Tribe Prionini Latreille, 1802

The tribe Prionini is composed of 50 genera and 212 species (Tavakilian & Chevillotte 2018). Immature stages of 10 species included in five genera are known. Larvae of one undetermined species of Derobrachus Audinet- Serville, 1832 from the USA, and larvae and pupae of Orthosoma brunneum (Forster, 1771) both described by Craighead (1915); larvae of Prionacalus atys White, 1850, described by Duffy (1960); larvae of five species of Prionus Geoffroy, 1762, described by Craighead (1915): Prionus sp. (from USA), P. californicus Motschulsky, 1845, P. imbricornis (Linnaeus, 1767), P. laticollis (Drury, 1773), and P. pocularis Dalman, 1817; larvae and pupae of P. coriarius (Linnaeus, 1758) described by Duffy (1960); larvae of Psalidognathus modestus Fries, 1833 described by Lameere (1885).

Based on the descriptions of the species above, the larvae of Prionini are characterized by having: epistomal margin projected above clypeal base and with additional carina above epistoma; upper boundary varying from straight to slightly bilobed; lower boundary produced over clypeus forming lobes (size and number variable), and paramedian lobe present or absent; antennae with three antennomeres ( Derobrachus sp., Prionus coriarius); or two antennomeres ( Prionacalus atys); stemmata absent in Prionus spp., four pairs (three subcontiguous) in Prionacalus atys and three pairs in Derobrachus sp. and Orthosoma brunneum; abdomen with ambulatory ampullae dorsal and ventral; ampullae grooved and without microspines; segment IX trilobed.

The pupa of only two species, Orthosoma brunneum and Prionus coriarius, are known. Based on its descriptions, the pupae of Prionini are characterized by having the following: head almost concealed by pronotum, glabrous or with asperites; pronotum with two or three pairs of small lateral tubercles; abdomen with tergites rugose with scattered minute papillae or microspines; gin-traps present in O. brunneum, a pair on tergites III, II–III, III–IV, IV–V, V–VI and VI–VII (two first and last less visible); functional spiracles on segments I–VI; tergite IX with two laterodorsal, chitinous, dentate flanges in O. brunneum and paramedian elongate, fleshy protuberances in P. coriarius .