Hagen in Selys, 1858
Species compositus Hagen in Selys, 1858 [Erpetogomphus]
Syn Erpetogomphus coluber Williamson and
This is one of the more distinctive of the six ringtail species in the region. Its face is nearly white with only a few dark markings. The vertex is dark brown, often with a pale median spot extending posteriorly from the median ocell us. The thorax is pale green, more so in the front. The brown middorsal stripe is well-defined and widens anteriorly to the collar. The antehumeral stripe widens early on and is connected basally but free at its upper end. The humeral stripe extends posteroventrally for some distance, but not as far as to connect with the midlateral stripe. The pale areas between these stripes are so pale that they often appear white. The hind femora are light pale green with the outer surfaces black and the tibiae mostly black. The wings are clear with only a slight wash of yellow at their bases. The abdomen is pale gray, almost appearing white, for much of its length (segments 1-6), and strongly marked with black rings on the middle segments. Segment 7 in males, is white dorsally on the anterior half becoming yellowish posteriorly. The remaining segments are yellowish brown and generally darker in females. This is the only ringtail species in the region where the male cerci are not strongly angulate.
Total length: 46-55 mm; abdomen: 31-39 mm; hindwing: 26-32 mm.
Its white face and pale coloration make it distinctive among the other ringtail species in our region. Sulphur-tipped (Gomphus militaris ) and Plains (G. externus ) Clubtails have no abdominal rings.
Desert streams, creeks and irrigation ditches with wide sandy or rocky margins.
This species is not usually common in the region, which is on the eastern edge of its range, but has been called one of the most conspicuous clubtails along desert streams and irrigation ditches in the southwestern United States. Although presently restricted to these desert-like streams, this species once ranged as far east as Dallas, Texas. Although often seen perched on sandbars of streams, it is readily found in shady, more protected areas in the late afternoon. Females lay eggs while hovering motionless over water and tapping their abdomens to the water surface.
Western U.S. and northern Mexico.