a1 AFRC Institute of Arable Crops Research, Rothamsted Experiment Station, Harpenden, Herts, AL5 2JQ, UK
a2 Silwood Centre for Pest Management, Imperial College at Silwood Park, Ascot, Berks, SL5 7PY, UK
Metopolophium dirhodum (Walker) is occasionally a pest of cereals in the UK. A simulation model was developed to study its population dynamics and damage potential. The model was initiated by the aphid immigration as measured by 12·2-m suction trap samples and with temperature as the major driving variable. It was validated with field observations from three contrasting years, 1979, 1985 and 1986. The model accurately predicted aphid populations and yield loss in a major outbreak year (1979) but was less accurate when densities were lower (1985 & 1986). Possible reasons for these discrepancies are discussed.
(Received October 25 1988)