Oncid ID: Tool for Diagnosing Adult Twig Girdlers (Cerambycidae: Lamiinae: Onciderini)
Home   ¦   Twig Girdlers   ¦   Key to Genera   ¦   Genus Fact Sheets   ¦   Gallery   ¦   Morphological Atlas   ¦   Glossary   ¦   References   ¦   About

Previous Genus       Next Genus

Genus: Ischiosioma

Diagnostic Features
  • Description: Elongate-oblong, moderate to large-sized, ranging from about 14–23 mm in length. Integument generally dark brown with whitish, ferrugineous, and ochraceous pubescence. Head with frons subquadrate, about as wide as width of two lower eye lobes. Eyes with lower lobes oblong. Genae elongate, distinctly shorter than lower eye lobes. Antennal tubercles prominent, widely separated; tubercles not armed at apex; antennae about as long as overall body length, or as much as 1 1/3 times as long; scape gradually expanded to apex, about as long as antennomere IV; antennomere III curved, longer than scape and antennomere IV. Pronotum transverse, roughly cylindrical to conical, wider at base, without lateral tubercles. Elytra with sides roughly parallel; elytral apices individually rounded; elytra generally uniform in coloration or speckled, or with distinct maculae; base of elytra without prominent tubercles at humeri. Basal 1/3 of elytra with dense punctation, surface coarsely punctate to granulate-punctate. Procoxae without projection. Mesosternal process with apex subtruncate to feebly 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: large eyes; subquadrate frons; gradually expanded scape; pronotum distinctly narrower than elytral humeri, without lateral tubercles; and elytra with sides roughly parallel.

  • Similar genus/genera: superficially resembles Cordites and Ischiocentra.
Geographic Distribution
  • South America (Brazil)
Host Plants/Trees
  • Unknown
Girdling Behavior
  • Unknown

The genus Ischiosioma currently contains two species:
  Ischiosioma albata Martins & Galileo, 1990 [holotype specimen, ♀]
  Ischiosioma obliquata Martins & Galileo, 1990 [holotype specimen, ♀]

Generic Synonymies
  • None
Selected References

Ischiosioma obliquata
holotype specimen, ♀
© E.H. Nearns


© 2011-2015 Nearns, E.H., Lord, N.P., and K.B. Miller
The University of New Mexico and Center for Plant Health Science and Technology, USDA, APHIS, PPQ.