Larvae of the pea and bean weevil, Sitona lineatus, and the yield of field beans

Abstract

SummaryIn 16 experiments with field beans at Rothamsted, Woburn and Saxmundham between 1969 and 1976, seed-bed applications to the soil of dieldrin or γ-HCH were used to control subsequent infestations of the roots by larvae of Sitona lineatus. Rates of between 1·12 and 4·48 kg a.i./ha were used. Larval populations on untreated plots plots were variable, but 70–80% control was usually given by rates of 2·24–4·48 kg a.i./ha. Insecticides nearly always increased yields, the mean increase for all treatments being 0·15 t/ha, but a maximum yield response of over 0·5t/ha was achieved. It is suggested that the importance of S. lineatua larvae as pests of field beans in Britain has been under-rated.