Cryphalus | |
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Cryphalus abietis | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Coleoptera |
Infraorder: | Cucujiformia |
Family: | Curculionidae |
Tribe: | Cryphalini |
Subtribe: | Cryphalina |
Genus: | Cryphalus W.F. Erichson, 1836 |
Synonyms | |
Hypocryphalus Hopkins, 1915 |
Cryphalus is a large genus of tiny bark beetles, subfamily Scolytinae, tribe Cryphalini in the family Curculionidae. The genus is widely distributed. The species feed and breed under the inner bark of trees. They infest mainly recently dead, dying or stressed trees. Some species are regarded as invasive pests, harmful to agriculture or forestry. [1]
The genus Cryphalus can be recognized by a combination of morphological characters mainly on the eyes, the antennae and tarsi. The genus has been revised in 2020 by Johnson et al. and currently includes 253 species. [1] [2] During that revision several genera have been combined with the genus Cryphalus like the genus Hypocryphalus which turned out to be polyphyletic and intermixed with Cryphalus. See that revision for a complete list of synonyms for the genus Cryphalus. [1]
Type species: Bostrichus asperatus Gyllenhal, 1813 [1]
The genus Cryphalus has a world-wide distribution, but the species found in Central and South America are regarded as introduced. [1] The large majority of species have been recorded in eastern Asia and the Pacific. In a checklist published in 2020, 140 species were listed in eastern Asia (including the Philippines), 90 in the Pacific and Australia (including New Guinea), 23 in Africa, 21 in western Asia, 6 each in Europe and North/Central America, and 2 in South America (some species were reported from more than one region). [2]
The adult beetles are tiny, dark brown and range in size from 0.8 to 3 mm. [3] However, adults smaller than 1.2 mm and larger than 2.5 mm are rare. In dorsal view, the head is often hidden under the pronotum, which is large, domed, and with the anterior parts covered by tubercles. Many parts of the cuticle bear hair-like setae. See Wikimedia Commons for additional illustrations.
Species of Cryphalus either infest tree branches or the stems of young host trees, where they colonize the phloem tissue under the bark, feeding on the phloem and cambium. Weakened or stressed host trees are usually preferred. Most species are either monophagous or oligophagous. In Europe, the host trees of most species are conifers. [4] However, in other regions, angiosperms are also commonly infested. [3]
A typical life cycle has been described for Cryphalus piceae which mainly infests fir trees or spruce in central and southern Europe. [4] The adult beetles hibernate in short tunnels formed in healthy trees. They emerge in spring, mate and a monogamous pair forms a nuptial chamber under the bark of weakened or freshly dead branches, where the female lays 5–26 eggs. The larvae construct galleries radiating from the nuptial chamber, where the larvae develop and pupate. The adults emerge starting in April to May. Often there is a second generation in the summer. [4]
Most species of Cryphalus cause only minor damage to their host trees. However, several species are regarded as pests, causing decline of trees like fig (Ficus carica), mango (Mangifera indica) or loquat (Eriobotrya japonica). [3]
Bark beetles are often vectors of plant diseases and have special structures for carrying symbiotic fungi called mycangia. Several species of Cryphalus have been associated with plant pathogenic fungi and are regarded or suspected as being vectors of these pathogens. [5] [6]
The genus Cryphalus includes more than 250 species. The species recorded in more than one countries are listed here, based mainly on the 2020 checklist: [2]
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.
A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the term "bark beetle" refers to the fact that many species feed in the inner bark (phloem) layer of trees, the subfamily also has many species with other lifestyles, including some that bore into wood, feed in fruit and seeds, or tunnel into herbaceous plants. Well-known species are members of the type genus Scolytus, namely the European elm bark beetle S. multistriatus and the large elm bark beetle S. scolytus, which like the American elm bark beetle Hylurgopinus rufipes, transmit Dutch elm disease fungi (Ophiostoma). The mountain pine beetle Dendroctonus ponderosae, southern pine beetle Dendroctonus frontalis, and their near relatives are major pests of conifer forests in North America. A similarly aggressive species in Europe is the spruce ips Ips typographus. A tiny bark beetle, the coffee berry borer, Hypothenemus hampei is a major pest on coffee plantations around the world.
The European spruce bark beetle, is a species of beetle in the weevil subfamily Scolytinae, the bark beetles, and is found from Europe to Asia Minor and some parts of Africa.
Hylastes ater is a species of beetle in the family Curculionidae, the true weevils. It is a bark beetle, a member of the subfamily Scolytinae. Its common name is the black pine bark beetle. It is native to Europe and parts of Asia, including China and Korea. It is known as an introduced species in many other regions, including Australia, New Zealand, the Americas, and South Africa. It is a pest of pines and other trees, and it is widespread in areas where pine trees are cultivated. The species "is an important threat to the biosecurity of all forested countries."
Ips is a genus of beetles in the family Curculionidae, the true weevils. They are bark beetles, members of the subfamily Scolytinae. Species are distributed throughout the Northern Hemisphere. Some are known as introduced species in Australia and Africa. Many species are pests of forest trees, especially pines and spruces. They are known commonly as engraver beetles, ips engraver beetles, and pine engravers.
Scolytini is a tribe of typical bark beetles in the family Curculionidae. There are at least 50 genera and 160 described species in Scolytini.
Hypothenemus is a genus of oriental bark beetles in the family Curculionidae. There are more than 200 described species in Hypothenemus. They are common in tropical and subtropical areas worldwide, and found less often in temperate areas of eastern North America and eastern Asia. The small beetles are typically 0.6 mm to 2.2 mm in length, males smaller than females.
Hylastes is a genus of crenulate bark beetles in the family Curculionidae. There are more than 90 described species in Hylastes.
Dryocoetes is a genus of beetles belonging to the family Curculionidae, in the subfamily Scolytinae.
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.
Euwallacea perbrevis, commonly known as tea shot-hole borer, is a species of weevil native to South and South-East Asia through to Australia, but introduced to Western countries.
Cryphalus dilutus, the spurred bark beetle, is a tropical and subtropical bark beetle which attacks fig and mango trees causing dieback. It belongs to the family Curculionidae, subfamily Scolytinae.
Cryphalus mangiferae, the mango bark beetle, is a tiny tropical bark beetle which attacks mango trees. The species belongs to the family Curculionidae, subfamily Scolytinae. It is often cited as a vector of plant pathogenic fungi infecting mango trees and in some countries like Pakistan it is regarded as a serious threat to mango cultivation.
Cryphalus piceae, the small fir bark beetle, is a tiny bark beetle, about 1.7 mm long that is found in central and southern Europe. It infests mainly fir (Abies) and spruce trees (Picea) and occasionally can cause damage to branches and young trees, including tree death.
Cryphalus saltuarius - Cryphalus asperatus is a small bark beetle, around 1.8 mm long, that infests mainly spruce trees (Picea), less often other conifers. It has been recorded mainly from northern Europe and is occasionally regarded as a secondary pest. However, it attacks primarily weakened and freshly dead branches of its host trees.
Cryphalus abietis is a small bark beetle, around 1.6 mm long, that is widely distributed in Europe. It infests mainly spruce trees (Picea), but also other conifers. Like closely related species, e.g. Cryphalus saltuarius, C. abietis attacks primarily weakened and freshly dead branches of its host trees, and usually does not kill trees.
Euwallacea is a genus of typical bark beetles in the family Curculionidae. They are commonly known as Ambrosia beetles, as all species are symbiotic with Ambrosia fungi. Originally from Asia or Wallacea, they are now found worldwide. Many species are pests, causing damage to, or the death of, tree species valued for their fruit or timber.
Cryphalus dorsalis is a small bark beetle, 1.60–1.90 mm long and found in southern parts of Asia with a distribution range from India in the west to Java (Indonesia), the Philippines and southern China in the east. Little information is available on its biology, even on its host plants. In a detailed re-description of the species based on light trap material and specimens without host plant records, Johnson et al. (2020) mentioned that fir (Abies) has been cited as a host plant in one publication which recorded it from Hainan Island (China) where Abies does not grow.
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: CS1 maint: DOI inactive as of April 2024 (link)