Local variation in cereal aphid flight activity in Canterbury

Abstract

Autumnwinter flight activity of aphids vectors of barley and cereal YDV measured in 75 m high suction traps was compared from four sites in Canterbury between 19972003 For weekly trap catches the relationship between traps was usually poor (R²lt;064) except for Rokeby and Courtenay (R²089) These relationships improved (R²gt;075) when combining weekly into monthly seasonal (AprilJuly) and winter (JuneJuly only) values except for the monthly comparisons with Hilton (R²lt;054) In general suction trap catches at Hilton were most dissimilar from other traps Courtenay and Rokeby were the most similar Internet usage in 2003 indicated that users were least interested in the Courtenay trap data This analysis suggests that not all suction traps are needed to provide useful information to cereal farmers However the utility of a particular trap is also influenced by its use for other aphid pest/crop combinations