United States and Canada
The eyes are brown above, fading to pale green below. The face and head are bright red with the area posterior to the ocelli black. The middorsal stripe and are carina black and the antehumer al stripe is orange. A dark humeral stripe covers only the posterior 2/3 of respective suture. The remaining pterothorax varies from orange to black laterally. A black stripe is present only on the anterior mesepimeron. The metapleural suture and venter of the pterothorax vary from tan to black. The abdominal segments 1-2 are variable, but generally with orange dorsally. The rest of the abdomen is black with narrow pale apical bands on segments 3-9. Segments 1-6 are pale ventrolaterally. The cerci are deeply bifurcated. The head and body are tan in color with only thin black markings present. Middle lobe of pronotum with black spot on each side at posterior margin. Abdomen darker dorsally with dark subapical bands and lateral stripes on middle segments. Segments 8-10 are pale laterally.

Size: Total length: 30-35 mm; abdomen: 24-29 mm; hindwing: 16-18 mm.

Similar Species (south-central US): Male and female Orange-striped Threadtail (Protoneura cara) have more black on the thorax than orange. Male Coral-fronted Threadtail (N. aaroni) lacks orange dorsally on abdominal segments 2-3. Female Coral-fronted Threadtail is nearly identical to Amelia's Threadtail, but Amelia's Threadtail is generally paler on the thorax and abdomen, especially the terminal segments and Coral-fronted Threadtail lacks the posterior markings on the middle lob of the pronotum. Orange Bluet (Enallagma signatum) is similar but the orange on the face and thorax is not as bright or extensive.

Habitat: Prefers protected, well-shaded areas of slow-moving rivers and streams with emergent or floating vegetation, detritus or debris.

Natural History: Amelia's Threadtail is found throughout Middle America. It was only recently reported from the United States, at the southern border in Hidalgo County, Texas. It is found among floating debris in shady areas along the Rio Grande. Adults also perch on emergent vegetation of clear lakes in the immediate vicinity of stream outlets. Males are variable in the degree of black on the head, thorax and first three abdominal segments and I have seen individuals lacking any evidence of orange on the initial abdominal segments.

Distribution: Texas; south through Mexico to Panama

Source: Abbott, J.C. 2006-2010. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at OdonataCentral.

Edited by Drew Weber (9/24/2015).