Jeweled Weevils

Curculionidae, Leptosinae, Entimini, Entimus.

These are fairly large (BL 12—40 mm), spectacularly colored weevils (fig. 9.16f), with the black elytra much wider than the prothorax and spangled with numerous brilliant green, gold, or blue scales in longitudinal rows (gray-white hairs replace the scales in one species), which gives them a spectral sparkle, like emeralds or sapphires. There is also a green midline stripe on the prothorax, while the remainder of the body and legs are flecked with tiny green scales. On the elytra, the scales are situated in pits or other depressions. Many species also have granules or tubercles on the dorsal surface. All are winged, the beak is short and robust, and the legs are hairy, especially in males.

Because of their lovely and bright colors, they have been used to make jewelry like other regional beetles. In his day, Cowan (1865) related,

At Rio Janeiro, the brilliant Diamond Beetle, Entimis nobilis, is in great request for broches for gentlemen, and ten piasters are often paid for a single specimen. In this city many owners send their slaves out to catch insects, so that now the rarest and most brilliant species are to be had at a comparatively trifling sum. For these splendid insects there is a general demand; and their wing cases are now sought for the purpose of adorning the ladies of Europe—a fashion, it is said, which threatens the entire extinction of this beautiful tribe.

These weevils have survived and are still prized items in tourist curio displays sold in Rio de Janeiro, Bogotá, and Lima.

The five species are exclusively Neotropical and distributed throughout Central and South America, except Chile and southern Argentina (Vaurie 1951). They are typically lowland or coastal, preferring humid climates.

Most of what is known regarding their biology comes from a work by Bruch (1932) on Entimus nobilis. He found it breeding in the tubercular roots of Stigma-phyllon littorale (Malpighiaceae) along the banks of the Ríos Plata and Paraná. Adults feed on the leaves of this plant, although they are recorded also on the leaves of bombacaceous trees (Ceiba, Chorisia, Bom-box) (Bruch 1932).

The female E. nobilis doubles the leaves of its host, sticking the edges together with a viscous substance, to form a cupola for its eggs. After hatching, the young larvae drop to the ground and burrow through the soil in search of tubers in which to complete their development. The mature C-shaped larvae are strongly wrinkled.

References

Bruch, C. 1932. Metamorfosis de Entimus nobilis Oliv. (Coleopt., Curculionidae). Rev. Entomol. 2: 179-185. Cowan, F. 1865. Curious facts in the history of insects; including spiders and scorpions. Lip-pincott, Philadelphia. Vaurie, P. 1951. Revision of the genus Entimus with notes on other genera of Entimini (Coleoptera: Curculionidae). Rev. Chilena Entomol. 1: 147-170.

0 0

Post a comment