Overwintering of peach‐potato aphid and severity of attacks in sugar beet in relation to winter and spring temperature

Abstract

Virus yellows (Beta virus 4) is the most important disease in sugar beet (Beta vulgaris) in Denmark. Virus yellows is spread by the peach-potato aphid (Myzuspersicae). The princi a1 source of infestation are clamps where the peach-potato a hids can overwinter anhalocyclical&. Overwintering and abundance are dependent on winter a n f spring temperatures.In the period 1987-89, the abundance of peach-potato aphids was examined every year in 80-101 sugar beet fields. The temperature measurements were recorded daily at local meteorological stations.A regression analysis was used to estimate a model to describe the relationship between YO fields infested with peach-otato aphids, winter temperature and s ring temperature. The model can account for 83 % of tge variance. O n an average the model can Porecast the % fields attacked with a reliability of 0.8. The model allows a forecast to be made in the early spring which can then form the basis for a recommendation on a control strategy.