They include the bark beetles as subfamily Scolytinae, which are modified in shape in accordance with their wood-boring lifestyle. They do not much resemble other weevils, so they were traditionally considered a distinct family, Scolytidae. The family also includes the ambrosia beetles, of which the present-day subfamily Platypodinae was formerly considered the distinct family Platypodidae.
|True weevils and bark beetles|
|Some 20 subfamilies (but see text)|
They are recognized by their distinctive long snouts and geniculate antennae with small clubs; beyond that, curculionids have considerable diversity of form and size, with adult lengths ranging from 1 to 40 mm (0.04 to 1.57 in).
Weevils are almost entirely plant feeders, and most species are associated with a narrow range of hosts, in many cases only living on a single species. With so many species to classify and over 400 genera, the taxonomy of this family is quite complicated, and authors disagree on the number and placement of various subfamilies, tribes, and subtribes.
The phylogeny of the group is complex; with so many species, a spirited debate exists about the relationships between subfamilies and genera. A 1997 analysis attempted to construct a phylogeny based mainly on larval characteristics.
Recent work on the phylogenetic relationships in weevils mentions the two subfamily groups Adelognatha (short-nosed weevils, subfamily Entiminae) and Phanerognatha (long-nosed weevils, subfamilies of Curculionidae other than Entiminae) for the species of Curculionidae.
Almost two dozen subfamilies are recognized by some authors even when merging those that are certainly invalid. Others, however, recognize a lesser number – the only subfamilies that are almost universally considered valid are the Baridinae, Cossoninae, Curculioninae, Cyclominae, Entiminae, Molytinae, Platypodinae, and Scolytinae. The various proposed taxonomic schemes typically recognize as many additional subfamilies again, but little agreement is seen between authorities about which. In particular, the delimitation of the Molytinae has proven difficult.
The subfamilies considered valid by at least some authors today:
Other University web pages on economically important curculids:
Anthonomus is a genus of weevils. This genus includes major agricultural pests such as the boll weevil, strawberry blossom weevil, and pepper weevil, as well as promising biological pest control agents such as Anthonomus santacruzi.Baridinae
Baridinae is a subfamily of true weevils (Curculionidae). It was established by Carl Johan Schönherr in 1836. Some 4,300 species in 550 genera are placed here, most of which occur in the New World. A few are economically significant pests, while others are in turn used for biocontrol of invasive plant pests. This subfamily also contains a few endangered species.Belidae
Belidae is a family of weevils, called belids or primitive weevils because they have straight antennae, unlike the "true weevils" or Curculionidae which have elbowed antennae. They are sometimes known as "cycad weevils", but this properly refers to a few species from the genera Parallocorynus and Rhopalotria.Brentidae
Brentidae is a cosmopolitan family of primarily xylophagous beetles also known as straight-snouted weevils. The concept of this family has been recently expanded with the inclusion of three groups formerly placed in the Curculionidae; the subfamilies Apioninae, Cyladinae, and Nanophyinae, as well as the Ithycerinae, previously considered a separate family. They are most diverse in the tropics, but occur throughout the temperate regions of the world. They are among the families of weevils that have non-elbowed antennae, and tend to be elongate and flattened, though there are numerous exceptions.
The subfamilial classification of the family has been reorganized by several different authors within the last 20 years, and is not yet stable; the most recent, and conservative, classification (Oberprieler et al., 2007) accepts only 6 subfamilies, with many familiar subfamilial taxa (e.g., Antliarhininae, Cyladinae, Cyphagoginae, Myrmacicelinae and Trachelizinae) now relegated to the corresponding tribal groups, Antliarhinini, Cyladini, Cyphagogini, Myrmacicelini and Trachelizini, primarily within the subfamily Brentinae.Ceutorhynchus
Ceutorhynchus is a genus of true weevils in the tribe Ceutorhynchini. There are at least 400 described species in Ceutorhynchus.Ceutorhynchus succinus Legalov, 2013 is a species from the Eocene of Europe found in Baltic amber.Conotrachelus
Conotrachelus is a genus of true weevils in the family Curculionidae. It is a very large genus with well over 1,000 species, several of which are pests of fruit crops.Cryptorhynchinae
The Cryptorhynchinae is a large subfamily of weevils (Curculionidae), with some 6000 species. They are found in most zoogeographic regions although they are most diverse in the Neotropics, Australia and Oceania.
They are distinguished by having their rostrum (snout) backwardly directed between their fore coxae in repose, and fitting within a protective channel that usually ends in a cup-like structure on the mesoventrite (ventral mid thoracic segment). The ends of the tibiae also bear an uncus (small hook-like extensions), a character they share with many other groups of Curculionidae that use woody plants for oviposition. They are merged into the Molytinae in some treatments, but a recent molecular study shows that Cryptorhynchinae sensu stricto are monophyletic and best kept as an independent subfamily.Some species of Cryptorhynchinae are considered agricultural pests, such as the mango seed weevil Sternochetus mangiferae, but the great majority of species live in primary forests, often on deadwood and are threatened by habitat loss. In Europe, the flightless genus Acalles is most diverse, and restricted to woodlands of long-lasting habitat continuityCurculio
Curculio is a genus of weevils belonging the family Curculionidae and subfamily Curculioninae. Members of the genus are commonly referred to as acorn weevils or nut weevils as they infest the seeds of trees such as oaks and hickories. The adult female weevil bores a tiny hole in the immature nut to lay her eggs, which then hatch into legless grubs. In the fall, the grubs bore holes through the shells from the inside to emerge into the soil where they may live for a year or two before maturing into adults.Curculioninae
The beetle subfamily Curculioninae is part of the weevil family Curculionidae. It contains over 23,500 described species in 2,200 genera, and is therefore the largest weevil subfamily. Given that the beetle order (Coleoptera) contains about one-quarter of all known organisms, the Curculioninae represent one of the – if not the – most successful radiations of terrestrial Metazoa.Many weevils of this group are commonly known as flower weevils or acorn and nut weevils, after a food commonly eaten by Curculioninae larvae and imagines — the reproductive organs of plants.Dorytomus
Dorytomus is a genus of weevils belonging the family Curculionidae and subfamily Curculioninae. It was first described by the German entomologist, Ernst Friedrich Germar in 1817.Dryophthorinae
Dryophthorinae is a weevil subfamily within the family Curculionidae. While it is not universally accepted as distinct from other curculionid subfamilies, at least one major recent revision elevated it to family rank, as DryophthoridaeEntiminae
The Entiminae are a large subfamily in the weevil family Curculionidae, containing most of the short-nosed weevils, including such genera as Otiorhynchus, Phyllobius, and Sitona. Some of these weevils are notorious pests of major economic importance.Laemophloeidae
Laemophloeidae, "lined flat bark beetles," is a family in the superfamily Cucujoidea characterized by predominantly dorso-ventrally compressed bodies, head and pronotal discs bordered by ridges or grooves, and inverted male genitalia. Size range of adults is 1–5 mm (0.04–0.2 in) in length. Currently, it contains 40 genera and about 450 species, and is represented on all continents except Antarctica; species richness is greatest in the tropics.
Historically, Laemophloeidae was treated as a subfamily of Cucujidae, but starting in the middle of the 20th century, most of what had been treated as subfamilies of the Cucujidae were considered to be families.
Most laemophloeids, adults and larvae, are found under bark of dead trees, where they apparently are primarily fungivores, although some genera with adults having subcylindrical bodies (e.g., Leptophloeus, Dysmerus) occur in the galleries of bark beetles (Curculionidae: Scolytinae), upon which they may feed. A few genera, but most particularly Cryptolestes, contain some species that are pests of stored grain products. The most important of these are C. ferrugineus (Stephens), C. pusillus (Schönherr), and C. turcicus (Grouvelle).Several genera exhibit unusual modifications to male antennae (especially Cryptolestes, Dysmerus, and Microbrontes), with the scape expanded into hook-like or blade-like structures Several other genera (Rhinomalus, Rhinophloeus, and Metaxyphloeus) related to Laemophloeus are atypical in that the adults are rostrate to varying degrees Photographs of most world genera are available at, and most North American species are pictured at,Rhynchophorus
Rhynchophorus is a genus of beetles in the weevil family, Curculionidae. Palm weevils of the genus Rhynchophorus are major pests of coconut palms throughout the tropics.Sitona
Sitona is a large genus of weevils in the family Curculionidae native to the Nearctic and Palaearctic regions. Over 100 species have been described. Sitona is easily distinguished from related genera by flat, recumbent scales on the mandibles, by the absence of an oval scar on the mandibles, by short and broad rostrum with a deep, longitudinal, median groove, and by dense scales on the body.Sitona specialize on legumes, plants of the family Fabaceae. The larvae eat the root nodules and the adults eat the leaves. Several species of Sitona are important agricultural pests of legumes, especially in its native regions and introduced populations in South Africa, Australia and New Zealand.Species include:
Sitona discoideus Gyllenhal
Sitona fairmairei Allard, 1869
Sitona lepidus Gyllenhal – clover root weevil
Sitona lineatus – pea leaf weevil
Smicronyx is a genus of snout and bark beetles in the family Curculionidae. There are at least 70 described species in Smicronyx.Tropiphorini
Tropiphorini is a weevil tribe in the subfamily Entiminae.Weevil
Weevils are certain beetles, namely the ones belonging to the superfamily Curculionoidea. They are usually small, less than 6 mm (0.24 in), and herbivorous. About 97,000 species of weevils are known. They belong to several families, with most of them in the family Curculionidae (the true weevils). Some other beetles, although not closely related, bear the name "weevil", such as the biscuit weevil (Stegobium paniceum), which belongs to the family Ptinidae.
Many weevils are considered pests because of their ability to damage and kill crops. The grain or wheat weevil (Sitophilus granarius) damages stored grain. The boll weevil (Anthonomus grandis) attacks cotton crops; it lays its eggs inside cotton balls and the larvae eat their way out. Other weevils are used for biological control of invasive plants.
Some weevils have the ability to fly, such as the rice weevil.One species of weevil, Austroplatypus incompertus, exhibits eusociality, one of the few insects outside the Hymenoptera and the Isoptera to do so.