Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 30, 2005
Publication Date: October 2, 2005
Citation: Clement, S.L. 2005. Forecasting pea aphid outbreaks on peas in the u.s. pacific northwest: slam dunk or slim chance? [abstract]. Program and Abstracts Book, 7th International Symposium on Aphids. p. 27-28. Technical Abstract: Pea aphid outbreaks occurred in western Oregon on annual legumes in 1918, with eight more between 1919 and 1942. Additional outbreaks occurred on spring pea in 1934 in the Blue Mountain region of eastern Washington and Oregon and on field pea in 1983, 1990, 1996, and 2005 in the Palouse region of eastern Washington. Mild winters have long been linked to the occurrence of these outbreaks, although analyses of winter temperatures for 23 years (1983-2005) has revealed no consistent association between winter (December, January, February) temperatures and the incidence of pea aphid outbreaks. Beyond ambient temperatures, detailed information about many other factors (winter pea aphid egg survival on host plants; alfalfa cutting cycles; host plant quality; rainfall; prevailing wind speeds and trajectories that influence aphid dispersal to spring peas) is required before attempting to develop a system to forecast pea aphid outbreaks. Given limited human and financial resources and the requirement for data on multiple variables, chances are slim that a reliable forecasting system for pea aphid outbreaks will be developed in the near future. There is no substitute for regular field sampling to detect pea aphid outbreak infestations.