Species barretti Calvert, 1902 [Argia]
The face of the male is bright blue and there are large pale postocular spots broadly confluent with compound eyes. There is a distinct thin blue occipital bar present between the postoccular spots which is boradly divided medially appearing as two smaller spots. The pterothorax is blue with a broad black middorsal stripe half as wide as the blue antehumeral stripe next to it. The humeral stripe is straight, but narrowing posteriorly. The legs are solid black exteriorly and pale medially. There are usually 5 and 4 postquadrangular cells in the fore- and hindwing, respectively. The abdomen is predominately blue dorsally with black ventrolateral stripes widening posteriorly and becoming more pronounced on segments 6 and 7. The ventrolateral stripes form confluent rings posteriorly around each segment. Segment 7 is almost entirely black dorsally and segments 8-10 are blue dorsally with only a narrow black stripe laterally. The cerci are only 2/3 the length of the paraprocts and they are distinctly bifid in dorsal view. The paraprocts are bifid with the upper branch directed dorsally and the lower branch directed posteriorly; the angle between the two approximately 90o0. The female color pattern is similar to the male, but paler, often with tan or light brown colors replacing blues. The dark thoracic markings are less extensive. The humeral stripe is diffuse brown for the lower half of the suture and black in its upper half. The mesostigmal plates in dorsal view possess large posterior lobes that are less than half the width of the plate itself. Mesepisternal tubercles are present, but generally small and reduced in size. The legs are pale with with less extensive black markings than in the male.
Total length: 38-43 mm; abdomen: 31-34 mm; hindwing: 22-25 mm.
Comanche Dancer is one of the largest and most easily recognized bright blue damselflies in the region. Blue-fronted Dancer (A. apicalis ) is smaller has has a very narrow middorsal thoracic stripe. Paiute Dancer (A. alberta ) is much smaller and has a strongly forked humeral stripe. Big Bluet (Enallagma durum ) is the same size, but a paler blue with black dorsal markings on the abdomen in the shape of spear points.
Rivers and streams.
This species has a primarily Mexican distribution, occurring in the states of Nuevo Leon and Tamaulipas, northward to the Hill Country of Texas where it can be a dominant species on wide rocky streams. Females lay eggs in tandem on floating debris at the rivers edge. Details of its reproductive behavior are unknown.
Texas south to San Luis Potosi and Tamaulipas, Mexico.