Published February 1909. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Four sampling techniques were evaluated to estimate clover aphid, Nearctaphis bakeri
(Cowen), abundance in red clover fields in the Willamette Valley. The Berlese funnel method
detected one to four times more aphids than other sampling techniques. Visual assessment
often underestimated the high aphid densities during the flowering and seeding of...
Four key aspects of the relationship between predatory hoverflies and the aphid pest Brevicoryne brassicae L. on broccoli were investigated in the Willamette Valley, Oregon USA: 1) the relationship between aphid density and hoverfly oviposition, 2) the larval voracity of key hoverfly species, 3) the preferences of hoverflies and broccoli...