Effects of faba bean (Vicia faba) varieties on the development of Bruchus rufimanus

Abstract

The development of Bruchus rufimanus was assessed in randomised field trials from 2005 to 2007 with eight faba bean genotypes (SU 5/13, SU-BT, Mistral, Merkur, Stabil Merlin, Melodie, Divine). Significant differences, reproducible between the years, were found between the faba bean lines. The varieties most attractive to B. rufimanus ovipositing females were SU-BT and Divine. Merkur showed a certain level of non-preference. The highest mortality rates of eggs and first instar larvae in pod valve tissues were recorded in Merkur (34–45%) and Divine (51–55%). The highest mortality rates of larvae and pupae during their development in seeds (effect of seed coat and cotyledon tissues) were recorded in Merkur (87–90%) and Melodie (87–99%). Parasitation by Triaspis thoracicus contributed to this mortality. The highest levels of B. rufimanus parasitation were found in SU-BT (32–35%), the lowest in Melodie (3–9%). The total reduction in Bruchus rufimanus individuals during their development was relatively high in all varieties, ranging from 72% to 99%.