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Species
Ips typographus (DeGreer, 1775)
IUCN
NCBI
EOL Text
The study of host-pathogen interaction, as well as the vector (Ips typographus) is one of the key tools in managing pest outbreak and damage to the Norway spruce. Research into genomics will help scientists to understand what genes are important for resistance to the host.Molecular study will help to isolate resistant as well as susceptible stands of Norway spruce which in turn will inform pest management for the future.Pest management of Ips typographus can be carried out effectively and in an environmentally-friendly manner by methods of control based on scientists' knowledge of insect-chemical communication. The development of negative semiochemical signals away from host selection of the bark beetle have proved more successful in some cases than the more traditional approach of mass trapping with pheromones.Natural enemies such as the Eurasian 3-toed woodpecker (Picoides tridactylus) predate on the larvae of bark beetles. Though successful in maintaining equilibrium amongst species, natural enemies such as this bird could not mitigate the effects of a serious pest outbreak.
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Rights holder/Author | Dr Beulah Garner, Natural History Museum |
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The beetle introduces a fungus, Ceratocystis polonica - the blue-stain fungus - to the tree, which interferes with the tree’s resin production. Without this resin the tree is unable to repel potential beetle pest attack. This is why it is more advantageous to the beetle to attack damaged or dying wood. When the beetle is forced to attack live stands, its population must be larger in number to introduce enough fungus to attack a living tree, which under normal circumstances, would be able to produce enough defensive resin to fend off the attack. This is achieved by the aggregation pheromone produced by the males, (methyl butenol and cis-verbenol) though females can produce some cis-verbenol.The pheromone is also used to attract mates. The male usually enjoys a harem of up to 4 females. The male prepares a ‘nuptial chamber’ beneath the bark to make way for the female to excavate larval tunnels, along which she will lay her eggs. This is a linear ‘gallery’ of chambers which increase in size as the larvae grow bigger. The tunnels radiate at right-angles from the central chamber and reach between 10cm to 20cm in length. They are usually 3-armed but can also be multi-branched.These tunnels are excavated in the phloem layer which is 2–4mm thick. The phloem transports sugars and amino acids throughout the tree, providing nutrition for root development and needle growth.The male regulates the number of females by blocking the entrance hole with his spiny rear end. This ensures there is no adverse competition amongst the larvae and also prevents other pest attacks on the vulnerable soft-bodied larvae.The female lives for approximately 3 weeks in which time she is capable of laying approximately 50 eggs. Egg production is temperature-dependant, with the low threshold at approximately 11°C. For juvenile development, optimum temperature is approximately 30°C.This beetle’s life-cycle from reproduction to adulthood (full metamorphosis) is completed between 7–11 weeks.A key to its success is its ability to complete more than one generation per year, dependant on favourable temperature.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Dr Beulah Garner, Natural History Museum |
Source | No source database. |
United States
Origin: Exotic
Regularity: Regularly occurring
Currently: Present
Confidence: Confident
Type of Residency: Year-round
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | NatureServe |
Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Ips+typographus |
Foodplant / internal feeder
larva of Ips typographus feeds within cambium of Abies
Foodplant / internal feeder
larva of Ips typographus feeds within cambium of Picea
Foodplant / internal feeder
larva of Ips typographus feeds within cambium of Pinus
Ips typographus is generally associated with damaged trees, windblown from gales or recently felled trees. If there is a plentiful source of this type of habitat, population numbers can increase rapidly, causing the beetles to move on to nearby healthy tree stands. It is at this point that the beetle becomes a serious pest.Signs of infestation include:
- exit holes (2–3mm)
- frass - the debris left behind from the beetles’ excavation
- very small tubes of resin extruding from the bark
It is Ceratocystis polonica, a fungus carried by the beetle which causes blue stain in the spruce and causes the most severe damage, rather than the gallery boring itself. This blue stain fungus will kill healthy trees, and also stain the wood blue, thereby reducing the value of commercial stock. This is what makes this beetle a well-known economically important pest.The damage becomes evident within a few weeks of infestation, and in standing trees needles will first turn yellow and then brown as they defoliate.With global temperatures rising, this beetle can now inhabit altitudes beyond its original range (dispersal flights are initiated at 20°C and larval development as low as 8°C). This has implications for ecosystem management.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Dr Beulah Garner, Natural History Museum |
Source | No source database. |
The following is a representative barcode sequence, the centroid of all available sequences for this species.
There is 1 barcode sequence available from BOLD and GenBank.
Below is the sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen.
Other sequences that do not yet meet barcode criteria may also be available.
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Barcode of Life Data Systems (BOLDS) Stats
Public Records: 12
Specimens with Barcodes: 14
Species With Barcodes: 1
United States
Rounded National Status Rank: NNA - Not Applicable
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | NatureServe |
Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Ips+typographus |
Rounded Global Status Rank: GNR - Not Yet Ranked
License | http://creativecommons.org/licenses/by-nc/3.0/ |
Rights holder/Author | NatureServe |
Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=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.
Contents
Biology of the species[edit]
Morphology[edit]
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 4 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.
Life cycle and interactions[edit]
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 miles 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.
Dispersal ability[edit]
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]
Impact[edit]
Ecological[edit]
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] Others disagree, because it is also an invasive species in the area.
Outbreak species, in general, assist in the renewal of the forest. Spruce beetles are detritivores. They feed on and break down dead plant matter, returning essential nutrients to the ecosystem. Also, they further the evolution of stronger, more resistant trees by instigating a range of adaptations to ward off their attacks.
Economical[edit]
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 invasive 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]
Detection[edit]
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 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]
Conservation[edit]
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.
Prevention and control methods[edit]
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 be used.[12] Removal of attractive material, such as logs with bark, weakened trees, and windthrow, may help prevent outbreaks.
See also[edit]
References[edit]
- ^ a b c Kirkendall, L. R. & M. Faccoli (2010). "Bark beetles and pinhole borers (Curculionidae, Scolytinae, Platypodinae) alien to Europe" (PDF). ZooKeys 56: 227–251. doi:10.3897/zookeys.56.529.
- ^ a b c Svoboda, M., et al. (2010). "Natural development and regeneration of a Central European montane spruce forest". Forest Ecology and Management 260 (5): 707–714. doi:10.1016/j.foreco.2010.05.027.
- ^ Horn, A., et al. (2009). "Complex postglacial history of the temperate bark beetle Tomicus piniperda L. (Coleoptera, Scolytinae)" (PDF). Heredity 103 (3): 238–247. doi:10.1038/hdy.2009.48. PMID 19401712.
- ^ Jankowiak, R. & M. Kolarik (2010). "Fungi associated with the fir bark beetle Cryphalus piceae in Poland". Forest Pathology 40 (2): 133–144. doi:10.1111/j.1439-0329.2009.00620.x.
- ^ Mezei, P., et al. (2011). "Population dynamics of spruce bark beetle in a nature reserve in relation to stand edges condition". Folia Oecologica 38 (1): 73–79.
- ^ a b c d Zhang, Q. & F. Schlyter (2010). "Inhibition of predator attraction to kairomones by non-host plant volatiles for herbivores: a bypass-trophic signal". PLoS One 5 (6): e11063. doi:10.1371/journal.pone.0011063. PMC 2883581. PMID 20548795.
- ^ a b Arthofer, W., et al. (2009). "Evidence for low-titre infections in insect symbioses: Wolbachia in the bark beetle Pityogenes chalcographus (Coleoptera, Scolytinae)". Environmental Microbiology 11 (8): 1923–1933. doi:10.1111/j.1462-2920.2009.01914.x. PMID 19383035.
- ^ Muller, J.; et al. (30 May 2008). "The European spruce bark beetle Ips typographus in a national park: from pest to keystone species". Springer Science+Business Media 17: 2979–3001. doi:10.1007/s10531-008-9409-1.
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(help) - ^ Lee, J. C. & S. J. Seybold (2010). "Host acceptance and larval competition in the banded and European elm bark beetles, Scolytus schevyrewi and S. multistriatus (Coleoptera: Scolytidae): potential mechanisms for competitive displacement between invasive species" (PDF). Journal of Insect Behavior 23 (1): 19–34. doi:10.1007/s10905-009-9192-1.
- ^ Seidl, R., et al. (2009). "Modelling bark beetle disturbances in a large scale forest scenario model to assess climate change impacts and evaluate adaptive". Regional Environmental Change 9 (2): 101–119. doi:10.1007/s10113-008-0068-2.
- ^ Jonášová, M. & K. Prach (2008). "The influence of bark beetles outbreak vs. salvage logging on ground layer vegetation in Central European mountain spruce forests" (PDF). Biological Conservation 141 (6): 1525–1535. doi:10.1016/j.biocon.2008.03.013.
- ^ Sevima, A. et al. (2010). "Screening of entomopathogenic fungi against the European spruce bark beetle, Dendroctonus micans (Coleoptera: Scolytidae)". Biocontrol Science and Technology 20 (1): 3–11. doi:10.1080/09583150903305737.
License | http://creativecommons.org/licenses/by-sa/3.0/ |
Rights holder/Author | Wikipedia |
Source | http://en.wikipedia.org/w/index.php?title=European_spruce_bark_beetle&oldid=620991440 |