The Biology and Ecology of Bruchus rufimanus, the bean seed beetle

Bruchus rufimanus (bean seed beetle) is an economically important pest of Vicia faba throughout Europe and became established as a serious pest in the UK in the early 1990’s. Female B. rufimanus oviposit onto developing pods, and hatching larvae bore through the base of the egg and the V. faba pod walls. Larvae feed and pupate in the seed and adult B. rufimanus emerge at crop senescence, leaving a round hole, approximately two to three millimetres in diameter in the V. faba grain. Damage to grain quality affects the end use, and major existing markets for V. faba grown in the UK include those for UK animal feed, seed and for export for human consumption. Grain traders exercise strict quality requirements for freedom from staining and pest damage and for exported grain intended for human consumption, damage caused by B. rufimanus must not exceed 2% in V. faba produced in the UK.

Management of B. rufimanus has proved difficult and the choice of insecticides approved in V. faba in the UK is currently limited. The principal objective of the research was to improve management of B. rufimanus in V. faba and in particular to:

Investigate the distribution of B. rufimanus throughout the UK to inform V. faba growers of regional risk;
Improve knowledge of the factors influencing emergence of B. rufimanus from over-winter habitats and termination of reproductive diapause;
Provide a strategy for field control whilst reducing impact on beneficial organisms;
Improve knowledge of the conditions required for oviposition to commence;
Provide alternative strategies to manage B. rufimanus, including the use of cultural and rotational techniques;
Improve knowledge of the factors influencing the selection of or preference for over-wintering habitats