THE USE OF THE LAMB DAILY WEATHER TYPES AND THE INDEXES OF PROGRESSIVENESS, SOUTHERLINESS AND CYCLONICITY TO INVESTIGATE THE AUTUMN MIGRATION OF RHOPALOSIPHUM-PADI

1. The numbers of Rhopalosiphum padi (L.) sampled using UK 12.2 m suct ion traps during the autumn were related to weather data from the prec eding year using multiple regression and correspondence analysis. 2. T he multiple regression approach using data from Ayr, Scotland, 1976-89 , resulted in models that produced good predictions in 10 of the 14 ye ars when tested with data from Belfast, Northern Ireland. 3. The corre spondence analysis (TWINSPAN) approach using data from 1971-90, which grouped years with similar autumn samples of R. padi at six UK suction trap sites, showed associations with temperature in the preceding win ter and rainfall in the preceding summer. This was achieved using the Lamb daily weather types and the indices of progressiveness, southerli ness and cyclonicity.