Abstract
To simulate the infestation of Barley leaf-miner, Agromyza albipennis Meigen, apical halves of upper 2 leaves of wheat were artificially defoliated for 3 years at two localities in Hokkaido. The result showed that the yield losses were 20% and 13% at maximum for spring-and winter-wheat respectively, when either one of upper 2 leaves was cut off. The economic injury levels based on yield loss and spray costwere estimated at 12% and 16% damaged leaves in upper 2 leaves of spring-and winter-wheat, respectively.
