Calyxochaetus tripilus

Calyxochaetus tripilus species group Diagnosis. The tripilus species group is defined by a long fore tarsomere 1 in males that is 1.5X longer than tarsomere 2 (Figs 20, 22). In all other species of Calyxochaetus, males have a short fore tarsomere 1 (less than or equal to length of fore tarsomere 2). A bare proepimeron in females could be another defining characteristic of this group (female of C. longitarsus sp. nov. is unknown). The shiny, glabrous frons will distinguish males and females of this atypical species group from similar sympycnine genera (e.g., Sympycnus). Remarks. This species group includes C. angustipennis, C. longitarsus sp. nov. and C. tripilus (Van Duzee) and differs from other species of Calyxochaetus since males have an unmodified fore tarsomere 1 and females have a bare proepimeron (at least in C. angustipennis and C. tripilus). However, these species are retained in Calyxochaetus because they share most other characters with the genus, including those of the male genitalia, which are indistinguishable from the other species of the genus.