Beetles are insects that form the order Coleoptera, in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 described species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal species; new species are discovered frequently, with estimates suggesting that there are between 0.9 and 2.1 million total species. Found in almost every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles often feed on plants and fungi, break down animal and plant debris, and eat other invertebrates. Some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae eat aphids, scale insects, thrips, and other plant-sucking insects that damage crops. Some others also have unusual characteristics, such as fireflies, which use a light-emitting organ for mating and communication purposes.
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.
Ambrosia beetles are beetles of the weevil subfamilies Scolytinae and Platypodinae, which live in nutritional symbiosis with ambrosia fungi. The beetles excavate tunnels in dead or stressed trees into which they introduce fungal gardens, their sole source of nutrition. After landing on a suitable tree, an ambrosia beetle excavates a tunnel in which it releases its fungal symbiont. The fungus penetrates the plant's xylem tissue, extracts nutrients from it, and concentrates the nutrients on and near the surface of the beetle gallery. Ambrosia fungi are typically poor wood degraders, and instead utilize less demanding nutrients. Symbiotic fungi produce and detoxify ethanol, which is an attractant for ambrosia beetles and likely prevents growth of antagonistic pathogens and selects for other beneficial symbionts. The majority of ambrosia beetles colonize xylem of recently dead trees, but some colonize stressed trees that are still alive, and a few species attack healthy trees. Species differ in their preference for different parts of trees, different stages of deterioration, and in the shape of their tunnels ("galleries"). However, the majority of ambrosia beetles are not specialized to any taxonomic group of hosts, unlike most phytophagous organisms including the closely related bark beetles. One species of ambrosia beetle, Austroplatypus incompertus exhibits eusociality, one of the few organisms outside of Hymenoptera and Isoptera to do so.
Cucujoidea is a superfamily of beetles. This group formerly included all of the families now included in the superfamily Coccinelloidea. They include some fungus beetles and a diversity of lineages of "bark beetles" unrelated to the "true" bark beetles (Scolytinae), which are weevils.
Beauveria bassiana is a fungus that grows naturally in soils throughout the world and acts as a parasite on various arthropod species, causing white muscardine disease; it thus belongs to the group of entomopathogenic fungi. It is used as a biological insecticide to control a number of pests, including termites, thrips, whiteflies, aphids and various beetles. Its use in the control of bed bugs and malaria-transmitting mosquitos is under investigation.
Ant–fungus mutualism is a symbiosis seen between certain ant and fungal species, in which ants actively cultivate fungus much like humans farm crops as a food source. There is only evidence of two instances in which this form of agriculture evolved in ants resulting in a dependence on fungi for food. These instances were the attine ants and some ants that are part of the Megalomyrmex genus. In some species, the ants and fungi are dependent on each other for survival. This type of codependency is prevalent among herbivores who rely on plant material for nutrition. The fungus’ ability to convert the plant material into a food source accessible to their host makes them the ideal partner. The leafcutter ant is a well-known example of this symbiosis. Leafcutter ants species can be found in southern South America up to the United States. However, ants are not the only ground-dwelling arthropods which have developed symbioses with fungi. A similar mutualism with fungi is also noted in termites within the subfamily Macrotermitinae which are widely distributed throughout the Old World tropics with the highest diversity in Africa.
The term mycangium is used in biology for special structures on the body of an animal that are adapted for the transport of symbiotic fungi. This is seen in many xylophagous insects, which apparently derive much of their nutrition from the digestion of various fungi that are growing amidst the wood fibers. In some cases, as in ambrosia beetles, the fungi are the sole food, and the excavations in the wood are simply to make a suitable microenvironment for the fungus to grow. In other cases, wood tissue is the main food, and fungi weaken the defense response from the host plant.
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.
The Attelabidae is a widespread family of weevils. They are among the primitive weevils, because of their straight antennae, which are inserted near the base of the rostrum. The prothorax is much narrower than the base of the elytra on the abdomen. Attelabidae and the related family Rhynchitidae are known commonly as the leaf-rolling weevils. Rhynchitidae may be treated as subfamily Rhynchitinae of the Attelabidae.
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.
Fungivory or mycophagy is the process of organisms consuming fungi. Many different organisms have been recorded to gain their energy from consuming fungi, including birds, mammals, insects, plants, amoebas, gastropods, nematodes, bacteria and other fungi. Some of these, which only eat fungi, are called fungivores whereas others eat fungi as only part of their diet, being omnivores.
Austroplatypus incompertus, a type of ambrosia beetle, is endemic to Australia. They are found in mesic forests, and subtropical and tropical ecosystems along the east coast of Australia. There are many unique characteristics attributable to the A. incompertus, like their gallery excavation in several Eucalyptus species, their obligate eusocial behavior, their relationship with fungi, and their unique sexual dimorphism. These beetles are one of the only insects that display obligate eusocial behavior. Additionally, their sexually dimorphic traits are of interest, since body size is reversed with males having smaller torsos than female A. incompertus beetles.
Apoderus coryli, the hazel-leaf roller weevil, is a species of leaf-rolling beetles belonging to the family Attelabidae subfamily Attelabinae. Because of the trunk-like elongated head, it is often mistakenly attributed to the weevil family Curculionidae.
Attelabinae is a subfamily of leaf-rolling weevils in the beetle family Attelabidae. There are at least 20 genera and more than 690 described species in Attelabinae.
Deporaus marginatus, commonly known as the mango leaf-cutting weevil, is a species of leaf weevil in the beetle family Attelabidae. It is a light tan colour with black elytra, and is found in tropical Asia where it is a pest of mango.
Attelabus nitens is a species of leaf-rolling weevil in the beetle family Attelabidae, found in Europe. Known as the oak leaf-roller, it is so named because the female has a habit of rolling itself in oak leaves after laying an egg.
Hoherius meinertzhageni, the ribbonwood fungus weevil, is an endemic New Zealand beetle that has been recorded feeding on the ribbonwood species Plagianthus regius and Plagianthus divaricatus and the mountain lacebark, Hoheria glabrata.
Euwallacea interjectus is a species of ambrosia beetle in the species complex called Euwallacea fornicatus. It is native to Asia but has been introduced to the Western hemisphere over the last century.
Ambrosiella roeperi is the fungal symbiont of the granulate ambrosia beetle, Xylosandrus crassiusculus, facilitating this insect’s capacity to accumulate on and damage a diverse array of woody plants from around the world. It is one of several important nutritional partners derived from order Microascales that sustain and are transported by xylomycetophagous scolytine beetles.
Euwallacea validus is a species of Euwallacea beetle native to Asia. The beetle species was discovered in Long Island, New York in 1975. Like other Euwallacea species beetles, E. validus is known for its mutualistic symbiotic relationship with fungi, acting as a vector for Fusarium oligoseptatum and Raffaelea subfusca, often using Tree of Heaven as a preferred host. Out of the five confirmed species of Euwallacea spp. in the United States, E. validus is the most widespread and longest established, yet much about their second fungal partner, Raffaelea subfusca, is not known.
