Colonization and spatiotemporal distribution of bruchid pests in lentil and faba bean fields

Lentils (Lens culinaris Medikus, 1787) and faba beans (Vicia faba Linnaeus, 1753) are important crops in France facing threats from Bruchus spp. We analyzed 59 lentil and 45 faba bean fields across four French regions over three growing seasons (2019-2020 to 2021-2022). We investigated the diversity, colonization patterns and spatiotemporal distribution of bruchids at different crop phenological stages and distances from field edges.

Bruchus rufimanus Boheman, 1833 and Bruchus signaticornis Gyllenhal, 1833 were the only species emerging from faba beans (97.8%) and lentils (99.5%), respectively. B. rufimanus colonization was concentrated during pod development, maintaining a balanced male-female ratio throughout. B. signaticornis exhibited a colonization period of ≈1 month, with a gradual increase in female proportion over time. The spatial distribution of bruchids and damage were relatively uniform within fields, indicating strong dispersal capabilities. A significant positive correlation, with a high degree of dispersion, was identified between female abundance and bruchid-damaged grains.

We confirmed that B. rufimanus and B. signaticornis were the only species damaging faba beans and lentils in France, respectively. The homogeneous spatial distribution suggests a strong dispersal ability of bruchids. The high degree of dispersion in the relationship between female abundance and bruchid-damaged grains highlights the importance of regulatory factors influencing larval and egg survival. These results, together with the presence of B. signaticornis in faba beans, emphasize the need for species-specific, phenology-based and spatially informed integrated pest management strategies, to mitigate the impact of bruchids and reduce reliance on chemical in their control. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.