Diurnal Fluctuations in Nonpersistent Virus Transmission hy Aphids1

Abstract
Transmission of a strain of cabbage mosaic virus (= turnip mosaic or cabbage virus A) by Myzus persicae (Sulzer) or Brevicoryne brassicae (L.) was less after 12 hours than after 24 hours of acquisition access time if the experiment was begun in the morning. The reverse was true if the experiment was begun in the evening. The diurnal fluctuation in transmission efficiency probably was due to the tendency of the aphids to change feeding sites in the morning.