears. Blocks with damaged fruit were clumped into two main areas, both of which were in close proximity to blocks of cherry and non-bearing apple with high summer larval densities. Moth catch in sex pheromone and food bait traps did correlate slightly with summer larval densities and fruit injury levels. However, moth catch during second flight showed little correlation to fruit injury.