Ips (beetle)

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Ips
Ips calligraphus crop.jpg
Ips calligraphus
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Curculionidae
Subfamily: Scolytinae
Tribe: Ipini
Genus: Ips
De Geer, 1775
Species

See text

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. [1] Some are known as introduced species in Australia and Africa. [2] Many species are pests of forest trees, especially pines and spruces. [3] They are known commonly as engraver beetles, [4] ips engraver beetles, [5] [6] and pine engravers. [7]

Contents

Description

Beetles of this genus are cylindrical in shape, 3 to 6.5 millimeters long, and reddish to black in color. The back end of the elytra is concave, and there is a ridge of three to six large spines on either side of the depression. The number and shape of the spines help to distinguish the species from one another. [3] The genus is distinguished from other groups in the tribe Ipini by the flat, oval shape of the clubs at the tips of the antennae and by details of the concavity in the elytra and of the male genitalia. [8]

The oblong white eggs are up to a millimeter long. The grub-like larvae are whitish with reddish heads and lack legs. [6]

Biology

These bark beetles live in and feed on the phloem in the inner layer of bark on trees. They usually inhabit dead, dying, and stressed trees, including fallen trees, cut logs, and slash. They can be found in trees that are already damaged by drought, lightning, human activity, or pest infestation. [6] They are specialists on conifers, attacking many species of pine ( Pinus ) and spruce ( Picea ). [3] [4] Less often, they are found on hemlocks ( Tsuga ) and firs ( Abies ). [6]

Most Ips, like most all beetles of the tribe Ipini, have a polygynous mating system with harems of females. [9] Typically, a male establishes a nuptial chamber in a log and produces an aggregation pheromone that attracts both males and females. The males dig additional chambers and each female joins one of the males, digging an extension onto his nuptial chamber where she deposits her eggs. A male may have a harem of up to eight females. [10] Exceptions are I. latidens and I. avulsus, which are monogamous in nature. [9]

The aggregation pheromones usually contain two or more active attractant compounds, such as ipsdienol, ipsenol, and cis-verbenol. [1] [11]

The beetles are called engravers because of the long, grooved galleries they excavate in the sapwood. [7] As the female digs her branch off of the male's nuptial chamber, she deposits eggs in individual niches along the walls. When the larva emerges, it digs a tunnel off of its niche. The multibranched engraved galleries that result are often Y-, H-, or I-shaped. [6] Ips galleries are clear and open, unlike those of some other bark beetles, which are filled with wood dust and frass. [4] [7]

The beetles grow and develop more quickly during the warmer seasons. In the summer, I. grandicollis and I. calligraphus can complete an entire life cycle in 25 days, and there can be up to eight generations per year. I. avulsus can complete a life cycle in just 18 days and have 10 generations per year. [6] After pupation, the new adult beetle disperses from its birthplace and can fly several miles to locate an appropriate host tree in which to breed. [6] Some species overwinter in aggregations inside the galleries, while others seek shelter in the outer bark layers or the leaf litter. [3]

Effects on trees

Ips avulsus infestation in loblolly pines (Pinus taeda) Ips avulsus damage on pinus taeda.jpg
Ips avulsus infestation in loblolly pines (Pinus taeda)

As native species, these beetles are a natural part of their environment, excavating snags and providing food for insectivores. [7] I. typographus is described as "an essential component of every spruce forest ecosystem" as it digs through dead and dying wood tissue, helping to initiate the process of decomposition. [12] In an abundance of dead and dying trees, after windthrow events, for instance, the beetles take advantage of plentiful food and shelter resources and their populations increase drastically. If the resources then dwindle, the large populations move into stands of healthy trees and become a problematic infestation. [12] Their damage is usually not as severe as that of certain beetles in the genus Dendroctonus , which sometimes share the habitat. [3] [6] Ips outbreaks are less common and usually shorter in duration, [3] though severe outbreaks of Ips typographus in Europe in the 1990s inspired many new research studies of ips engravers. [12]

A living tree can be killed by the feeding activity of adults and larvae, which damages the phloem in such a way that the tree is girdled. The beetles also introduce several species of fungi which invade and infect the wood, blocking the xylem. The first sign of an Ips infestation in a tree may be the discoloration of the needles that occurs when fungi block the xylem and prevent water transport to the foliage. [6] Several species of blue stain fungus can be vectored by the beetles, including those of the genera Ophiostoma and Ceratocystis . [12]

Other signs of Ips infestation include particles of wood dust accumulating on the bark, foliage, and nearby objects as a result of the beetles' tunneling activity. The wood dust can mix with resin that bleeds from the injury site, creating whitish or reddish pitch tubes, [6] but these are more common in Dendroctonus infestations. [3] Woodpeckers spend time on infested trees, chipping off bark as they forage for the beetles. [4]

Management

Insecticides are not effective for active Ips infestations. Instead they are used to prevent the beetles' spread to healthy trees, such as landscaping conifers, newly transplanted trees, and healthy stands adjacent to outbreaks. The beetles are attracted to freshly cut wood, so logs and slash are chipped, dried, or removed from vulnerable areas. Infested wood can be chipped, stripped of bark, or solarized in plastic to kill the beetles. [4]

If the sounds of related but different species of beetles, such as western pine beetles and southern pine beetles (which both feed on pinyon but never live together), are played into a tree the beetles present will tear each other apart. [13]

Taxonomy

There are 37 species in the genus. [14] In a 2001 revision it was divided into four subgenera. [8]

Ips sexdentatus in gallery Ips sexdentatus gallery crop.jpg
Ips sexdentatus in gallery
Ips typographus Ips typographus.jpg
Ips typographus
Ips latidens Ips latidens.jpg
Ips latidens

Species include: [8]

Genus Pseudips contains three species transferred from Ips in 2000: P. concinnus, P. mexicanus, and P. orientalis. [17]

See also

Related Research Articles

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.

<span class="mw-page-title-main">Bark beetle</span> Subfamily of beetles

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.

<i>Thanasimus formicarius</i> Species of beetle

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.

<i>Cryphalus</i> Genus of beetles

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.

<i>Dendroctonus</i> Genus of beetles

Dendroctonus is a genus of bark beetles. It includes several species notorious for destroying trees in the forests of North America. The genus has a symbiotic relationship with many different yeasts, particularly those in the genera Candida and Pichia that aid in digestion and pheromone production.

<span class="mw-page-title-main">Ipini</span> Tribe of beetles

Ipini is a tribe of bark beetles. It is a monophyletic group.

<span class="mw-page-title-main">European spruce bark beetle</span> Species of beetle

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.

<i>Dendroctonus frontalis</i> Species of beetle

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.

<i>Hylastes ater</i> Species of beetle

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."

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.

<i>Ips grandicollis</i> Species of beetle

Ips grandicollis, known generally as eastern five-spined engraver, is a species of typical bark beetle in the family Curculionidae. Other common names include the eastern five-spined ip and southern pine engraver. Ips grandicollis use trap trees of the genus Pinus as food and a habitat.

<i>Ips confusus</i> Species of beetle

Ips confusus, known generally as the pinyon pine beetle or pinyon ips, is a species of typical bark beetle in the family Curculionidae. It is found in Central America and North America.

<i>Ips avulsus</i> Species of beetle

Ips avulsus, the small southern pine engraver, is a species of typical bark beetle in the family Curculionidae. The pheromones ipsenol, ipsdienol, and lanieron combined attract the most colonization in the host material in regards to the chemical ecology of the small southern pine engraver, which also effects their reproduction processes.

<i>Xyleborus affinis</i> Species of beetle

Xyleborus affinis, the sugarcane shot-hole borer, is a species of ambrosia beetle in the family Curculionidae. It is found on all continents with woodlands and is one of the most widespread ambrosia beetles internationally, primarily in areas with humid tropical climates like Florida. Like other ambrosia beetles, Xyleborus affinis is attracted to dead fallen logs in early stages of decay. Due to the presence of X. affinis on moist timber, this species is mistakenly believed to be the cause of tree death. However, there is insufficient evidence to support their presence as a causal factor. Rather, these beetles are believed to target and accelerate the decay process of trees that are already deteriorated and weak.

<i>Ips pini</i> Species of beetle

Ips pini, also known as the pine engraver or North American pine engraver, is a species of typical bark beetle in the family Curculionidae found primarily in North America. These beetles are subcategorized by the distinctive geographic ranges in which they are found. A key distinguishing feature of different populations is how they produce the enantiomeric composition of ipsdienol, the major pheromone produced by males of this species.

<i>Ips cembrae</i> Species of beetle

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.

<i>Cryphalus piceae</i> Species of beetle

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.

<i>Cryphalus saltuarius</i> Species of beetle

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.

<i>Cryphalus abietis</i> Species of beetle

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.

<i>Cryphalus dorsalis</i> Species of beetle

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.

References

  1. 1 2 Birgersson, G., et al. (2012). Pheromone production, attraction, and interspecific inhibition among four species of Ips bark beetles in the southeastern USA. Psyche 2012. Article 532652
  2. ↑ Buhroo, A. A. and F. Lakatos. (2011). Molecular and morphological diagnostic markers for the Himalayan Ips DeGeer species (Coleoptera: Curculionidae: Scolytinae). Zootaxa 3128, 47–57.
  3. 1 2 3 4 5 6 7 Ips species of the western United States. Bark and Wood Boring Beetles of the World. Bugwood Network. 2006.
  4. 1 2 3 4 5 Cranshaw, W. and D. A. Leatherman. Ips Beetles. Archived 2015-09-24 at the Wayback Machine Colorado State University Extension. 2013.
  5. ↑ Ips spp. Bark and Wood Boring Beetles of the World. Bugwood Network. 2006.
  6. 1 2 3 4 5 6 7 8 9 10 Eickwort, J. M., et al. Ips engraver beetles (Ips spp.) EENY-388. Entomology and Nematology. University of Florida IFAS. Published 2006, updated 2012.
  7. 1 2 3 4 Fairweather, M. L., et al. Field Guide to Insects and Diseases of Arizona and New Mexico Forests. USDA Forest Service, Southwestern Region. 2006.
  8. 1 2 3 Cognato, A. I. and A. P. Vogler. (2001). Exploring data interaction and nucleotide alignment in a multiple gene analysis of Ips (Coleoptera: Scolytinae). [ dead link ]Syst Biol 50(6) 758-80.
  9. 1 2 Reid, M. (1999). Monogamy in the bark beetle Ips latidens: ecological correlates of an unusual mating system. Ecological Entomology 24(1), 89–94.
  10. ↑ Symonds, M. R., et al. (2012). Reproductive consequences of male arrival order in the bark beetle, Ips grandicollis. Journal of Insect Behavior 25(4), 401–07.
  11. ↑ Symonds, M. R. and M. A. Elgar. (2004). The mode of pheromone evolution: evidence from bark beetles. Proceedings of the Royal Society of London, Series B: Biological Sciences 271(1541), 839–46.
  12. 1 2 3 4 Wermelinger, B. (2004). Ecology and management of the spruce bark beetle Ips typographus—a review of recent research. Archived 2015-06-10 at the Wayback Machine Forest Ecology and Management 202(1), 67–82.
  13. ↑ Rothenberg, David (2013). Bug Music, p.137. St. Martin's Press. ISBN   978-1-250-00521-2.
  14. ↑ Douglas, Hume B.; Cognato, Anthony I; Grebinnikov, Vasily; Savard, Karine (2019). "Dichotomous and matrix-based keys to the Ips bark beetles of the World (Coleoptera: Curculionidae: Scolytinae)". Canadian Journal of Arthropod Identification (38): 234. Retrieved 10 November 2019.
  15. ↑ Zhang, Q. H., et al. (2009). Aggregation pheromone of the Qinghai spruce bark beetle, Ips nitidus Eggers. Journal of Chemical Ecology 35(5), 610.
  16. ↑ Cognato, A. I. and J. H. Sun. (2007). DNA based cladograms augment the discovery of a new Ips species from China (Coleoptera: Curculionidae: Scolytinae). Cladistics 23(6), 539–51.
  17. ↑ Cognato, A. I. (2000). Phylogenetic analysis reveals new genus of Ipini bark beetle (Scolytidae). Annals of the Entomological Society of America 93(3), 362–66.
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