March 2026: Since the original publication of this tool, Trachysomus dromedarius (Voet, 1778) was found to be nomina nuda, and Trachysomus verrucosus (Olivier, 1795) is the valid name for this species (Nearns and Tavakilian 2015Nearns and Tavakilian 2015:
Nearns EH, Tavakilian GL. 2015. Seven new species of Oncideres Lacordaire, 1830 (Coleoptera: Cerambycidae: Lamiinae: Onciderini) from South America, with notes on additional taxa. Arquivos de Zoologia. 46(7):87-113.). This taxonomic change is reflected in "Included Species". Other sections in this fact sheet have not been edited to account for this taxonomic change.
Elongate-ovate, robust, moderate to large-sized, ranging from about 15–26 mm in length. Integument generally dark brown or ferrugineous with whitish, ferrugineous, black, and ochraceous pubescence. Head with frons subquadrate to transverse, about as wide as width of four lower eye lobes. Eyes with lower lobes ovate-oblong. Genae subquadrate to elongate, variable in height, from distinctly shorter to distinctly taller than lower eye lobes. Antennal tubercles prominent, widely separated; tubercles not armed at apex or armed with a small projection. Antennae distinctly shorter than overall body length, or about as long; scape clavate, about as long as antennomere IV; antennomere III nearly straight or curved, longer than scape and antennomere IV. Pronotum subquadrate to transverse, roughly cylindrical to conical, wider at base, with or without lateral tubercles. Elytra with sides roughly parallel to attenuate; elytral apices individually rounded; elytra generally uniform in coloration or speckled, or with distinct maculae; base of elytra with two or more prominent, irregularly shaped, rough, blunt tubercles at humeri. Basal 1/3 of elytra with sparse to dense punctation, surface coarsely punctate to granulate-punctate. Procoxae without projection. Mesosternal process with apex subtruncate to deeply emarginate. Metafemora moderate to short in length, about 1/3–1/4 as long as elytra.
The combination of the following characters will help to distinguish this genus: distinctly robust form; eyes widely separated; and base of elytra with two or more prominent, irregularly shaped, rough, blunt tubercles at humeri.
The genus Trachysomus is distinct among Onciderini and not easily confused with other genera. However, Paratrachysomus is superficially similar and Cydros is also roughly sculptured but is smaller and less robust.
Central America (Mexico, Nicaragua to Panama); South America (Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Trinidad & Tobago, Venezuela)
Achatocarpaceae (Achatocarpus praecox); Annonaceae (Annona emarginata); Boraginaceae (Cordia americana); Myrtaceae (Psidium guajava [guava]); Nyctaginaceae (Pisonia zapallo); Polygonaceae (Triplaris cumingiana, T. weigeltiana)
This genus is suspected to girdle branches of trees.
The genus Trachysomus currently contains 17 species: T. apipunga Martins and Galileo, 2008Martins and Galileo, 2008:
Martins UR, Galileo MHM. 2008. Novas especies de Onciderini (Coleoptera, Cerambycidae, Lamiinae) da Bolivia. Papeis Avulsos de Zoologia. 48(4):27–31.; T. arriagadai Galileo and Martins, 1991Galileo and Martins, 1991:
Galileo, MHM, Martins UR. 1991. Nova especie do genero Trachysomus A.-Serville, 1835 do Paraguai (Coleoptera, Cerambycidae, Lamiinae, Onciderini). Iheringia, Série Zoologia, Porto Alegre. 71:129–132.; T. buquetii Thomson, 1858Thomson, 1858:
Thomson J. 1858. Synopsis du genre Trachysomus. Archives Entomologiques. 1:384–387.; T. camelus Buquet, 1852; T. cavigibba Martins, 1975Martins, 1975:
Martins UR. 1975. Notas e descricoes em Onciderini (Coleoptera, Cerambycidae). Papeis Avulsos de Zoologia. 29(10):65–70.; T. clarkei Martins and Galileo, 2009; T. fragifer (Kirby, 1818); T. gibbosus Buquet, 1852; T. hydaspes Dillon and Dillon, 1946Dillon and Dillon, 1946:
Dillon LS, Dillon ES. 1946. The tribe Onciderini (Coleoptera: Cerambycidae) Part II. Reading, Scientific Publications, Reading Public Museum and Art Gallery, Number 6. 189–413 pp.; T. luederwaldti Martins, 1975Martins, 1975:
Martins UR. 1975. Notas e descricoes em Onciderini (Coleoptera, Cerambycidae). Papeis Avulsos de Zoologia. 29(10):65–70.; T. mexicanus Dillon and Dillon, 1946Dillon and Dillon, 1946:
Dillon LS, Dillon ES. 1946. The tribe Onciderini (Coleoptera: Cerambycidae) Part II. Reading, Scientific Publications, Reading Public Museum and Art Gallery, Number 6. 189–413 pp.; T. peregrinus Thomson, 1858Thomson, 1858:
Thomson J. 1858. Synopsis du genre Trachysomus. Archives Entomologiques. 1:384–387.; T. santarensis Bates, 1865Bates, 1865:
Bates HW. 1865. Contributions to an insect fauna of the Amazon Valley. Coleoptera: Longicornes. The Annals and Magazine of Natural History 3(15):213–225, 382–394; 3(16):101–113, 167–182, 308–314.; T. surdus Dillon and Dillon, 1946Dillon and Dillon, 1946:
Dillon LS, Dillon ES. 1946. The tribe Onciderini (Coleoptera: Cerambycidae) Part II. Reading, Scientific Publications, Reading Public Museum and Art Gallery, Number 6. 189–413 pp.; T. thomsoni Aurivillius, 1923; T. verrucosus (Olivier, 1795); T. wappesi Martins and Galileo, 2009.
More species images are available in the Gallery.
Trachysomus Audinet-Serville, 1835Audinet-Serville, 1835:
Audinet-Serville JG. 1835. Nouvelle classification de la famille des longicornes (suite et fin). Annales de la Société Entomologique de France. 4(1):5–100.
subtribe: Onciderina
type species: Lamia fragifera Kirby, 1818
Audinet-Serville (1835)Audinet-Serville (1835):
Audinet-Serville JG. 1835. Nouvelle classification de la famille des longicornes (suite et fin). Annales de la Société Entomologique de France. 4(1):5–100., Bates (1865)Bates (1865):
Bates HW. 1865. Contributions to an insect fauna of the Amazon Valley. Coleoptera: Longicornes. The Annals and Magazine of Natural History 3(15):213–225, 382–394; 3(16):101–113, 167–182, 308–314., Bezark and Monné (2013)Bezark and Monné (2013):
Bezark LG, Monné MA. 2013. Checklist of the Oxypeltidae, Vesperidae, Disteniidae and Cerambycidae, (Coleoptera) of the Western Hemisphere., Buquet (1859)Buquet (1859):
Buquet L. 1859. Notice monographique sur un genre nouveau de coleopteres de la famille des cerambycides (longicornes). Arcana Naturae. 1:45–49., Dillon and Dillon (1946)Dillon and Dillon (1946):
Dillon LS, Dillon ES. 1946. The tribe Onciderini (Coleoptera: Cerambycidae) Part II. Reading, Scientific Publications, Reading Public Museum and Art Gallery, Number 6. 189–413 pp., Galileo and Martins (1991)Galileo and Martins (1991):
Galileo, MHM, Martins UR. 1991. Nova especie do genero Trachysomus A.-Serville, 1835 do Paraguai (Coleoptera, Cerambycidae, Lamiinae, Onciderini). Iheringia, Série Zoologia, Porto Alegre. 71:129–132., Martins (1975)Martins (1975):
Martins UR. 1975. Notas e descricoes em Onciderini (Coleoptera, Cerambycidae). Papeis Avulsos de Zoologia. 29(10):65–70., Martins and Galileo (2008)Martins and Galileo (2008):
Martins UR, Galileo MHM. 2008. Novas especies de Onciderini (Coleoptera, Cerambycidae, Lamiinae) da Bolivia. Papeis Avulsos de Zoologia. 48(4):27–31., Martins and Galileo (2009a)Martins and Galileo (2009a):
Martins UR, Galileo MHM. 2009a. Onciderini (Coleoptera, Cerambycidae, Lamiinae): notas, descricoes, novas combinacoes e chave para grupo de especies de Trachysomus. Papeis Avulsos de Zoologia. 49(13):151–161., Monné (2005)Monné (2005):
Monné MA. 2005. Catalogue of the Cerambycidae (Coleoptera) of the Neotropical Region. Part II. Subfamily Lamiinae. Zootaxa. 1023:1–759., Nearns and Tavakilian (2015)Nearns and Tavakilian (2015):
Nearns EH, Tavakilian G-L. 2015. Seven new species of Oncideres Lacordaire, 1830 (Coleoptera: Cerambycidae: Lamiinae: Onciderini) from South America, with notes on additional taxa. Arquivos de Zoologia. 46(7):87-113., Thomson (1858)Thomson (1858):
Thomson J. 1858. Synopsis du genre Trachysomus. Archives Entomologiques. 1:384–387., Wappes et al. (2009)Wappes et al. (2009):
Wappes JE, Ledezma Arias J, Nearns EH. 2009. List of Coleoptera holotypes in Museo de Historia Natural, Noel Kempff Mercado, Universidad Autonoma "Gabriel Rene Moreno," Santa Cruz de la Sierra, Bolivia. Insecta Mundi. 081:1–8.
