Last-instar larvae of Bagous elegans (F.), Bagous aliciae Cmoluch, and Bagous lutulosus (Gyllenhal), and the pupa of B. elegans, are described and illustrated for the first time. Biology of these species is analyzed in association with larval morphology and feeding habits. Overall larval and pupal morphological diagnoses of the genus Bagous are updated.

Abbreviations: Morphology: AbI—IX, subsequent abdominal segments (Roman numerals); als_n, anterolateral setae; ams_n, anteromedial setae; as_n, apical setae; at, antenna; BH, body height; BL, body length; BW, body width; cl, clypeus; cls_n, clypeal setae; d_n, dorsal setae; des_n, dorsal epicranial setae; dms_n, dorsal setae of the mala; dpls_n, dorsopleurolateral setae; ds_n, discal setae (of pronotum); fes_n, femoral setae; fs_n, frontal setae; HW, head width; HL, head length; L2, L3, larval instars; les_n, lateral epicranial setae; ligs_n, ligular setae; lpa, labial palp; lr, labral rods; lrm, labrum; lrms_n, labral setae; ls_n, lateral setae; ma, mala; mds_n, dorsal setae of mandible; mes_n, median setae; mpa, maxillary palp; msts_n, mesosternal setae; os_n, orbital setae; pas_n, postantennal setae; pc, pseudocerci; pda_n, pedal setae; pds_n, postdorsal setae; pes_n, postepicranial setae; pfs_n, palpiferal setae; plb, praelabium; plbs_n, praelabial setae; pls_n, posterolateral setae; prns_n, pronotal setae; prs_n, prodorsal setae; pslb, postlabium; pslbs_n, postlabial setae; rs, rostral setae; sos_n, superorbital setae; st, stemmata; stp, stipes; stps, stipal setae; sts_n, sternal setae; ThI—III, subsequent thoracic segments; vms_n, ventral setae of the mala; vpls_n, ventropleural setae; vs_n, vertical setae (of the vertex). Collectors & depositories: MNHW, Museum of Natural History, University of Wrocław; MW, Marek Wanat; RG, Rafał Gosik.