LARVAE OF THE PEA AND BEAN WEEVIL, SITONA-LINEATUS, AND THE YIELD OF FIELD BEANS

In. 16 experiments with field beans at Rothamsted, Woburn and Saxmundham between 1969 and 1976, seed-bed applications to the soil of dieldrin or y-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. lineatus larvae as pests of field beans in Britain has been under-rated. © 1979, Cambridge University Press. All rights reserved.