Myzus persicae

On Prunus persica, inspect for curled leaves, in which colonies develop in early spring.
Monitoring is important in field crops, but M. persicae transmits viruses of crops such as sugar beet and potato at low densities, and is therefore difficult to detect on the crop before the damage is done. Suction and yellow traps are the most efficient way to detect first migration of winged aphids into the crop. Networks of suction traps have been developed to monitor migrating aphids, for example, the Rothamsted Insect Survey in the UK and AGRAPHID in France (Hulle et al., 1987), as part of the 'Euraphid' forecasting system in European Union countries. Much effort has been expended on developing forecasting methods, for example for sugarbeet (Harrington et al., 1989). Appropriate applications of insecticides are often based on monitoring data. Insecticide application in sugar beet against M. persicae is only necessary when aphids are carrying yellows viruses. Vertical nets placed downwind of fields of infected potato plants can be used to quantify the proportion of M. persicae carrying virus (diagnosed by use of ELISA;see Diagnosis).