| European spruce bark beetle | |
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Infraorder: | Cucujiformia |
| Family: | Curculionidae |
| Genus: | Ips |
| Species: | I. typographus |
| Binomial name | |
| Ips typographus | |
The European spruce bark beetle (Ips typographus), 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.
Adults are usually 4.0–5.5 millimetres (0.16–0.22 in) long, cylindrical and robust, black or brownish-black. Elytral declivity is slightly shiny, with four teeth on each margin side. The third tooth is the biggest and club like on its top. The egg is yellowish-white. The larva is white and legless. The pupa is also white.
Bark beetles are so named because they reproduce in the inner bark, living and dead phloem tissues, of trees. [1] Adult beetles hibernate in forest litter and host trees when environmental conditions are not favorable for reproduction. When conditions are right, they travel up to half a mile in search of a vulnerable host. Once the host is located, the adult burrows through the weakened bark in order to build tunnels where they can mate and lay eggs. They release pheromones to attract more individuals to the host tree. Two to five weeks after contamination, they may migrate to another host and repeat the process. [2] Once the larvae hatch, they feed and pupate under the bark. Up to three generations are produced per year.
Bark beetles communicate with one another using semiochemicals, compounds or mixtures that carry messages. [3] Some electrophysiological and behavioral statistics show that bark beetles can not only sense olfactory signals directly from other bark beetles, but also some compounds from trees.
It is also possible that beetles are attracted to the pheromone ipslure. They are also thought to be attracted to ethanol, one of the byproducts of microbial growth in dead woody tissues. [1]
Bark beetles can form a symbiotic relationship with certain Ophiostomatales fungi. These phloem-feeding bark beetles use phloem-infesting fungi as an addition to their diet.
European bark beetles have the ability to spread quickly over large areas. Some scientists hypothesize that long-distance movements originating from the Iberian Peninsula may have contributed to their invasion of northern Norway spruce forests. [4] Movements like this can happen when various environmental factors such as severe storms, drought, or mass fungal infections damage or kill host trees. Trees in the genera Picea (spruce), Abies (fir), Pinus (pine), and Larix (larch) are the bark beetles' trees of choice. The most recent spruce bark beetle invasive outbreaks are found mainly in fallen, diseased or damaged Norway spruce. [5] Healthy trees use defenses by producing resin or latex, which might contain several insecticidal and fungicidal compounds that kill or injure attacking insects. [6] However, under outbreak conditions, the beetles can overwhelm the tree's defenses. [6]
Though it specializes on Norway spruce, it is not found throughout the tree's range. It may not be able to persist in the northernmost spruce forests due to inadequate climatic oscillations. [7] Other researchers argue that the beetle populations that have evolved in such regions have an active, directed host searching ability and are not equipped for long-range dispersal. [7]
The European spruce bark beetle has a significant impact on both the ecological and economic environment of Norway spruce forests. Together with storm events, bark beetle outbreaks are thought by some to be one of the most important natural disturbances in this region. [6] Some scientists consider this beetle to be a keystone species, [2] in part because it has an unusually high number of relationships with other organisms in the community and because it changes its environment so drastically. [8]
Outbreak species, in general, assist in the renewal of the forest. Also, they further the evolution of stronger, more resistant trees by instigating a range of adaptations to ward off their attacks.
The bark beetles of the Norway spruce forests are associated with various types of fungi, who each have different basic ecological roles. Several fungal pathogens can be transmitted to spruces by the beetles. One of the most damaging is a species of blue stain fungus, Ophiostoma polonicum , which can kill healthy trees by hindering the upward flow of water, wilting its foliage. It also stains the wood with blue streaks, which destroys its commercial value. [1] The results of such beetle outbreaks could be devastating for the lumber industry in that area because of the amount of time required for natural regression to take place. [6] When this cycle affects the lumber industries by attacking spruce tree farms, they become known as serious pests. [9]
Spruce beetles usually infest the lower and middle parts of trunks. Trees that have been attacked are easy to recognize by concentrations of brown dust from bark at the basal areas of stems and trunks. However, sometimes apparently infected trees with green crowns can be without bark because of larval and woodpecker activity. Other common ways that infection can be detected is the presence of red-brown dust (frass) in bark crevices, many round exit holes, or small pitch tubes extruding from the bark. Large populations can be detected from a distance by patches of red foliage. [10]
Interventions for beetle outbreaks are controversial in locations such as the Šumava National Park in the Bohemian Forest of the Czech Republic. Some authorities suggest that outbreaks be allowed to run their course, even at the expense of most of the forest. Others, including the lumber industry, request intervention. [2] Some experts argue that salvage logging tends to have a greater negative effect on the vegetation than the bark beetle outbreak alone. A study of the effects of forestry interventions on the herb and moss layers of infested mountain spruce forests suggest that without intervention the forests do eventually recover. [11] Salvage logging also had negative effects on the composition of species, delaying recovery.
Several methods have been proposed to prevent the start of beetle outbreaks. Some suggest using “trap trees” at the beginning of each reproductive cycle. This should be done in March, May, and in late June or early July. The trap trees should be debarked when distinct larval galleries with small larvae are found. Another method is clearcutting, removing sections of trees at the first signs of infestation. Pheromone traps can capture thousands of bark beetles, [12] however, their real utility to decrease the damadges on the trees remains debated: some studies found a strong reduction of damage in locations with pheromone traps, [13] while others found no effect or even a slight increase in the risk of new attacks when pheromone traps were used. [14] Removal of attractive material, such as logs with bark, weakened trees, and windthrow, may help prevent outbreaks.
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 in which they cultivate 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 attack 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.
The Asian long-horned beetle, also known as the starry sky, sky beetle, or ALB, is native to the Korean Peninsula, northern and southern China, and disputably in northern Japan. This species has now been accidentally introduced into the eastern United States, where it was first discovered in 1996, as well as Canada, and several countries in Europe, including Austria, France, Germany, Italy and UK.
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 mountain pine beetle is a species of bark beetle native to the forests of western North America from Mexico to central British Columbia. It has a hard black exoskeleton, and measures approximately 5 millimetres, about the size of a grain of rice.
The ant beetle, also known as the European red-bellied clerid, is a medium size insect, rather soft-bodied, with strong mandibles that can tear between the hard sclerotized integument of bark beetles. Larvae and adults are common predators of bark beetles in Europe.
Cleridae are a family of beetles of the superfamily Cleroidea. They are commonly known as checkered beetles. The family Cleridae has a worldwide distribution, and a variety of habitats and feeding preferences.
Tomicus piniperda, the common pine shoot beetle, is a bark beetle native throughout Europe, northwestern Africa, and northern Asia. It is one of the most destructive shoot-feeding species in northern Europe.
Dendroctonus rufipennis, the spruce beetle, is a species of bark beetle native to British Columbia, Newfoundland and Labrador, Nova Scotia, Ontario, Quebec, Northern Manitoba, the Yukon, Alaska, Colorado, Wyoming, Montana, and Maine. They are known to destroy forests of spruce trees including Engelmann, White, Sitka, and Colorado blue spruce. Adults average 4 to 7 mm in length.
Dendroctonus frontalis, the southern pine beetle, often shortened to simply SPB, is a species of bark beetle native to the forests of the southern United States, Mexico and Central America. It has recently expanded its range to the northeastern United States, where it is considered an invasive species and has destroyed massive amounts of pine forest.
Tetropium fuscum, the brown spruce longhorn beetle, is a species of beetle in the family Cerambycidae. It was described by Johan Christian Fabricius in 1787. Tetropium fuscum is native to Europe and Northern Asia, and has been introduced to Nova Scotia, Canada. Brown spruce longhorn is a pest of spruce trees.
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.
The foamy bark canker is a disease affecting oak trees in California caused by the fungus Geosmithia sp. #41 and spread by the Western oak bark beetle. This disease is only seen through the symbiosis of the bark beetles and the fungal pathogen. The bark beetles target oak trees and bore holes through the peridermal tissues, making tunnels within the phloem. The fungal spores are brought into these tunnels by the beetles and begin to colonize the damaged cells inside the tunnels. Symptoms of the developing fungus include wet discoloration seeping from the beetle entry holes as the fungus begins to consume phloem and likely other tissues. If bark is removed, necrosis of the phloem can be observed surrounding the entry hole(s). As the disease progresses, a reddish sap and foamy liquid oozes from entry holes, thus giving the disease the name foamy bark canker. Eventually, after the disease has progressed, the tree dies. This disease is important because of its detrimental effects on oak trees and its ability to spread to several new Californian counties in just a couple of years.
Platypus apicalis, known by its common name the New Zealand pinhole boring beetle, is a wood-boring beetle endemic to New Zealand and found throughout the North and South Island in a range of environments.
Dendroctonus valens, the red turpentine beetle, is a species of bark beetle native to the forests of North America, Mexico, Guatemala and Honduras. It has been introduced to China where it has become invasive. In its native range it causes little damage, but in China it is a destructive pest and has killed more than six million pine trees.
Verbenol (2-pine-4-ol) is a group of stereoisomeric bicyclic monoterpene alcohols. These compounds have been found to be active components of insect pheromones and essential oils.
Dendroctonus adjunctus, the roundheaded pine beetle, is a species of bark beetle in the family Curculionidae found in North America. A parasite, the roundheaded pine beetle feeds on and eventually kills pine trees of several species in Guatemala, Mexico, and the Southern United States.
The current bark beetle infestation in the Rocky Mountain region of the United States was first detected in 1996. It involved the Mountain pine beetle, which has since spread across millions of acres of dense forest land. In addition, Spruce beetle populations have also been growing in the area in recent years and are further contributing to the existing outbreak. One of the main factors limiting bark beetle population growth is the temperature they can survive at and climate change has raised the average temperature in the region resulting in warmer winters and hotter, drier summers. This not only sped up the bark beetle reproduction process by providing more time per year for them to complete their developmental stages, moisture stressing due to hotter temperatures also weakens the trees’ defense against attacks by reducing resin production. Furthermore, forest management has also played a significant role as many forests in the region have very dense tree populations which facilitates faster spreading from tree to tree, as well as weakening tree defenses further by stressing them through excessive competition.
Ips cembrae, known generally as larch bark beetle or eight-toothed larch bark beetle, is a species of typical bark beetle in the family Curculionidae. Its habitat is Euro-Siberian, ranging from sea level to sub-alpine. It was first recorded in Great Britain in 1955. Populations were said to be found in Japan and China, but further research determined that those were actually Ips subelongatus.
Xyleborus dispar is a species of bark beetle commonly called the Pear blight beetle, or the European shothole borer. It is an invasive species in North America, and can be a pest in orchards and forests throughout its range.
Media related to Ips typographus at Wikimedia Commons
Data related to Ips typographus at Wikispecies| Authority control databases: National |
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