Species tonto Calvert, 1902 [Argia]
The is a large violet species found in the southwest. The face of the male is blue and the top of the head is violet with the typical black markings. The pterothorax is violet and marked with a black middorsal stripe that is less than a forth as width as the pale antehumeral stripe. The humeral stripe is widest anteriorly and narrows posteriorly to form a thin line. The legs are largely black and the wings are clear or occasionally amber. There are 5 and 4 postquadrangular cells in the fore- and hindwing, respectively. The abdomen is violet basally, becoming blue distally. Segments 4-6 each have an apical black spot confluent with an apical ring. Segment 7 is variable with the dorsum either all black or sometimes with a violet triangular spot. Segments 8-10 are blue with a ventrolateral black stripe. The females is similar, but the middorsal thoracic stripe is wider. Abdominal segments 3-5 are variable with a dorsolateral stripe on each side. The posterior lobe of the prothorax is trilobed in the female. The mesostigmal plates bear posterior lobes that are 1/2 the width of the plates themselves and mesepisternal tubercles are absent. Older males and females become pruinescent with age.
Total length: 38-44 mm; abdomen: 30-35 mm; hindwing: 25-29 mm.
Powdered Dancer (A. moesta ) is similar but the middle abdominal segments are mostly dark or white, never violet. Both male and female Sooty Dancers (A. lugens ) has a dark stripe paralleling the middorsal thoracic stripe on each side. The violet form of Springwater Dancer (A. plana ) is smaller and has a broader middorsal thoracic stripe that is as wide as the pale antehumeral area.
Large streams and rivers of arid southwest.
Tonto Dancer is a beautiful large violet Mexican species whose northern range just enters southwestern New Mexico and Arizona. Males are often seen perched on exposed rocks in the middle of the streams or rivers they patrol along.
Southwestern New Mexico and Arizona south to Mexico.