Description:
Males: Eyes mostly blue, with small black cap. Postocular spots elongated joints. Typicaly bluet thoracic stripes, but median stripe prominently divided. Abdomen blue with black markings. Superior appendages with inferior arm appearing as a broad triangular process, the apex directed ventrally. S2 with the black of the dorsum usually extending from base to apex, black apical rings and rearward-pointing on S3-6, S7 with black dorsum almost entirely, S10 blue with a narrow median stripe of black
Females: Polimorphic, either brown or blue on thorax and abdomen; Abdomen tipical bluet black above, apical ring on S3- S8 mostly pale except median dorsal line, S9 mostly black but pale apical lateral spots (Paulson, 2009).
Size: Total length: 27-34 mm; hindwing: 13-19mm.
Similar Species: Males are different from other species by the large black basal marks in the middle abdominal segments. Due to the amount of black in the abdomen, it may be similar to Arroyo bluet at first sight. It can be confused for mostly blue Dancer, also because S10 with so much blue, but the black back marks are different from the black side marks of the dancers. Females distinguished from all co-occurring bluets by mostly pale S8 with dark median line. Most similar to femal Claw-tipped Bluet, but that speces has S8 blue above and black below.
Habitat: Shallow rocky and sandy streams in arid country, mostly on pools.
Natural History: It is possible to observe the males in the emergent vegetation, although they are also observed very far from the water, in the desert scrub. No reproductive behavior has been reported.
Distribution: This species was considered endemic of Baja California, nevertheless it was located in two localities one in Arizona and another in California.
Source:
Byers, C. F. 1927. Key to the North American Species of Enallagma, with a Description of a New Species(Odonata: Zygoptera). Transactions of the American Entomological Society 53(3): 249-260
Paulson, D. 2009. Dragonflies and Damselflies of the West. Princeton University Press. 536 pp.
Edited by Juan Cruzado (02/05/2017)
