{{short description|Genus of beetles}} {{Automatic taxobox | image = Chrysochus cobaltinus, CA.jpg | image_caption = ''Chrysochus cobaltinus'' | taxon = Chrysochus | display_parents = 2 | authority = Chevrolat ''in'' Dejean, 1836 | type_species = ''Chrysomela praetiosa''<br /><small>(= ''Chrysomela asclepiadea'' Pallas, 1773)</small> | type_species_authority = Fabricius, 1792 | synonyms = * ''Atymius'' <small>Gistel, 1848</small> * ''Eumolpus'' <small>sensu auct.</small> | synonyms_ref = <ref>{{cite journal|last=Bezděk|first=J.|year=2020|title=Review of the genus-level names proposed by Johannes Gistel in Chrysomelidae (Coleoptera)|journal=Acta Entomologica Musei Nationalis Pragae|volume=60|issue=1|pages=173–188|doi=10.37520/aemnp.2020.011|doi-access=free}}</ref> }}
'''''Chrysochus''''' is a genus of leaf beetles in the subfamily Eumolpinae. It is known from North America, Europe and Asia.
==Etymology== The name of the genus is derived from the Greek word {{wikt-lang|el|χρυσοχόος}} ({{transliteration|el|chrysochóos}}), meaning "goldsmith".<ref>{{cite encyclopedia|last=Chevrolat|first=L.A.A.|year=1843|chapter=Chrysochus|chapter-url=https://www.biodiversitylibrary.org/page/57479718|editor-last=d'Orbigny|editor-first=C.|title=Dictionnaire Universel d'Histoire Naturelle|volume=3|publisher=MM. Renard, Martinet et Cie.|place=Paris|page=652}}</ref>
==Taxonomic history== In 1836, the genus ''Chrysochus'' was first established by Louis Alexandre Auguste Chevrolat in Dejean's ''Catalogue des Coléoptères'', including the species ''Chrysomela asiatica'' <small>Pallas, 1771</small>, ''C. aurata'' <small>Fabricius, 1775</small> and ''C. pretiosa'' <small>Fabricius, 1792</small> (now ''Chrysochares asiaticus'', ''Chrysochus auratus'' and ''Chrysochus asclepiadeus'', respectively). ''Chrysomela praetiosa'' was designated as the type species of the genus by Sylvain Auguste de Marseul in 1864.<ref>{{cite journal|first1=Yves|last1=Bousquet|first2=Patrice|last2=Bouchard|year=2013 |title=The genera in the second catalogue (1833–1836) of Dejean's Coleoptera collection|journal=ZooKeys|issue=282|pages=1–219|doi=10.3897/zookeys.282.4401|pmc=3677338|pmid=23794836 |doi-access=free }}</ref>
The generic name ''Chrysochus'' <small>Chevrolat in Dejean, 1836</small> is a conserved name. It was threatened by ''Eumolpus'' in the sense used by Kugelann in Illiger, 1798, which included ''Chrysomela praetiosa''. An application to conserve ''Chrysochus'' and other names by suppressing ''Eumolpus'' <small>Illiger, 1798</small> was accepted by the International Commission on Zoological Nomenclature in 2012.<ref>{{cite journal|first1=A.G.|last1=Moseyko|first2=E.|last2=Sprecher-Uebersax|first3=I.|last3=Löbl|year=2010|title=Case 3519 ''Eumolpus'' Weber, 1801, ''Chrysochus'' Chevrolat in Dejean, 1836 and ''Bromius'' Chevrolat in Dejean, 1836 (Insecta, Coleoptera, chrysomelidae): proposed conservation of usage|journal=The Bulletin of Zoological Nomenclature|volume=67|issue=3|pages=218–224|doi=10.21805/bzn.v67i3.a10|s2cid=83763033}}</ref><ref>{{cite journal|author=ICZN|year=2012|title=Opinion 2298 (Case 3519) ''Eumolpus'' Weber, 1801, ''Chrysochus'' Chevrolat in Dejean, 1836 and ''Bromius'' Chevrolat in Dejean, 1836 (Insecta, Coleoptera, chrysomelidae): usage conserved|journal=The Bulletin of Zoological Nomenclature|volume=69|issue=2|pages=147–149|doi=10.21805/bzn.v69i2.a6|s2cid=83692416|quote=The Commission has conserved the usage of the generic names ''Eumolpus'' Weber, 1801, ''Chrysochus'' Chevrolat in Dejean, 1836 and ''Bromius'' Chevrolat in Dejean, 1836 by suppressing the name ''Eumolpus'' Illiger, 1798.}}</ref>
==Species== There are at least eight described species in ''Chrysochus''. Six are found in the Palearctic realm,<ref>{{cite book|last1=Moseyko|first1=A. G.|last2=Sprecher-Uebersax|first2=E.|year=2010|chapter=Eumolpinae|chapter-url=https://books.google.com/books?id=qt8zDwAAQBAJ&pg=PA620|editor-last1=Löbl|editor-first1=I.|editor-last2=Smetana|editor-first2=A.|title=Catalogue of Palaearctic Coleoptera. Volume 6. Chrysomeloidea|location=Stenstrup, Denmark|publisher=Apollo Books|pages=619–643|isbn=978-87-88757-84-2}}</ref> and only two are found in North America.
{| class="wikitable" |+ List of ''Chrysochus'' species |- ! Scientific name ! Authority ! Range ! Common name ! Image |- | ''Chrysochus asclepiadeus'' | (Pallas, 1773) | Widespread across Europe, also found in Kazakhstan and Turkey | | frameless |- | ''Chrysochus auratus'' | (Fabricius, 1775) | Eastern North America | Dogbane beetle | frameless |- | ''Chrysochus brevefasciatus'' | Pic, 1934<ref name="Pic1934">{{cite journal|last=Pic|first=M.|year=1934|title=Nouveautés diverses|url=http://brittlebooks.library.illinois.edu/brittlebooks_open/Books2011-09/picmau0001melexo/picmau0001melexov00000i00063/picmau0001melexov00000i00063.pdf|journal=Mélanges Exotico–Entomologiques|volume=63|pages=1–36}}</ref> | Shanghai, China | | |- | ''Chrysochus chinensis'' | Baly, 1859<ref name="Baly1859">{{cite journal|last=Baly|first=J. S.|year=1859|title=Descriptions of new genera and species of Phytophagous insects|journal=Annals and Magazine of Natural History|series=3|volume=4|issue=20|pages=124–128|doi=10.1080/00222935908697096}}</ref> | Central, North and Northeast China, Japan, Mongolia and the Russian Far East | | frameless |- | ''Chrysochus cobaltinus'' | LeConte, 1857 | Western United States and British Columbia | Blue milkweed beetle | frameless |- | ''Chrysochus globicollis'' | Lefèvre, 1888 | Northeast China, the Russian Far East and North Korea | | |- | ''Chrysochus goniostoma'' | Weise, 1889 | North and Northeast China, Mongolia, and the Russian Far East | | |- | ''Chrysochus sikhima'' | Jacoby, 1908<ref name="Jacoby1908"/> | Sikkim, India | | |}
Another species, ''Chrysochus mniszechi'', was described in 1877 by Édouard Lefèvre, from three specimens he had seen (one in the collection of {{ill|Georges Mniszech|fr}}, and two from Henry Deyrolle's). While he did not know where the specimens were collected from, Lefèvre thought that they probably came from North America.<ref name="Lefevre1877">{{cite journal|first=E.|last=Lefèvre|year=1877|title=Descriptions de Coléoptères nouveaux ou peu connus de la Famille des Eumolpides (2e partie)|url=https://biodiversitylibrary.org/page/8244637|journal=Annales de la Société Entomologique de France|series=5|volume=7|pages=309–326}}</ref>
The following species, all from the Oriental realm, were formerly included in ''Chrysochus''. They were transferred to the genera ''Parheminodes'' and ''Platycorynus'' in 2021:<ref name="Moseyko2021">{{cite journal|last=Moseyko|first=A.G.|year=2020|publication-date=15 January 2021|title=Notes on Asiatic Eumolpinae (Coleoptera, Chrysomelidae)|journal=Entomological Review|volume=100|issue=6|pages=843–862|doi=10.1134/S0013873820060123|s2cid=234621478 }}</ref> * ''Chrysochus conspectus'' <small>Lefèvre, 1890</small>: moved to ''Parheminodes'' * ''Chrysochus hageni'' <small>Jacoby, 1884</small>:<ref name="Jacoby1884">{{cite journal|last=Jacoby|first=M.|year=1884|title=Descriptions of new genera and species of phytophagous Coleoptera collected by Dr. B. Hagen at Serdang (East Sumatra)|url=https://www.biodiversitylibrary.org/page/9635686|journal=Notes from the Leyden Museum|volume=6|pages=201–230}}</ref> moved to ''Parheminodes'' * ''Chrysochus languei'' <small>Lefèvre, 1893</small>: moved to ''Platycorynus'' * ''Chrysochus massiei'' <small>Lefèvre, 1893</small>: moved to ''Parheminodes'' * ''Chrysochus mouhoti'' <small>Baly, 1864</small>: moved to ''Parheminodes'' * ''Chrysochus nilgiriensis'' <small>Jacoby, 1908</small>:<ref name="Jacoby1908">{{cite book|last=Jacoby|first=M.|year=1908|editor-last=Bingham|editor-first=C. T.|title=Coleoptera. Chrysomelidae. Vol. 1|url=https://archive.org/details/coleopterachryso00jacoiala|series=The Fauna of British India, Including Ceylon and Burma|publisher=Taylor & Francis|place=London}}</ref> moved to ''Parheminodes'' * ''Chrysochus pulcher'' <small>Baly, 1864</small>:<ref name="Baly1864">{{cite book|last=Baly|first=J. S.|year=1864|title=Descriptions of new genera and species of Phytophaga|url=https://books.google.com/books?id=lQkAAAAAQAAJ&pg=PA1|publisher=J.S. Baly|place=Stationer's Hall}}</ref> moved to ''Parheminodes''
==Biology== All species of ''Chryochus'' feed on plants in the Apocynaceae (dogbane) and Asclepiadaceae (milkweed) families. A small mutation has allowed the two North American species, ''C. auratus'' and ''C. cobaltinus'', in particular to feed on the plant species containing cardenolides, while all other species of the genus feed on plant species without cardenolides.<ref name="Jolivet2008">{{cite journal|first1=Pierre|last1=Jolivet|first2=Krishna K.|last2=Verma|year=2008|title=Eumolpinae – a widely distributed and much diversified subfamily of leaf beetles (Coleoptera, Chrysomelidae)|url=http://www.bio-nica.info/biblioteca/jolivet2008eumolpinae.pdf|journal=Terrestrial Arthropod Reviews|volume=1|issue=1|pages=3–37|doi=10.1163/187498308X345424}}</ref>
''Chryochus'' beetles by location differ in their exoskeleton color due to varying factors such as temperature, humidity, diet, and adaptation to predators. For example, ''Chryochus'' larvae as they pupate regulate the chemicals involved in pigment control that depend on the temperature.<ref name=":0" />
== Cultural impact == Naturalist and artist Christopher Marley has used species of ''Chrysochus'' as the artistic medium in his mosaic art pieces.<ref name=":0">{{Cite web |last=Gambino |first=Megan |title=10 Gorgeous Mosaics Made From Real Animal Specimens |url=https://www.smithsonianmag.com/science-nature/10-gorgeous-mosaics-made-from-real-animal-specimens-180954976/ |access-date=2025-10-03 |website=Smithsonian Magazine |language=en}}</ref>
==References== {{Reflist}}
==Further reading== *{{cite journal|last1=Dolgovskaya|first1=M.Y.|last2=Volkovitsh|first2=M.G.|last3=Reznik|first3=S.Y.|last4=Moseyko|first4=A. G.|last5=Milbrath|first5=L. R.|display-authors=3|year=2016|title=Host specificity of Asian ''Chrysochus'' Chevr. in Dej. (Coleoptera, Chrysomelidae: Eumolpinae) and their potential use for biological control of invasive ''Vincetoxicum'' species|journal=Entomological Review|volume=96|issue=7|pages=826–830|doi=10.1134/S0013873816070022|s2cid=41525270}}
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Category:Eumolpinae Category:Chrysochus Category:Chrysomelidae genera Category:Beetles of the United States Category:Beetles of Europe Category:Beetles of Asia Category:Taxa named by Louis Alexandre Auguste Chevrolat