Clover Leaf Weevil

The clover leaf weevil (Brachypera zoilus) is a weevil in the family Curculionidae, order Coleoptera, feeding primarily on leguminous plants, especially clovers (Trifolium species) and alfalfa (Medicago sativa). Adults and larvae both feed on the host plant: adults notch leaf margins while larvae, which live in the soil, feed on root nodules and roots. Leaf notching by adults causes characteristic C-shaped or U-shaped damage visible on clover leaflets, facilitating field identification of infestations. Larval feeding on nitrogen-fixing root nodules can significantly reduce the nitrogen-fixing capacity of host plants, impairing soil fertility and forage productivity in agricultural contexts. B. zoilus is broadly distributed across the temperate Northern Hemisphere, occurring in Europe including Denmark, Norway, and Sweden, and in North America including Canada and the United States, where it was inadvertently introduced. The species inhabits meadows, pastures, alfalfa and clover fields, and various grassland habitats wherever its leguminous host plants are present. Adults overwinter in leaf litter and soil, becoming active in spring with the emergence of host plant growth. B. zoilus is classified as Least Concern on the IUCN Red List. While it can cause economic damage to clover and alfalfa crops, it rarely reaches levels requiring intensive control measures, partly because natural enemies including parasitoid wasps help regulate populations. The species completes one generation per year in most of its range.