Colobopsis impressa

Distribution based on Regional Taxon Lists
Nearctic Region: United States.



Nomenclature

 *  impressus. Colobopsis impressa Roger, 1863a: 160 (w.) U.S.A. Mayr, 1886d: 423 (s.q.); Emery, 1893i: 681 (m.). Combination in Camponotus (Colobopsis): Emery, 1889b: 517.

Worker
Wheeler (1904) - Major Length, 4.3-4.6 mm.

Head subcylindrical, from above rectangular, but little longer than broad, sides parallel, occipital border convex, anterior truncated surface concave, its edge distinctly carinate along the sides, but rounded above in the clypeal and adjacent regions. Mandibles small, with flattened lower surfaces, 4-toothed, with a short toothless proximal portion to the blade. Clypeus on the truncated surface twice as long as broad, slightly broader above, extending onto the dorsal surface of the head as a transversely oblong piece about three times as broad as long. There is a distinct median keel running the full length of the clypeus. Frontal carina:: far apart, distinctly converging in front, somewhat convex externally. Eyes moderate, flattened, their anterior orbits about a third the distance from the posterior border of the head to the tips of the mandibles. Antennal scapes curved, slender at the base, gradually enlarging towards their tips, which extend beyond the posterior corners of the head to a distance about equal to their transverse diameter. All the funicular joints except the first, subequal, a little longer than broad, first joint nearly as long as the second and third together. Thorax robust, pronotum broader than fong, very convex and rounded, and forming a sphere with the mesonotum. Mesoepinotal constriction broad and pronounced. Epinotum with short convex basal, and longer, somewhat concave declivous surfaces, the angle between the two being rather blunt. Petiole low, convex and rounded in front and above, flattened behind, the posterior dorsal edge of the node being distinctly impressed in the middle, but not excised or emarginate. Gaster rather broad, flattened dorso-ventrally. Legs short, femora compressed, anterior pair distinctly dilated.

Mandibles opaque, finely punctate, longitudinally and obscurely rugose. Anterior two-fifths of head subopaque, coarsely and rather regularly reticulate-rugose, the spaces enclosed by the rugae being densely punctate. On the front and cheeks the sculpture passes over into shallow umbilicately punctate foveolae. Behind this region there is a narrow uniformly punctate zone both on the cheeks and front. Posterior portion of head and remainder of body shining, delicately but distinctly shagreened.

Cheeks and anterior dorsal surface of head with short, erect, obtuse, brown hairs. There are a few erect hairs on the vertex and on the gastric segments, especially along their posterior edges, and a few at the tips of the antennal scapes and femora. The legs are sparsely covered with minute, appressed white hairs.

Thorax and appendages dark brown, the former with yellowish sutures, gaster and posterior two-thirds of head black; anterior third of head light yellowish brown. Mandibular teeth black.

Minor Length, 3.5-4.5 mm.

Head but little longer than broad, a little broader behind than in front, cheeks convex. Mandibles small, 4- to 5-toothed, when closed their external margins form a straight line at right angles to the long axis of the head. Clypeus nearly square, obscurely keeled. Frontal carinre converging in front. Antennae more slender and proportionally longer than in the soldier, surpassing the posterior corners of the head by about one third their length. Thorax and petiole resembling the corresponding parts of the soldier. Gaster proportionally smaller and more pointed.

Body and appendages shining, distinctly shagreened, the head and thorax more coarsely than the gaster; the cheeks and upper surface of the head also with scattered punctures.

Cheeks and legs covered with delicate, appressed, white hairs. Clypeus, front, vertex, tips of antennre and femora and the gastric segments with a few scattered and longer brown hairs.

Dark brown, head and gaster black, mandibles yellow, anterior portions of cheeks and clypeus, antennae and legs, pale brown.

Queen
Wheeler (1904) - Length, 6 mm.

Head like that of the soldier but less robust. Petiole as in the soldier, with a low, thick, four-cornered node, which is broader than high.

Sculpture and pilosity as in the soldier.

Ferruginous, in part yellowish red. Mesonotum, except for two yellow longitudinal lines, the scutellum and the middle of the epinotum, light brown; gaster brownish black, the anterior two-thirds of the first and second segments yellow.

Male
Wheeler (1904) - According to Emery "very similar to the South European C. truncates in form and coloration, but somewhat smaller (4-4.5 mm.); in other respects hardly distinguishable.