Monochamus scutellatus

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Monochamus scutellatus
White-spotted Sawyer or Spruce Sawyer (Monochamus scutellatus), Lac Rapide.jpg
Monochamus scutellatus scutellatus
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Cerambycidae
Tribe: Lamiini
Genus: Monochamus
Species:
M. scutellatus
Binomial name
Monochamus scutellatus
(Say, 1824)
Subspecies
  • M. s. oregonensis
  • M. s. scutellatus

Monochamus scutellatus, commonly known as the white-spotted sawyer or spruce sawyer or spruce bug or a hair-eater, [1] is a common wood-boring beetle found throughout North America. [2] It is a species native to North America. [3]

Contents

Adults are large-bodied and black, with very long antennae; in males, they can be up to twice the body length, but in females they are only slightly longer than body length. Both sexes have a white spot on the base of the wings, and may have white spots covering the wings. Both males and females also have a spine on the side of the prothorax. [2] Most research done on M. scutellatus focuses on their relationship with burned forests and the logging industry, [2] [4] [5] [6] [7] with interest also being shown in their mating behaviours. [8] [9] [10]

Monochamus scutellatus oregonensis Longhorn Beetle Whitespotted Sawyer USA.jpg
Monochamus scutellatus oregonensis

Life history

Adults feed preferentially on members of the pine and spruce families for up to seven days after emerging between mid-June and mid-August. After mating, females chew small egg niches into dead or dying trees or logs, into which they deposit one egg each. [2] Both sexes mate repeatedly with different partners, and females have been found to lay between 15 and 20 eggs on average per lifetime. [2] Once the larvae hatch, they burrow into the phloem and to the cambium, where they continue to feed until emergence. Life cycles ranging from one to four years have been recorded in different areas and specific habitats. [2] About one week after pupae formation, adults emerge from their larval log by chewing through the bark. [2]

Habitat

In boreal forests where fire has altered the landscape, changes come to plant communities and carbon flux. [6] This change opens up opportunities for immigrant species to move into a competitor-free habitat. [4] Several groups of insects, including the genus Monochamus, have become adapted to exploit these conditions. M. scutellatus is a saproxylic insect, which means that at least part of its life cycle is dependent on either dead or dying wood. [6] For these beetles to successfully colonize a new habitat, such as an area that has been burned by forest fire, it must be of high enough quality and in close enough range.

Studies have shown that several Monochamus species use the pheromones of bark beetles as kairomones to find suitable host habitats quickly and efficiently, enabling them to devote time and energy to other activities. [11] In the cases of succession after fires, the abundance of M. scutellatus is positively correlated with the severity of the fire, the abundance and size of the burned trees, and the distance between burned and unburned land. [6] However, more larvae tend to be found in areas with a larger percentage of unburned forest within 500 metres, which may be related to the dietary requirements of the adult beetles. [4]

Adult females seem to prefer to lay their eggs in trees with thick bark and phloem, and consequently trees with diameters greater than 8–10 centimetres. These trees are more able to inhibit water loss during fires, preserving the quality preferred by females. [4]

Relationship with the logging industry

M. scutellatus contributes to the ecology of the forest and may impact logging activities. Wood-boring insects can degrade the wood aesthetically by boring holes, and also indirectly as vectors for fungi and nematodes which can cause structural damage. [5]

Allison et al. [11] extrapolated information from one mill in southern British Columbia to suggest that wood-boring insects could cause an annual loss of US$43.6 million per year in British Columbia. On the other hand, the logging industry also negatively impacts beetle populations. Because saproxylic insects rely on dead or dying wood to complete their life cycles, there must be constant migration between habitats as resources decompose and new areas for colonization appear. [12]

As such, if forest management interferes in natural succession patterns, by methods such as clearfelling, they may induce a gap in habitat continuity which can cause localized extinction of a species. [12] With the introduction of salvage logging, concerns have been raised about the long-term effects that this practice can have on ecosystems. Salvage logging can directly kill both adult beetles and their larvae by clearing land soon after forest fires. Delaying this practice for 3–4 years, enough time for populations to complete a life cycle, would help support the persistence of these saproxylic insects. [5]

The presence of M. scutellatus has been shown to be beneficial in nutrient cycling by affecting microbial activity, the amount of available nitrogen, and the germination of post-fire colonizing flora. [7] Therefore, although wood-boring beetles including M. scutellatus are considered pests of the logging industry, post-fire management strategies should not ignore their importance as nutrient cyclers and facilitators of plant growth. [7]

Reproduction and mate choice

As with many other insects, both intraspecies and interspecies competition occurs in M. scutellatus over resources. Hughes and Hughes [10] performed experiments to test the results of asymmetric contests of M. scutellatus and M. notatus, the eastern pine sawyer. They found that in M. scutellatus, females laid eggs that were fertilized by the male with whom they were currently sharing a pair-bond with, and the certainty of paternity decreases once the pair-bond is over. Consequently, females are the most valuable resource that males compete over.

As for the females, the majority of their inter- and intraspecies competition was over oviposition holes. Female M. scutellatus individuals often spend over 20 minutes using their mandibles to chew oviposition holes in the bark of trees, which makes a very loud noise and incurs substantial risk of detection by predators. [10] Therefore, it is greatly advantageous for females to steal holes chewed by other females to save time and risk.

The study found that both within and between species, contests between larger resource holders and smaller challengers usually do not escalate and the resource holder retains their territory, but contests between smaller resource holders and larger challengers are more likely to escalate to fighting with the pro- and mesolegs and biting of the legs and antennae. This is likely because Monochamus species have large, strong mandibles which are capable of biting off limbs or antennae, and escalated competitions are usually not worth the risk. [10]

M. scutellatus displays resource-defence polygyny, a mating system in which males defend necessary resources that females require for reproduction. [9] Resources in this case refer to the quality of tree trunk that the male has won; females prefer basal trunk regions with a large diameter. [8] Females then choose mates mainly on the basis of their resources, but when resources are equal, Hughes and Hughes [9] observed that they choose larger males preferentially. Although it has not been proven that large body size is inherited by offspring, it still may be an indicator of fitness and quality.

Related Research Articles

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Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta, also known as Coniferophyta or Coniferae. The division contains a single extant class, Pinopsida. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include cedars, Douglas-firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews. As of 2002, Pinophyta contained seven families, 60 to 65 genera, and more than 600 living species.

<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.

<span class="mw-page-title-main">Mountain pine beetle</span> Species of beetle

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.

<i>Odontotaenius disjunctus</i> Species of beetle

Odontotaenius disjunctus, the patent-leather beetle or horned passalus, is a saproxylic beetle in the family Passalidae which can grow to just over an inch-and-a-half long, weigh 1-2 grams and are capable of pulling 50 times their own weight. They have been used to study several aspects of general family characteristics since the early 1900s but remain a relatively unknown species within the diverse Coleoptera order.

<span class="mw-page-title-main">Woodboring beetle</span> Common name for a beetle that eats wood

The term woodboring beetle encompasses many species and families of beetles whose larval or adult forms eat and destroy wood. In the woodworking industry, larval stages of some are sometimes referred to as woodworms. The three most species-rich families of woodboring beetles are longhorn beetles, bark beetles and weevils, and metallic flat-headed borers. Woodboring is thought to be the ancestral ecology of beetles, and bores made by beetles in fossil wood extend back to the earliest fossil record of beetles in the Early Permian (Asselian), around 295-300 million years ago.

<i>Monochamus</i> Genus of beetles

Monochamus is a genus of longhorn beetles found throughout the world. They are commonly known as sawyer beetles or sawyers, as their larvae bore into dead or dying trees, especially conifers such as pines. They are the type genus of the Monochamini, a tribe in the huge long-horned beetle subfamily Lamiinae, but typically included in the Lamiini today.

<span class="mw-page-title-main">Spruce–fir forests</span> Spruce forest

Spruce–fir forests are type of forest found in the Northern Hemisphere dominated by spruce and fir trees. These forests are often considered to be climax forests, with the two main tree genera able to reproduce in their own shade.

<i>Bursaphelenchus xylophilus</i> Species of roundworm

Bursaphelenchus xylophilus, commonly known as pine wood nematode or pine wilt nematode (PWN), is a species of nematode that infects trees in the Pinus genus of coniferous trees and causes the disease pine wilt. While native to North America, it spread in the early 20th century to Japan and in the latter half of the century to other areas of Asia, including China, Taiwan, and Korea, as well as to Europe, including Portugal and Spain.

<i>Clytus arietis</i> Species of insect

Clytus arietis, the wasp beetle, is a wasp-mimicking longhorn beetle species in the genus Clytus.

<span class="mw-page-title-main">Boreal forest of Canada</span> Canadian biome characterized by coniferous forests

Canada's boreal forest is a vast region comprising about one third of the circumpolar boreal forest that rings the Northern Hemisphere, mostly north of the 50th parallel. Other countries with boreal forest include Russia, which contains the majority; the United States in its northernmost state of Alaska; and the Scandinavian or Northern European countries. In Europe, the entire boreal forest is referred to as taiga, not just the northern fringe where it thins out near the tree line. The boreal region in Canada covers almost 60% of the country's land area. The Canadian boreal region spans the landscape from the most easterly part of the province of Newfoundland and Labrador to the border between the far northern Yukon and Alaska. The area is dominated by coniferous forests, particularly spruce, interspersed with vast wetlands, mostly bogs and fens. The boreal region of Canada includes eight ecozones. While the biodiversity of regions varies, each ecozone has a characteristic native flora and fauna.

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

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.

<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>Tetropium fuscum</i> Species of beetle

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.

<i>Ips</i> (beetle) Genus of beetles

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.

<i>Platypus apicalis</i> Wood-boring beetle endemic to New Zealand

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.

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

Dendroctonus valens, also known as the red turpentine beetle, is a species of bark beetle characterized by a dark-reddish brown hue. It is native to forests across North and Central America. In its adult form, these beetles range from six to ten millimeters in length. A notable characteristic about them is their use of acoustic signals and chemical cues when engaging in what is a very complex mating process.

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

Dendroctonus micans, the great spruce bark beetle, is a species of bark beetle native to the coniferous forests of Europe and Asia. The beetles burrow into the bark of spruce trees and lay eggs which develop into larvae that feed on the woody layers under the bark.

<i>Melanophila acuminata</i> Species of beetle

Melanophila acuminata, known generally as the black fire beetle or fire bug, is a species of metallic wood-boring beetle in the family Buprestidae. It is found in the Caribbean, Europe and Northern Asia, Central America, North America, and Southern Asia. They get their common name due to the fact that they swarm freshly burned conifer trees, which they find using sensors on their thorax. Adults are black and 7–11 mm in length.

<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.

Platypus quercivorus, the oak ambrosia beetle, is a species of weevil and pest of broad-leaved trees. This species is most commonly known for vectoring the fungus responsible for excessive oak dieback in Japan since the 1980s. It is found in Japan, India, Indonesia, New Guinea, and Taiwan.

References

  1. Spruce sawyer, Insects of Alberta
  2. 1 2 3 4 5 6 7 Raske, A. G. (1972). Biology and control of Monochamus and Tetropium, the economic wood borers of Alberta (Coleoptera: Cerambycidae). Northern Forest Research Centre Internal Report, Canadian Forestry Service, Edmonton, AB
  3. "Monochamus scutellatus". wiki.bugwood.org. Retrieved 2018-06-25.
  4. 1 2 3 4 Saint-Germain, M., Drapeau, P., and Hebert, C. (2004). Comparison of Coleoptera assemblages from a recently burned and unburned black spruce forests of northeastern North America. Biological Conservation, 118: 583 - 592
  5. 1 2 3 Saint-Germain, M. and Greene, D. F. (2009). Salvage logging in the boreal and cordilleran forests of Canada. The Forestry Chronicle, 85: 120 - 134
  6. 1 2 3 4 Boulanger, Y., Sirois, L., and Hebert, C. (2010). Distribution of saproxylic beetles in a recently burnt landscape of the northern boreal forest of Quebec. Forest Ecology and Management, 260: 1114 – 1123
  7. 1 2 3 Cobb, T. P., Hannam, K. D., Kischuk, B. E., Langor, D. W., Quideau, S. A., and Spence, J. R. (2010). Wood-feeding beetles and soil nutrient cycling in burned forests: implications of post-fire salvage logging. Agricultural and Forest Entomology, 12: 9 - 18
  8. 1 2 Hughes, A. L., and Hughes, M. K. (1982). Male size, mating success, and breeding habitat partitioning in the whitespotted sawyer Monochamus scutellatus (Say) (Coleoptera: Cerambycidae). Oecologia, 55: 258 - 263
  9. 1 2 3 Hughes, A. L., and Hughes, M. K. (1985). Female choice of mates in polygynous insect, the whitespotted sawyer Monochamus scutellatus. Behavioral Ecology and Sociobiology, 17: 385 – 387
  10. 1 2 3 4 Hughes, A. L., and Hughes, M. K. (1987). Asymmetric contests among sawyer beetles (Cerambycidae: Monochamus notatus and Monochamus scutellatus). Canadian Journal of Zoology, 65: 823 – 827
  11. 1 2 Allison, J.D., Borden, J.H., McIntosh, R.L., De Groot, P., and Gries, R. (2001). Kairomonal response by four Monochamus species (Coleoptera: Cerambycidae) to bark beetle pheromones. Journal of Chemical Ecology, 27: 633–646
  12. 1 2 Grove, S.J. (2002). Saproxylic insect ecology and the sustainable management of forests. Annual Review of Ecology and Systematics, 33: 1 – 23