Alurnus Fabricius 1775: 94

Synonomys

Poecilalurnus Jacobson 1899: 247.

Type Species

Alurnus grossus Fabricius.

Diagnosis

Alurnus can be distinguished by following combination of characters:

• the lateral margin of the pronotumpronotum:
  occupies all of dorsal part of the prothorax; in anterior angles or posterior angles there may be a small tubercle or pore with a seta
  and the elytra lacking long, stiff spines
• the head lacking a frontal horn
• the pronotumpronotum:
  occupies all of dorsal part of the prothorax; in anterior angles or posterior angles there may be a small tubercle or pore with a seta
  having a tuft of setae in each angle
• the elytral punctures not being in regular rows
• the elytra having costae or not
• the pronotumpronotum:
  occupies all of dorsal part of the prothorax; in anterior angles or posterior angles there may be a small tubercle or pore with a seta
  being much narrower than the base of the elytra
• the antennae being filiform, with 11-antennomeres, antennomere 3 as long as 4 and 5 combined
• the epipleura of the elytra being setose posteriorly
• the labrumlabrum:
  triangular, joined to the clypeus and the oral orifice
  being depressed anteriorly

Description

Large (16-38 mm); convex; oblong-elongate.

Head: fronsfrons:
upper anterior portion of head capsule above the clypeus
slightly concave; often with sulcus(i) or carina; setose or not.

Antenna: slender, filiform, with 11-antennomeres, extending to at least humerus; antennomere 1 short, thick; 2 no more than subequal in length to 1; 3 at least as long as 4 to 5 combined; 6 to 10 decreasing in length, thinner than preceding, 11 usually longer than 10, rounded or pointed at apex.

Pronotum: highly convex, more so anteriorly; wider than long, widest at base; glabrous or finely pubescent; lateral margin sinuate, bisinuate, or angulate, margined or not; basal margin bisinuate; with tuft of setae in each angle.

Scutellum: cordate (heart-shaped) or cuneiform (wedge-shaped).

Elytron: oblong‑oval, convex; lateral and apical margins smooth, margined or slightly laminate; apices individually rounded; punctures irregular, not in regular rows; some species with distinct costae, others with faint costae, others without costae; sparsely pubescent.

Venter: usually punctate and pubescent.

Distribution

Argentina, Bolivia, Brazil, Colombia, Ecuador, Costa Rica, French Guiana, Guyana, Nicaragua, Panamá, Peru, Suriname, and Venezuela.

World Fauna

Number of species: 23. Key to species: Staines (2013).

Hosts

Aroides sp. (Araceae); Astrocaryum, Bactris, Chamaedorea, Cocos, Elaeis, (Arecaceae).

References

Fabricius, J. C. 1775. Systema entomologiae. Lipsiae. 832 pp.

Jacobson, G. G. 1899. De genere Alurno (Coleoptera, Chrysomelidae). Annuaire du Musée Zoologique de l'Académie Impériale des Sciences St. Pétersbourgh 4:245-256.

Staines, C. L. 2013. A review of the genus Alurnus Fabricius, 1775 (Coleoptera: Chrysomelidae: Cassidinae). Insecta Mundi 0291:1-34.