Some Colorado Species of the Genus Lachnus.

Abstract

Adult Stem Mother .—General color black, with more or less rufous upon the head, thorax and legs; the anterior and nearly all of middle femora, the proximal portion of hind femora, and the basal portions of all tibiae rusty brown, the hind tibiae being black nearly to the base; all tibiae black at extreme base; antennae pale with distal ends of joints 3, 4 and 5 black. The black of the dorsum is mostly dull, but with polished lines running across between each two segments, and a larger polished area on joints 7 and 8. In some specimens there is somewhat of a rufous tinge over most of the dorsum; cornicles black, mammiform, terminating in a slightly projecting nipple; cauda scarcely apparent; vertex prominent and convex. Length of body 4.25; antenna 1.90. Joints of antenna: III, .50; IV, .26; V, .30; VI, .23; hind tibiae, 3.10; beak attaining hind margin of third abdominal segment; sternum and first two abdominal segments rusty brown; head small, convex in front; one sensorium near distal ends of joints 3, 4 and 5, besides the permanent one on joint 5, and sometimes there are two on joint 4. (See Plate X, figures 1–3).