Clover Seed Weevil

Protapion assimile is a small apionid weevil in the family Brentidae, subfamily Apioninae, order Coleoptera, known by the shared common name clover seed weevil alongside its congener P. apricans and the unrelated Tychius picirostris. P. assimile is distinguished from P. apricans principally by its host plant preference: while P. apricans predominantly infests red clover (Trifolium pratense), P. assimile shows preference for white clover (Trifolium repens) and alsike clover (Trifolium hybridum), an ecological distinction that reduces direct interspecific competition between these closely related species. Females lay eggs in developing flower heads and seed pods of their respective host plants, and larvae consume developing seeds within the flower head. Adults feed on clover foliage and stems. P. assimile is distributed across Europe and is recorded from Norway and Sweden, inhabiting meadows, pastures, roadsides, and agricultural grasslands where white and alsike clover are present. The species is classified as Least Concern on the IUCN Red List, with populations considered stable across its range. P. assimile can be separated from P. apricans by differences in elytral striation depth, rostrum proportions, and tibial structure, though the two species are frequently confused in field identification due to their similar size and coloration. Both species can cause localized damage to clover seed crops but rarely reach pest status in mixed-clover agricultural systems.