OCR Text |
Show 1905.] OF PHYTOPHAGOUS COLEOPTERA. 441 O e d io n y ch is il l ig e r i , sp. n . Piceous ; thorax flavous, anterior angles not mucronate ; elytra closely punctured, flavous, a transverse band at the base, emarginate within the shoulders, a narrower band below the middle, and a triangular spot near the apex, dark fulvous or piceous. Var. The posterior elytral markings joined. Length 5-6 millim. Of short and ovately rounded shape ; the head with some deep punctures near the eyes, the vertex piceous, clypeus flavous, eyes well separated, frontal tubercles oblique, rather short; antennas short, fulvous or black, the third, fourth, and fifth joints equal; thorax strongly transverse, more than twice as broad as long, the sides broadly sulcate, rounded in front, the anterior angles not mucronate but thickened, the surface impunctate, flavous; elytra finely and closely punctured, with three transverse dark fulvous bands-the first at the base, nearly extending to the middle and notched at its anterior margin within the shoulders, the second narrower band below the middle and immediately followed by a triangular spot; neither of the bands extends to the lateral or sutural margins, and they are sometimes tinged with an aeneous gloss; metatarsus very short, claw-joint strongly swollen. Hab. Trinidad. I possess four specimens of this species, which is of rather small size, and may be known by the shape of the anterior elytral band, which in all cases is notched at the base, and by the position of the posterior bands, which sometimes form but a single broad one. O e d io n y ch is d is s e p ta Erichs. This is evidently a very variable species in size as well as in the markings of the elytra. Erichson has described two varieties, but I have before me others. In the type the elytra have a broad transverse, nearly black band at the base and another one near the apex ; this latter band is often reduced to an oval spot, or may be absent altogether; in another form which I received from Marcapata, Peru, together with typical specimens, the thorax has two blackish spots at the middle; then there is a third variety, in which the bands are very much broader and only separated by a very narrow transverse flavous band at the middle. No other structural differences are visible, in spite of a very careful examination, nor do the male genitalia of these varieties show any difference whatever. In all the specimens the clypeus, thorax, and the lateral elytral margins remain flavous, the punctuation is extremely fine, the sides of the thorax are nearly straight and are produced anteriorly into a small tooth. 0. signifera Baly and 0. 5-mactilata Jac., likewise from Peru and Bolivia, seem to be nothing but other varieties in which the elytral markings are reduced to spots; they cannot otherwise be |