Species umbrosa Walker, 1908 [Aeshna]
Syn Aeschna occidentalis Walker, 1908
This is a rather common widespread midsummer species found in the northern parts of the region. It has a greenish-brown face and the black "T" on top of the frons is constricted slightly in the middle. The pterothorax is brown with yellow-green parallel thoracic stripes both dorsally and laterally. The abdomen is strongly constricted beyond the proximal segments. The pale areas are blue (western fo rm ) or green (eastern form ) and generally there are pale blue spots visible ventrally on segments 4-6 and sometimes 7. This pattern is distinctive of this species. Females are generally green, but some individuals are blue.
Total length: 68-76 mm; abdomen: 49-59 mm; hindwing: 42-48 mm.
Within the eastern part of its range, Shadow Darners are the most similar to Lance-tipped Darners (A. constricta), but the back of the head is black, not pale and Lance-tipped Darner has the usual pale blue abdominal spots. In the west Paddle-tailed Darner (A. palmata ) is similar, but it has a distinctive black stripe across the front of the face and the lateral thoracic stripes are generally wider. Females Blue-eyed Darners (A. multicolor ) have a ventral tubercle on abdominal segment 1. Lance-tipped females have blue spots on segment 10.
Partly shaded, slow-flowing forest streams and ditches.
Two forms of this species have been recognized, the typical "umbrosa," found in our region and throughout the eastern United States, and a Pacific-Northwestern form, "occidentalis." This species is unique in the group, tending to prefer shaded habitats. Females lay eggs in wet decaying wood and aquatic plants. One study found prey consisted of mainly small flies.
Found throughout much of North America and Canada extending southward to Georgia westward through Oklahoma, Texas, New Mexico and California.