Poplar leaf beetles Chrysomela populi, copyright B. J. Schoenmakers.

Belongs within: Chrysomelini.

Chrysomela is a primarily Holarctic genus of leaf beetles that feed on Betulaceae and Salicaceae. Members of the subgenus Chrysomela have immaculate pale brown or brownish yellow elytra and a uniformly coloured pronotum; the apex of the aedeagus is angulate on each side (Riley et al. 2002).

To make a willow weep
Published 15 March 2015
Pair of spotted willow leaf beetles Chrysomela vigintipunctata, copyright P. V. Romantsov.

As noted in an earlier post, the leaf beetles of the Chrysomelidae include some very attractive representatives. The two individuals in the photo above belong to the widespread genus Chrysomela, many species of which feed on leaves of members of the tree genera Salix, the willows, and Populus, the poplars. Some species can become numerous enough on their hosts to cause extensive defoliation, and the cottonwood leaf beetle Chrysomela scripta is regarded as a serious pest of trees such as the cottonwood Populus deltoides.

Mating pair of Chrysomela populi, copyright Beentree.

Chrysomela beetles that feed on willows are able to sequester salicin from the willow’s leave and use it to secrete a defensive compound of their own, salicylaldehyde. In one European species, Chrysomela lapponica, distinct populations have been identified that feed respectively on willow or birch leaves. Experimental studies have shown that the birch- and willow-feeding populations are largely reproductively isolated from each other: either their inter-fertility is reduced, or hybrid larvae that differ in feeding preference from their mother will be laid on the wrong host tree and be unable to survive. As such, the populations can be recognised as either in the process of diverging into separate species, or as already distinct cryptic species. As birch does not contain salicin, birch-feeding C. lapponica do not produce the salicylaldehyde found in willow-feeding populations, and birch-feeders fed on willow leaves are unable to utilise salicin (Kirsch et al. 2011).

Female Chrysomela lapponica ovipositing on birch leaf, copyright Juergen Gross. As well as the variation in host plant described above, members of this species also vary widely in coloration, from red and black as in the photo to entirely black in some individuals.

As willow is most likely the ancestral food type for C. lapponica, how did some populations make the change to feeding on birch despite losing a significant factor in their own defenses by doing so? One possibility that has been suggested is that the change happened not despite the loss of salicylaldehyde, but because of it (Gross et al. 2004). While the salicylaldehyde acts as an effective defense against generalist predators, some specialist predators and parasitoids of the beetles seem to be directly attracted to it, using it as a marker to track down their target. Pressure from this angle might favour the spread of a population that does not produce the alluring salicylaldehyde.

Systematics of Chrysomela

Characters (from Riley et al. 2002): Coronal suture visible, usually indicated by shallow mesal impression; antennal insertions widely separated; maxilla with terminal palpomere apically attenuate; front coxae transverse, procoxal cavities open behind; elytral punctures completely confused or arranged in very poorly defined rows; if substriate, rows closely spaced and therefore numbering more than nine; tarsal formula 5-5-5, pseudotetramerous, with penultimate tarsomere minute; tarsal claws simple

<==Chrysomela Linnaeus 1758 (nom. cons.)L58
|--C. (Chrysomela) (see below for synonymy)RC02
| |--C. (C.) aenea Linnaeus 1758L58 [=Lina aeneaB66]
| |--C. (C.) collaris Linnaeus 1758L58 [=Melasoma collarisC01; incl. M. collaris var. dauricaC01]
| |--C. (C.) crotchi Brown 1956RC02
| |--‘Lina’ formosana Bates 1866B66
| |--C. (C.) graminis Linnaeus 1758G20, L58
| |--C. (C.) invicta Brown 1956RC02
| |--C. (C.) lapponica Linnaeus 1758L58 [=Lina lapponicaF89, Melasoma lapponicaC01]
| |--C. (C.) populi Linnaeus 1758G20, L58 [=Lina populiAL37, Melasoma populiC01]
| `--‘Melasoma’ tremulaeR13
|--C. (Doryphora)G20
| |--‘Doryphora’ decemlineataR13
| `--C. (D.) punctatissimaG20
|--C. (Macrolina Motschulsky 1860) (see below for synonymy)RC02
`--C. (Pachylina Medvedev & Chernov 1969)RC02
`--C. (P.) blaisdelli Van Dyke 1938RC02

Chrysomela incertae sedis:
C. aequinoctialis Linnaeus 1758L58
C. aestuans Linnaeus 1758L58
C. alni Linnaeus 1758L58
C. americana Linnaeus 1758L58
C. armoraciae Linnaeus 1758L58
C. asparagi Linnaeus 1758L58
C. aurichalceaC01
C. bankiiR26
C. betulae Linnaeus 1758L58
C. bipunctata Linnaeus 1758L58
C. boleti Linnaeus 1758L58
C. bothnica Linnaeus 1758L58
C. cacaliaeR26
C. caprea Linnaeus 1758L58
C. carbonata Boisduval 1835B35
C. ceramboides Linnaeus 1758L58
C. cerasi Linnaeus 1758L58
C. cerealisC01
C. cervina Linnaeus 1758L58
C. chloris Lucas 1847E12
C. chrysocephala Linnaeus 1758L58
C. coccinea Linnaeus 1758L58
C. cochleariaeR26
C. confluensFKW93
C. cordigera Linnaeus 1758L58
C. coriariaL02
C. coryli Linnaeus 1758L58
C. crassipes Lucas 1847E12
C. curtisiiB35
C. cyanella Linnaeus 1758L58
C. decemmaculata Linnaeus 1758L58
C. decempunctata Linnaeus 1758L58
C. distans Csiki 1901C01
C. elongata Linnaeus 1758L58
C. erythrocephala Linnaeus 1758L58
C. erythromera Lucas 1847E12
C. exsoleta Linnaeus 1758L58
C. fastuosaC01
C. gaubilii Lucas 1847E12
C. goettingensis Linnaeus 1758L58
C. grossaR26
C. guttifera [incl. C. guttifera var. nigrogemmata]C01
C. gypsophilaeC01
C. haemoptera Linnaeus 1758L58
C. haemorrhoidalis Linnaeus 1758L58
C. helxines Linnaeus 1758L58
C. hemisphaerica Linnaeus 1758L58
C. holsatica Linnaeus 1758L58
C. hottentotaR26
C. hyoscyami Linnaeus 1758L58
C. hypochaeridis Linnaeus 1758L58
C. inda Linnaeus 1758L58
C. limbata [incl. C. limbata var. hochhuthi]C01
C. macleayi [incl. C. litura]B35
C. maculicollis d’Urville in Boisduval 1835B35
C. marginata Linnaeus 1758L58
C. marginella Linnaeus 1758L58
C. melanocephalaR26
C. melanopus Linnaeus 1758L58
C. merdigera Linnaeus 1758L58
C. minuta Linnaeus 1758L58
C. moraei Linnaeus 1758L58
C. muralis Csiki 1901C01
C. murina Linnaeus 1758L58
C. nemorum Linnaeus 1758L58
C. nitida Linnaeus 1758L58
C. nitidipennis Dejean in Boisduval 1835B35
C. nitidula Linnaeus 1758L58
C. nymphaeae Linnaeus 1758L58
C. obscura Linnaeus 1758L58
C. occidentalis Linnaeus 1758L58
C. oceanica Boisduval 1835B35
C. oleracea Linnaeus 1758L58
C. padi Linnaeus 1758L58
C. pallida Linnaeus 1758L58
C. perforataC01
C. philadelphica Linnaeus 1758L58
C. pini Linnaeus 1758L58
C. polita Linnaeus 1758L58
C. polygoni Linnaeus 1758L58
C. quadrimaculata Linnaeus 1758L58
C. quadripunctata Linnaeus 1758L58
C. ruficeps MacLeay in Boisduval 1835B35
C. rufilabrisC01
C. rufipes Linnaeus 1758L58
C. rugosaL02
C. sacra Linnaeus 1758L58
C. salicivoraxF92
C. salviaeC01
C. sanguinolenta Linnaeus 1758L58
C. sapphirusB35
C. scriptaFKW93
C. sericea Linnaeus 1758L58
C. sexpunctata Linnaeus 1758L58
C. s-litera Linnaeus 1758L58
C. staphylaea Linnaeus 1758L58
C. stevensiJ89
C. sulphurea Linnaeus 1758L58
C. tanaceti Linnaeus 1758L58
C. tardaC01
C. teichophila Csiki 1901C01
C. tenebricosaL02
C. tridentata Linnaeus 1758L58
C. trilineata d’Urville in Boisduval 1835B35
C. undecimpunctata Linnaeus 1758L58
C. urbana Csiki 1901C01
C. variansR13
C. viminalis Linnaeus 1758L58
C. violaceaR26
C. vitellinae Linnaeus 1758L58
C. vulgatissima Linnaeus 1758L58

Chrysomela Linnaeus 1758 (Chrysomela) [incl. Gymnota Gistel 1847 non Gistel 1834, Lina Dejean 1836, Melasoma Stephens 1831, Melosoma (l. c.)]RC02

Chrysomela (Macrolina Motschulsky 1860) [incl. Microdera Stephens 1839 non Eschshcoltz 1831, Microlina Lopatin 1977 (nom. inv.), Strickerus Lucas 1920]RC02

*Type species of generic name indicated


[AL37] André, M., & É. Lamy. 1937. Les Idées actuelles sur la Phylogénie des Acariens. Published by the author: Paris.

[B66] Bates, H. W. 1866. On a collection of Coleoptera from Formosa sent home by R. Swinhoe, Esq., H. B. M. Consul, Formosa. Proceedings of the Zoological Society of London 1866: 339–355.

[B35] Boisduval, J. B. 1835. Voyage de Découvertes de l’Astrolabe. Exécuté par ordre du Roi, pendant les années 1826–1827–1828–1829, sous le commandement de M. J. Dumont d’Urville. Faune entomologique de l’océan Pacifique, avec l’illustration des insectes nouveaux recueillis pendant le voyage vol. 2. Coléoptères et autres ordres. J. Tastu: Paris.

[C01] Csiki, E. 1901. Bogarak [Coleopteren]. In: Horváth, G. (ed.) Zichy Jenő Gróf Harmadik Ázsiai Utazása [Dritte Asiatische Forschungsreise des Grafen Eugen Zichy] vol. 2. Zichy Jenő Gróf Harmadik Ázsiai Utazásának Állattani Eredményei [Zoologische Ergebnisse der Dritten Asiatischen Forschungsreise des Grafen Eugen Zichy] pp. 75–120. Victor Hornyánszky: Budapest, and Karl W. Hierseman: Leipzig.

[E12] Evenhuis, N. L. 2012. Publication and dating of the Exploration Scientifique de l’Algérie: Histoire Naturelle des Animaux Articulés (1846–1849) by Pierre Hippolyte Lucas. Zootaxa 3448: 1–61.

[F89] Fairmaire, L. 1889. Coléoptères de l’intérieur de la Chine. 5e partie. Annales de la Société Entomologique de France, 6e série 9: 5–84.

[F92] Fan Z. 1992. Key to the Common Flies of China 2nd ed. Science Press: Beijing.

[FKW93] Floate, K. D., M. J. C. Kearsley & T. G. Whitham. 1993. Elevated herbivory in plant hybrid zones: Chrysomela confluens, Populus and phenological sinks. Ecology 74 (7): 2056–2065.

[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.

Gross, J., N. E. Fatouros, S. Neuvonen & M. Hilker. 2004. The importance of specialist natural enemies for Chrysomela lapponica in pioneering a new host plant. Ecological Entomology 29: 584–593.

[J89] Jacoby, M. 1889. Viaggio di Leonardo Fea in Birmania e regioni vicine. XVII.—List of the phytophagous Coleoptera obtained by Signor L. Fea at Burmah and Tenasserim, with descriptions of the new species. Annali del Museo Civico di Storia Naturale di Genova, Serie 2a, 7: 147–237.

Kirsch, R., H. Vogel, A. Muck, K. Reichwald, J. M. Pasteels & W. Boland. 2011. Host plant shifts affect a major defense enzyme in Chrysomela lapponica. Proceedings of the National Academy of Sciences of the USA 108 (12): 4897–4901.

[L02] Latreille, P. A. 1802. Histoire Naturelle, générale et particulière des crustacés et des insectes vol. 3. Familles naturelles des genres. F. Dufart: Paris.

[L58] Linnaeus, C. 1758. Systema Naturae per Regna Tria Naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Laurentii Salvii: Holmiae.

[R13] Reuter, O. M. 1913. Lebensgewohnheiten und Instinkte der Insekten bis zum Erwachen der sozialen Instinkte. R. Friedländer & Sohn: Berlin.

[RC02] Riley, E. G., S. M. Clark, R. W. Flowers & A. J. Gilbert. 2002. Chrysomelidae Latreille 1802. In: Arnett, R. H., Jr, M. C. Thomas, P. E. Skelley & J. H. Frank (eds) American Beetles vol. 2. Polyphaga: Scarabaeoidea through Curculionoidea pp. 617–691. CRC Press.

[R26] Risso, A. 1826. Histoire naturelle des principales productions de l’Europe méridionale et particulièrement de celles des environs de Nice et des Alpes maritimes vol. 5. F.-G. Levrault: Paris.

Leave a comment

Your email address will not be published. Required fields are marked *