Weevils are beetles belonging to the superfamily Curculionoidea, known for their elongated snouts. They are usually small – less than 6 mm in length – and herbivorous. Approximately 97,000 species of weevils are known. They belong to several families, with most of them in the family Curculionidae. It also includes bark beetles, which while morphologically dissimilar to other weevils in lacking the distinctive snout, is a subfamily of Curculionidae. Some other beetles, although not closely related, bear the name "weevil", such as the biscuit weevil, which belongs to the family Ptinidae.
The bean weevils or seed beetles are a subfamily (Bruchinae) of beetles, now placed in the family Chrysomelidae, though they have historically been treated as a separate family. They are granivores, and typically infest various kinds of seeds or beans, living most of their lives inside a single seed. The subfamily includes about 1,650 species and are found worldwide.
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.
Caridae is a small Gondwanan family of weevils. They are considered part of the primitive weevil group, because they have straight rather than geniculate (elbowed) antennae. The insertion of the antennae on the rostrum cannot be seen from above. Caridae also lack spiracles on abdominal tergites 6 and 7. The prothorax lacks lateral carinae. It has been suggested that the fossil weevil Eccoptarthrus belongs in this family, which would result in a change in the family name ; this proposal has been rejected by most coleopterists (e.g.)
Belidae is a family of weevils, called belids or primitive weevils because they have straight antennae, unlike the "true weevils" or Curculionidae which have geniculate (elbowed) antennae. They are sometimes known as "cycad weevils", but this properly refers to a few species from the genera Parallocorynus and Rhopalotria.
Brentidae, sometimes known as the primitive weevils, is a cosmopolitan family of primarily xylophagous beetles also known as straight-snouted weevils. The concept of this family has been 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.
Hylobius is a genus of true weevils. Several Hylobius species are major pests of coniferous trees.
Anthribidae is a family of beetles also known as fungus weevils. The antennae are not elbowed, may occasionally be longer than the body and thread-like, and can be the longest of any members of Curculionoidea. As in the Nemonychidae, the labrum appears as a separate segment to the clypeus, and the maxillary palps are long and projecting.
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 autumn, 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.
The palm weevil Rhynchophorus ferrugineus is one of two species of snout beetle known as the red palm weevil, Asian palm weevil or sago palm weevil. The adult beetles are relatively large, ranging between 2 and 4 centimetres long, and are usually a rusty red colour—but many colour variants exist and have often been classified as different species. Weevil larvae can excavate holes in the trunks of palm trees up to 1 metre (3.3 ft) long, thereby weakening and eventually killing the host plant. As a result, the weevil is considered a major pest in palm plantations, including the coconut palm, date palm and oil palm.
Nemonychidae is a small family of weevils, placed within the primitive weevil group because they have straight rather than geniculate (elbowed) antennae. They are often called pine flower weevils. As in the Anthribidae, the labrum appears as a separate segment to the clypeus, and the maxillary palps are long and projecting. Nemonychidae have all ventrites free, while Anthribidae have ventrites 1-4 connate or partially fused. Nemonychidae lack lateral carinae on the pronotum, while these are usually present, though may be short, in Anthribidae.
Hadramphus tuberculatus is a rare weevil endemic to Canterbury in the South Island of New Zealand. It was thought to be extinct in 1922 but was rediscovered in 2004.
Rhinocyllus conicus is a species of true weevil. It is best known as a controversial agent of biological pest control which has been used against noxious thistles in the genera Carduus, Cirsium, Onopordum, and Silybum.
Otiorhynchus is a large genus of weevils in the family Curculionidae. Many species of the genus, particularly the black vine weevil and the strawberry root weevil, are important pests, both as larvae and as adults. Larvae feed on plant roots. Adults are flightless with fused elytra and feed at night on plant foliage. In many species of the genus at least some races are polyploid and parthenogenetic, while the rest of the races and species are diploid and bisexual. Otiorhynchus weevils, particularly O. scaber, have been a popular subject for studies of the evolution of parthenogenesis. The genus is native to the Palearctic region. However, sixteen species were inadvertently introduced to North America and have become widespread there.
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.
Rhynchaenus is a genus of beetles alternatively placed in the subfamilies Rhynchaeninae or in Curculioninae, of family Curculionidae. It previously included the genus Orchestes, but is now restricted to a smaller group of species, all of which occur in Europe, Japan, or North Africa and feed on Asteraceae plants. Reports of its occurrence in North America are erroneous.
Rhynchophorus, or common name palm weevils, is a genus of beetles in the weevil family, Curculionidae. Palm weevils are major pests of various trees in the family Arecaceae throughout the tropics including: coconut, Areca catechu, species of the genus Phoenix, and Metroxylon sagu. Two species are invasive pests outside their native ranges, Rhynchophorus ferrugineus and Rhynchophorus palmarum.
Ceutorhynchus is a genus of true weevils in the tribe Ceutorhynchini. There are at least 400 described species in Ceutorhynchus.
Leiosoma deflexum is a species of weevil native to Europe.
Hybomorphus is a genus of weevil in the family Curculionidae. There is just one species in the genus, the type species, Hybomorphus melanosomus, the Lord Howe Island ground weevil.
