Stegnocephala hemixantha (Suffrian, 1863)

General description: 

Yellow body; ends of antennae black; the finely and dispersedly punctured pronotum and the elytra iron blue; fine punctures and stripes with smoothly curved, glossy interspaces.

male: yellow on the wide front and side edges of the pronotum

female: yellow only on the front edge

[Translated from the original German in Suffrian, 1863].


S. hemixantha shares the same wide, thickset stature and similar colors with S. cyanoptera, but is easily distinguished by its blue pronotum, which is yellow only along the rims or on the corners. The head is flat with very fine lines on the forehead; the very long frons is edged on top only by an inconspicuous cross-elevation over the antennae bumps. The upper lips are very narrow and sharply and diagonally distended. The surface is very finely and dispersedly punctured, lacquer-glossy bright yellow. Only the jaws are brown. The extended, deeply triangularly indented eyes, widened at the top, are black. The antennae of the male are half as long as the body. The root segment is thin and club-shaped, clearly curved outwards, fully three times longer than wide; the second is knotty, somewhat thinner and four times shorter than the first; the third and fourth are inversely cone-shaped, equally long and almost the same length as the first; the next seven are pressed together and widen out in triangles until the tenth, so that the sixth, seventh and eighth are the widest, and the following two segments gradually become narrower and shorter. The last segment is almost equally wide [as the tenth], and with its blunt protrusion, a little longer. The lower five segments, with the upper half of the fifth, are bright yellow. The upper six segments are black. The antennae of the female are somewhat shorter and narrower in all parts, otherwise [the segments are the same as those of the male]. The pronotum is short and very wide, the greater front half curved in a sphere towards the back, also falling quite steeply at the sides, tightly compressed together over the rectangular front edges and then becoming narrower. The sides are finely edged, converging towards the front in flat arches; the hind corners are short but sharp; the hind edge is wide and shallowly indented on either side, with a short, wide, clearly double-edged mid-tip that somewhat pushes upwards through a saddle-shaped cross-indent; on either side of the mid-tip, in front of the hind edge, lies a deep cross-indent. The surfaces are finely and dispersedly punctured on the outside, punctured somewhat more densely on the sides, and glossy bright iron-blue. In the male, a wide front and side edge; in the female, only the washed-out front edge, are bright yellow. The scutellum rises sharply and diagonally, is triangularly shaped and over half longer than wide. It is pressed down across in front, forming clear front dimples, and cut off abruptly in the back, forming a hind-tip that is just as clear and likewise glossy iron blue. The elytra begin wide but become narrower towards the back, round off short and wide at the back, measure equally long as wide, are pressed down steeply and diagonally along the roots, curve into a hump around the scutellum tip, and from there fall sideways and hindwards in a diagonal curve. The sharply rising shoulder humps meet on the inside with the deeply engraved front end of the fifth puncture-stripe. The side flanks are short and wide, with under-edges deeply pulled downwards. The elytra are strongly pressed together over them. The puncture-stripes are very regular, beginning with front ends deeply indented in grooves, suddenly fainting, and then appearing fine, but clearly running until the tip. The interspaces are wide and flat, punctured finely and sparingly; the outermost interspace is smoothly curved. The color is bright and glossy iron blue; with one of the available females, the color on the shoulder humps, the front seam of the elytra (with interruptions), a hind-tip of the pronotum, and a few random indents on the pronotum approaches brass green. The enveloping edge of the side-flanks is scarredly punctured, dull, and deep blue-black.

There exists a variant:

β. The pronotum and elytra are somewhat copper blue, like those of S. perplexus and cuprascens; characteristic only of one female.

The pygidium is finely punctured in wrinkles, thinly haired, and bright yellow; the undersides and legs are somewhat darker yellow, with pale hips and abdominal rings in the male. The front rim of the prosternum widely extended into a rectangle, with round edges. The mid-field is coarsely punctured, somewhat indented at the back; the hind rim is almost cut off across, with sharp, extended hind corners. The last segment of the male is lightly pressed down across; that of the female forms the normal, round pit.

[Translated from the original German in Suffrian, 1863].


Amazon River (Museum Baly; Ega is the place of origin of variant β). [Translated from Suffrian, 1863].

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith