Monochamus

{{Short description|Genus of beetles}} {{About|the longhorn beetle genus Monochamus|the longhorn beetle sometimes known as the sawyer|Prionus coriarius}} {{Automatic taxobox | image = Beetle June 2008-1.jpg | image_caption = ''Monochamus galloprovincialis'' | taxon = Monochamus | authority = Dejean, 1821 | synonyms = *''Monohammus'' Dahl, 1823 (Suppr.) *''Monachammus'' Gray 1832 (Missp.) *''Monohammus'' Dejean 1835 (Emend.) *''Monohamus'' Guérin-Méneville 1844 (Missp.) *''Meges'' Pascoe 1866 }}

'''''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<ref name=TFD>The Free Dictionary (TFD) (2008): [http://www.thefreedictionary.com/genus+Monochamus Genus Monochamus]. Retrieved 23 March 2009.</ref> 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.

If sawyer beetles infect freshly cut pine logs, they can cause a 30–40% loss in value due to the tunnels their larvae bore. It is important to process logs within a few weeks of cutting or store them in water to minimize damage.<ref>[http://www.dec.ny.gov/docs/lands_forests_pdf/sawyer.pdf Douglas Allen, "Sawyer Beetles", New York Forest Owner, May 1994]</ref> Some species are known to transport phoretic ''Bursaphelenchus'' nematodes, including ''B. xylophilus'' which causes pine wilt disease.<ref name=KSU>Kansas State University Extension Horticulture (KSU-EH) (2005): [http://www.oznet.ksu.edu/dp_hfrr/extensn/problems/pinewilt.htm Pine Wilt] {{webarchive|url=https://archive.today/19970814175527/http://www.oznet.ksu.edu/dp_hfrr/extensn/problems/pinewilt.htm |date=14 August 1997}}. Version of 28 February 2005. Retrieved 23 March 2009.</ref>

== Description == Beetles in this genus are black or mottled gray in colour. Like other Lamiinae, the head is oriented vertically with ventral mouthparts. The scape (first antennal segment) has a circatrix, a carinate ring or scar-like area near the tip. Antennae of females are roughly as long as the body, while antennae of males are twice as long. The tarsal claws are divergent.<ref>{{Cite web |title=Genus Monochamus - Sawyers |url=https://bugguide.net/node/view/277 |access-date=2023-03-16 |website=bugguide.net}}</ref><ref>Benzel, J. S. 2015. [https://idtools.org/pdfs/high/Monochamus_spp_high.pdf Screening aid: Pine sawyer beetles, Monochamus sutor (Linnaeus) and M. alternatus Hope]. Identification Technology Program (ITP), USDA-APHIS-PPQ-S&T, Fort Collins, CO. 7 pp.</ref>

== Life cycle == Adults feed within the crowns of healthy trees. Adult females oviposit (lay eggs) in slits in the bark of dying or dead trees. Larvae hatch from eggs and develop in wood, passing through several instars. Next is a pupal stage. In spring, new adults emerge, starting the life cycle again.<ref name=":0">{{Citation |last1=Gibbs |first1=J.N. |title=PATHOLOGY {{!}} Insect Associated Tree Diseases |date=2004 |url=https://linkinghub.elsevier.com/retrieve/pii/B0121451607000703 |encyclopedia=Encyclopedia of Forest Sciences |pages=802–808 |access-date=2023-03-20 |publisher=Elsevier |language=en |doi=10.1016/b0-12-145160-7/00070-3 |isbn=978-0-12-145160-8 |last2=Webber |first2=J.F.|url-access=subscription }}</ref>

== Association with nematodes == The pine wood nematode ''Bursaphalenchus xylophilous'' is transmitted by several ''Monochamus'' species, and its life cycle is tied with that of its vector.<ref name=":0" />

When nematode-infested adult ''Monochamus'' feed on healthy trees, they create wounds that allow nematodes to enter. In a susceptible host tree, nematodes breed in the xylem and eventually kill the tree. In a resistant host, the nematodes die instead.<ref name=":0" />

When nematode-infested adult ''Monochamus'' oviposit in dying or dead trees, the slits they make in the bark for their eggs also allow nematodes to enter. Nematodes reproduce and feed on wood cells or fungi. Eventually, new ''Monochamus'' adults emerge from pupae, and while these are still callow, nematodes enter them via the thoracic spiracles.<ref name=":0" />

== Associations with other organisms == Bark beetles oviposit on trees at around the same time as ''Monochamus,'' and they transmit blue stain fungi. ''Bursaphalenchus'' nematodes feed on this fungi, and the combination of fungi and nematodes may help in overcoming host tree defences, creating a more suitable habitat for bark beetles and ''Monochamus''.<ref>{{Citation |last1=Hofstetter |first1=Richard W. |title=Symbiotic Associations of Bark Beetles |date=2015 |url=https://linkinghub.elsevier.com/retrieve/pii/B978012417156500006X |work=Bark Beetles |pages=209–245 |access-date=2023-03-20 |publisher=Elsevier |language=en |doi=10.1016/b978-0-12-417156-5.00006-x |isbn=978-0-12-417156-5 |last2=Dinkins-Bookwalter |first2=Jamie |last3=Davis |first3=Thomas S. |last4=Klepzig |first4=Kier D.|url-access=subscription }}</ref> Additionally, ''Monochamus'' compete with bark beetles for resources, prey on them (intraguild predation) and use their semiochemicals as kairomones.<ref>{{Citation |last1=Raffa |first1=Kenneth F. |title=Natural History and Ecology of Bark Beetles |date=2015 |url=https://dipot.ulb.ac.be/dspace/bitstream/2013/220716/5/Raffa-Gregoire-Lindgren_2015.pdf |work=Bark Beetles |pages=1–40 |access-date=2023-03-20 |publisher=Elsevier |language=en |doi=10.1016/b978-0-12-417156-5.00001-0 |isbn=978-0-12-417156-5 |last2=Grégoire |first2=Jean-Claude |last3=Staffan Lindgren |first3=B.}}</ref>

Some species of braconid wasps in the genus ''Atanycolus'' are parasitoids of ''Monochamus'', along with other wood-boring beetles.<ref>{{Citation |last1=Quicke |first1=Donald L.J. |title=Subfamily Braconinae Nees von Esenbeck, 1811 |date=2022 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780323960991000042 |work=Braconidae of the Middle East (Hymenoptera) |pages=178–238 |access-date=2023-03-20 |publisher=Elsevier |language=en |doi=10.1016/b978-0-323-96099-1.00004-2 |isbn=978-0-323-96099-1 |last2=Gadallah |first2=Neveen Samy |last3=Ghahari |first3=Hassan |last4=Shaw |first4=Scott Richard|url-access=subscription }}</ref>

The black-backed woodpecker is a predator on larvae of wood-boring beetles, including ''Monochamus''.<ref>{{Cite journal |last1=Irwin |first1=Larry L. |last2=Riggs |first2=Robert A. |last3=Verschuyl |first3=Jacob P. |date=2018 |title=Reconciling wildlife conservation to forest restoration in moist mixed-conifer forests of the inland northwest: A synthesis |url=https://linkinghub.elsevier.com/retrieve/pii/S0378112718303268 |journal=Forest Ecology and Management |language=en |volume=424 |pages=288–311 |doi=10.1016/j.foreco.2018.05.007|bibcode=2018ForEM.424..288I |url-access=subscription }}</ref>

==Taxonomy== The genus is very large, and its boundaries have varied considerably over time, with many species placed in this genus that have long since been removed, and species placed in other genera that have been added, and there are at least 20 subgenera presently recognized by most authorities.<ref>[https://species.wikimedia.org/wiki/Monochamus ''Monochamus'']</ref>

===Species=== [[File:Notable Sawyer.jpg|right|thumb|Notable sawyer (''M. notatus'')]] [[File:Ontario Beetle - topview.jpg|thumb|Spotted pine sawyer (''M. maculosus'')]] {{div col|colwidth=25em}} * ''Monochamus abruptus'' Holzschuh, 2015 * ''Monochamus accri'' (Dillon & Dillon, 1959) * ''Monochamus adamitus'' Thomson, 1857 * ''Monochamus affinis'' Breuning, 1938 * ''Monochamus alboapicalis'' (Pic, 1934) * ''Monochamus alboscutellaris'' Breuning, 1977 * ''Monochamus alternatus'' Hope, 1842 – Japanese pine sawyer beetle * ''Monochamus aparus'' (Jordan, 1903) * ''Monochamus asiaticus'' (Hayashi, 1962) * ''Monochamus asper'' Breuning, 1935 * ''Monochamus atrocoeruleogriseus'' Gilmour, 1956 * ''Monochamus balteatus'' Aurivillius, 1903 * ''Monochamus basifossulatus'' Breuning, 1938 * ''Monochamus basigranulatus'' Breuning, 1952 * ''Monochamus basilewskyi'' Breuning, 1952 * ''Monochamus benito'' (Dillon & Dillon, 1959) * ''Monochamus bialbomaculatus'' Breuning, 1948 * ''Monochamus bimaculatus'' Gahan, 1888 * ''Monochamus binigricollis'' Breuning, 1965 * ''Monochamus binigromaculatus'' Breuning, 1959 * ''Monochamus blairi'' (Breuning, 1936) * ''Monochamus bootangensis'' Breuning, 1947 * ''Monochamus borchmanni'' Breuning, 1959 * ''Monochamus buquetii'' (Thomson, 1858) [= ''tuberosus''] * ''Monochamus burgeoni'' Breuning, 1935 * ''Monochamus camerunensis'' Aurivillius, 1903 * ''Monochamus carolinensis'' (Olivier, 1792) – Carolina sawyer * ''Monochamus clamator'' (LeConte, 1852) – spotted pine sawyer * ''Monochamus conradti'' Breuning, 1961 * ''Monochamus convexicollis'' Gressitt, 1942 * ''Monochamus dayremi'' Breuning, 1935 * ''Monochamus densepunctatus'' Breuning, 1980 * ''Monochamus dentator'' (Fabricius, 1793) * ''Monochamus desperatus'' Thomson, 1857 * ''Monochamus diores'' (Dillon & Dillon, 1959) * ''Monochamus dubius'' (Gahan, 1894) * ''Monochamus fisheri'' Breuning, 1944 * ''Monochamus flavosignatus'' Breuning, 1947 * ''Monochamus flavovittatus'' Breuning, 1935 * ''Monochamus foraminosus'' Holzschuh, 2015 * ''Monochamus foveatus'' Breuning, 1961 * ''Monochamus foveolatus'' Hintz, 1911 [= ''unicolor''] * ''Monochamus franzae'' (Dillon & Dillon, 1959) * ''Monochamus galloprovincialis'' (Olivier, 1795) – black pine sawyer or timberman beetle * ''Monochamus gardneri'' Breuning, 1938 * ''Monochamus grandis'' Waterhouse, 1881 * ''Monochamus granulipennis'' Breuning, 1949 * ''Monochamus gravidus'' (Pascoe, 1858) * ''Monochamus griseoplagiatus'' Thomson, 1858 [= ''ochraceomaculatus''] * ''Monochamus guerryi'' Pic, 1903 * ''Monochamus guttulatus'' Gressitt, 1951 * ''Monochamus impluviatus'' Motschulsky, 1859 * ''Monochamus inexpectatus'' Breuning, 1935 * ''Monochamus irrorator'' (Chevrolat, 1855) [= ''plumbeus'', ''ruficornis''] * ''Monochamus itzingeri'' Breuning, 1935 * ''Monochamus jordani'' Nonfried, 1894 * ''Monochamus karlitzingeri'' Tavakilian & Jiroux, 2015 * ''Monochamus kashitu'' (Dillon & Dillon, 1959) * ''Monochamus kaszabi'' Heyrovský, 1955 * ''Monochamus kinabaluensis'' Hüdepohl, 1996 * ''Monochamus kivuensis'' Breuning, 1938 * ''Monochamus laevis'' Jordan, 1903 * ''Monochamus lamottei'' Lepesme & Breuning, 1952 * ''Monochamus latefasciatus'' Breuning, 1944 * ''Monochamus lepesmei'' Breuning, 1956 * ''Monochamus lineolatus'' (Dillon & Dillon, 1959) * ''Monochamus lunifer'' (Aurivillius, 1891) * ''Monochamus luteodispersus'' Pic, 1927 * ''Monochamus maculosus'' Haldeman, 1847 [= ''mutator''] – spotted pine sawyer * ''Monochamus marmorator'' Kirby in Richardson, 1837 – balsam fir sawyer * ''Monochamus maruokai'' Hayashi, 1962 * ''Monochamus masaoi'' Kusama & Takakuwa, 1984 * ''Monochamus mausoni'' Breuning, 1950 * ''Monochamus mbai'' Lepesme & Breuning, 1953 * ''Monochamus mediomaculatus'' Breuning, 1935 * ''Monochamus melaleucus'' Jordan, 1903 * ''Monochamus mexicanus'' (Breuning, 1950) * ''Monochamus millegranus'' Bates, 1891 * ''Monochamus murinus'' (Gahan, 1888) * ''Monochamus nigrobasimaculatus'' Breuning, 1981 * ''Monochamus nigromaculatus'' Gressitt, 1942 * ''Monochamus nigromaculicollis'' Breuning, 1974 * ''Monochamus nigroplagiatus'' Breuning, 1935 * ''Monochamus nigrovittatus'' Breuning, 1938 * ''Monochamus nitens'' Bates, 1884 * ''Monochamus notatus'' (Drury, 1773) – northeastern sawyer or notable sawyer<ref>John Acorn and Ian Sheldon. Bugs of Ontario. Edmonton, AB:Lone Pine Publ., 2003.</ref> * ''Monochamus obtusus'' Casey, 1891 – obtuse sawyer * ''Monochamus ochreomarmoratus'' Breuning, 1960 * ''Monochamus ochreopunctatus'' Breuning, 1980 * ''Monochamus ochreosparsus'' Breuning, 1959 * ''Monochamus ochreosticticus'' Breuning, 1938 * ''Monochamus olivaceus'' Breuning, 1935 * ''Monochamus omias'' Jordan, 1903 [= ''africanus''] * ''Monochamus pentagonus'' Báguena, 1952 * ''Monochamus pheretes'' (Dillon & Dillon, 1961) * ''Monochamus philomenus'' (Dillon & Dillon, 1959) * ''Monochamus pictor'' (Bates, 1884) * ''Monochamus principis'' Breuning, 1956 * ''Monochamus pseudotuberosus'' Breuning, 1936 * ''Monochamus quadriplagiatus'' Breuning, 1935 * ''Monochamus rectus'' Holzschuh, 2015 * ''Monochamus regularis'' (Aurivillius, 1924) * ''Monochamus reticulatus'' (Dillon & Dillon, 1959) * ''Monochamus rhodesianus'' Gilmour, 1956 * ''Monochamus roveroi'' Teocchi, Sudre & Jiroux, 2015 * ''Monochamus rubiginosus'' Teocchi, Sudre & Jiroux, 2014 * ''Monochamus ruspator'' (Fabricius, 1781) * ''Monochamus saltuarius'' Gebler, 1830 – Sakhalin pine beetle * ''Monochamus sargi'' (Bates, 1885) * ''Monochamus sartor'' (Fabricius, 1787) [incl. subspecies ''urussovii''] – black fir sawyer * ''Monochamus scabiosus'' (Quedenfeldt, 1882) [= ''centralis''] * ''Monochamus scutellatus'' (Say, 1824) – white-spotted sawyer or spruce sawyer<ref>[http://www.insectsofalberta.com/sprucesawyer.htm Spruce Sawyer], Insects of Alberta</ref> * ''Monochamus semicirculus'' Báguena, 1952 * ''Monochamus semigranulatus'' (Pic, 1925) * ''Monochamus serratus'' (Gahan, 1906) * ''Monochamus shembaganurensis'' Breuning, 1979 * ''Monochamus similis'' Breuning, 1938 * ''Monochamus sparsutus'' Fairmaire, 1889 * ''Monochamus spectabilis'' (Perroud, 1855) * ''Monochamus strandi'' Breuning, 1939 * ''Monochamus stuhlmanni'' Kolbe, 1894 * ''Monochamus subconvexicollis'' Breuning, 1967 * ''Monochamus subcribrosus'' Breuning, 1950 * ''Monochamus subfasciatus'' (Bates, 1873) [= ''fascioguttatus''] * ''Monochamus subgranulipennis'' Breuning, 1974 * ''Monochamus subtriangularis'' Breuning, 1971 * ''Monochamus sutor'' (Linnaeus, 1758) – pine sawyer * ''Monochamus taiheizanensis'' Mitono, 1943 * ''Monochamus talianus'' Pic, 1912 * ''Monochamus thoas'' (Dillon & Dillon, 1961) * ''Monochamus thomsoni'' (Chevrolat, 1855) * ''Monochamus titillator'' (Fabricius, 1775) – southern pine sawyer * ''Monochamus tonkinensis'' Breuning, 1935 * ''Monochamus transvaaliensis'' Gilmour, 1956 * ''Monochamus triangularis'' Breuning, 1935 * ''Monochamus tridentatus'' Chevrolat, 1833 * ''Monochamus tropicalis'' (Dillon & Dillon, 1961) * ''Monochamus vagus'' (Gahan, 1888) * ''Monochamus variegatus'' (Aurivillius, 1925) * ''Monochamus verticalis'' (Fairmaire, 1901) * ''Monochamus villiersi'' Breuning, 1960 * ''Monochamus x-fulvum'' Bates, 1884 {{div col end}}

==Gallery== <gallery> File:Pine Sawyer beetle 1.jpg File:Pine Sawyer beetle 2.jpg File:Pine Sawyer 3.jpg </gallery> Three pictures of two separate sawyers found in a planting of Scots pines in Kansas.

==References== {{Reflist}}

==External links== *{{Commons category-inline|Monochamus|''Monochamus''}} *{{Wikispecies-inline|Monochamus|''Monochamus''}} * [http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0329.2011.00733.x/abstract "Insect vectors of the pinewood nematode: a review of the biology and ecology of ''Monochamus'' species"]

Category:Monochamus Category:Lamiini Category:Taxa named by Pierre François Marie Auguste Dejean