green-faced clubtail

not listed

N3 - Vulnerable

SNR - Unranked

not listed

Green-faced clubtail is an early season, medium-sized clubtail. While it is more common in the northeast than in Minnesota, it is uncommon and considered rare over most of its range.

The upper (dorsal) side of the thorax is pale grayish-green on top with black markings including a broad central (middorsal) stripe, two lateral stripes, and a shoulder stripe. The side of the thorax is grayish-green with an incomplete first (anterior) stripe that arches around to join the shoulder stripe. There is no middle stripe found on most other clubtails.

The abdomen is slender and black with yellow markings. Abdominal segments 1 through 7 have small yellow dorsal spots and larger yellow lateral spots. On the male the dorsal spots are tiny. On the female they are larger but still small. Segments 8 through 10 are unmarked on top. Segment 9 is shorter than segment 8. Segments 8, 9, and 10 are expanded into a noticeable “club”.

The head is small. The large compound eyes are green. They do not meet at the top of the head. The area behind the compound eyes at the top of the head (occiput) is slightly convex. The face is grayish-green with a single horizontal stripe on the lower part of the face above the upper lip (labrum) that is divided in the middle horizontally.

The legs are black.

The wings are clear except for dark stigmas. The wing triangle, a section of intersecting veins about 20% of the way from the base to the wingtip, is about the same size in the forewing and the hindwing.

The female is similar but may have yellowish markings, especially on the face.

Total length: 1¾″

Rapid medium streams and rivers with gravel, silt, sand, and rocks

Mid-may to mid-July

Males are most active in late afternoon, especially under cloud cover.

The female does not have an ovipositor. She lays her eggs by washing them off in fast-flowing water. The eggs flow into slow water where the young (naiads) develop.

Sources

7, 17, 18, 29, 72.

Uncommon