Damage to beans by larvae of the common bean weevil, Acanthoscelides obtectus

Bean weevils, also known as seed beetles, are members of the beetle subfamily Bruchinae. They are placed in the leaf beetle family Chrysomelidae, though they were historically treated as a separate family. Despite being called "bean weevils", they are not true weevils. The subfamily includes about 1,650 species and are found worldwide.

Bean weevils are generally compact and oval in shape, with small heads somewhat bent under. Sizes range from 1–22 millimetres (0.039–0.866 in) for some tropical species. Colors are usually black or brown, often with mottled patterns. Although their mandibles may be elongated, they do not have the long snouts characteristic of other weevils. A defining characteristic of this subfamily is that the elytra don't quite reach the tip of their abdomens (as seen in the header image).

The Bruchinae are granivores, and typically infest various kinds of seeds or beans (hence their common names), living most of their lives inside a single seed;[citation needed] Host plants tend to be legumes, but species will also be found in Convolvulaceae, Arecaceae, and Malvaceae. The adults deposit eggs on seeds of these plants, then the larvae chew their way into the seed. When ready to pupate, the larvae typically cut an exit hole, then return to their feeding chamber. Due to this, several species are considered pests. The adult weevils have a habit of feigning death and dropping from a plant when disturbed.

Several species are native to Great Britain, but there are also records of several introduced species from stored products in warehouses and dwellings, although these species cannot proliferate outside of heated buildings in that climate.[relevant?]

Genera

This list of genera uses the new classification scheme, treating the bean weevils as a subfamily with six extant tribes, eight or nine subtribes, and one extinct tribe. The former names and ranks for the tribes and subtribes under the old classification, treating the been weevils as a family, are given in parentheses (except for Myanmaropini, which was established only for the new classification).

  • Tribe Amblycerini Bridwell, 1932 (= Subfamily Amblycerinae) Subtribe Amblycerina Bridwell, 1932 (= Tribe Amblycerini) Amblycerus Thunberg, 1815 Subtribe Spermophagina Borowiec, 1987 (= Tribe Spermophagini) Spermophagus Schoenherr, 1833 Zabrotes Horn, 1885
  • Tribe Bruchini Latreille, 1802 (= Subfamily Bruchinae) Subtribe Acanthoscelidina Bridwell, 1946 (= Tribe Acanthoscelidini) Abutiloneus Bridwell, 1946 Acanthoscelides Schilsky, 1905 Algarobius Bridwell, 1946 Althaeus Bridwell, 1946 Bonaerius Bridwell, 1952 Caryedes Hummel, 1827 Cosmobruchus Bridwell, 1931 Ctenocolum Kingsolver & Whitehead, 1974 Dahlibruchus Bridwell, 1931 Gibbobruchus Pic, 1913 Lithraeus Bridwell, 1952 Margaritabruchus Romero & Johnson, 2001 Meibomeus Bridwell, 1946 Megasennius Whitehead & Kingsolver, 1975 Merobruchus Bridwell, 1946 Mimosestes Bridwell, 1946 Neltumius Bridwell, 1946 Neobruchidius Johnson & Romero, 2006 Palpibruchus Borowiec, 1987 Pectinibruchus Kingsolver, 1967 Penthobruchus Kingsolver, 1973 Pseudopachymerina Zacher, 1952 Pygiopachymerus Pic, 1911 Rhipibruchus Bridwell, 1932 Scutobruchus Kingsolver, 1968 Sennius Bridwell, 1946 Spatulobruchus Borowiec, 1987 Stator Bridwell, 1946 Stylantheus Bridwell, 1946 Subtribe Bruchidiina Bridwell, 1946 (= Tribe Bruchidiini) Acanthobruchidius Borowiec, 1980 Borowiecius Anton, 1994 Bruchidius Schilsky, 1905 Callosobruchus Pic, 1902 Conicobruchus Decelle, 1951 Decellebruchus Borowiec, 1987 Horridobruchus Borowiec, 1984 Kingsolverius Borowiec, 1987 Megabruchidius Borowiec, 1984 Palaeoacanthoscelides Borowiec, 1985 Parasulcobruchus Anton, 1999 Pygobruchidius Pic, 1951 Salviabruchus Decelle, 1982 Specularius Bridwell, 1938 Sulcobruchus Chûjô, 1937 Tuberculobruchus Decelle, 1951 Subtribe Bruchina Latreille, 1802 (= Tribe Bruchini) Bruchus Linnaeus, 1767 Subtribe Megacerina Bridwell, 1946 (= Tribe Megacerini) Megacerus Fåhraeus, 1839
  • Tribe Eubaptini Bridwell, 1932 (= Subfamily Eubaptinae) Eubaptus Lacordaire, 1845
  • Tribe Kytorhinini Bridwell, 1832 (= Subfamily Kytorhininae) Kytorhinus Fischer von Waldheim, 1809
  • Tribe Pachymerini Bridwell, 1929 (= Subfamily Pachymerinae) Subtribe Caryedontina Bridwell, 1929 (= Tribe Caryedontini) Aforedon Decelle, 1965 Caryedon Schoenherr, 1823 Caryotrypes Decelle, 1968 Exoctenophorus Decelle, 1968 Mimocaryedon Decelle, 1968 Subtribe Caryopemina Bridwell, 1929 (= Tribe Caryomepini) Caryopemon Jekel, 1855 Diegobruchus Pic, 1913 Protocaryopemon Borowiec, 1987 Subtribe Pachymerina Bridwell, 1929 (= Tribe Pachymerini) Butiobruchus Prevett, 1966 Caryobruchus Bridwell, 1929 Caryoborus Schoenherr, 1833 Pachymerus Thunberg, 1805 †Mesopachymerus Poinar, 2005 Canadian amber, Campanian
  • Tribe Rhaebini Chapuis, 1874 (= Subfamily Rhaebinae) Rhaebus Fischer von Waldheim, 1824
  • Tribe †Myanmaropini Legalov et al., 2020 †Myanmarops Legalov et al., 2020 Burmese amber, Myanmar, Cenomanian

Notes

External links