shadow darner

LC - Least Concern

N5 - Secure

SNR - Unranked

not listed

Shadow darner is a common and widespread, 2¾″ to 3″ long, mosaic darner (genus Aeshna). It is found throughout North America except in the arid southwest and, for some reason, Newfoundland. It is a late-season dragonfly. Only the autumn meadowhawk (Sympetrum vicinum) flies later in the year.

The face is pale grayish-green and lacks the black horizontal stripe found on many other species of dragonflies. There is a black T-shaped spot on the upper part of the face (frons) below where the eyes meet. The lower leg of the T spot is slightly constricted in the middle. The compound eyes meet along a long margin at the top of the head. The lower back of the head is brown.

The thorax is brown with two shoulder (dorsal) stripes and a pair of side stripes on each side. The shoulder stripes are blue. The side stripes are parallel and greenish-yellow for most of their length, fading to bluish-green at the top. The front (anterior) stripe is straight and complete, not bent, notched, or interrupted. The bottom widens slightly and there is a small rearward extension at the top.

The abdomen is brownish-black and slender. Abdominal segment 3 is elongated and noticeably constricted when viewed from above. Abdominal segments 1 through 9 have a pair of pale blue spots on the upper (dorsal) surface that get darker in cool weather. Abdominal segment 10 on the male is unmarked. These spots are narrower than those on other blue darners. The pale areas on the underside on the abdomen are large, bright, and green on the eastern subspecies, blue on the western subspecies. Females are usually colored similar to males but there is a rare green form female with green dorsal spots on the abdomen.

On the male the pair of appendages at the end of the abdomen (cerci) are expanded at the tip and twisted downward. They appear wedge-shaped when viewed from the side.

The wingspan is about 3⅜″ to 4″. The wings are clear. The forewings are slightly narrower than the hindwings.

2¾″ to 3″

Shaded areas alongside slow streams, ponds, and swamps; ditches.

Late June to late October

Adults hunt mostly in the shade and mostly at dusk.

The female deposits eggs either in wet rotting wood of a floating or submerged log or inside the stem of emergent vegetation. The eggs hatch about a week later or, in harsher climates, enter a period of decreased metabolic activity (diapause) that lasts up to 7 months. The hatched larva (naiad) grows to be 1½″ to 1¾″ long. In Minnesota it usually takes a year for a naiad to mature and emerge as an adult. In warmer climates the naiad matures in about 2 months. In colder climates it may take several years. Most adults live for about 2 weeks, though those who endure a harsh winter as a naiad may live 2 months or more.

Mostly aquatic insect larvae, but also freshwater shrimp, tadpoles and small fish.

Mosquitoes, midges, other dragonflies, moths, grasshoppers, beetles, and any other insects smaller than themselves.

Sources

7, 17, 18, 27, 29.

Common and widespread in Minnesota