eastern forktail

Eastern forktail is a small, narrow-winged damselfly. It occurs east of the Rocky Mountains from Quebec and Georgia in the east to Manitoba and New Mexico in the west. It is very common in the northeast and Midwest, present but uncommon in the southern tier of states. It is abundant in Minnesota, where it has been reported in 81 of the state’s 87 counties.

Adults are ⅞″ to 1 3 ⁄16″ (22 to 30 mm) long.

On the male, the face is green. The top of the head is black. The compound eyes are mostly green, black just on the top. There is a small, bright green, circular spot (postocular spot) behind each eye. The spots are not connected by a bar.

The thorax is black with narrow green shoulder stripes and pale green sides. The stripe is often narrowest at ⅔ its length. On rare individuals, the stripe is broken, as it is on the closely related fragile forktail.

The abdomen is very slender and mostly black, with a pale, very narrow ring at the tip of each segment. Abdominal segments 8 and 9 are bright blue above and below, but on the sides they are black on the leading half and bright blue on the apical half. There is a forked projection on the upper side of segment 10 that gives this genus the common name forktails. The projection is blunt and is forked for half of its length. It points more upward than rearward, and does not extend beyond the tip of segment 10. The projection is too small to be used as a field mark, but may be discernible in photos.

The wings are clear and are distinctly narrowed (stalked) at the base. There are only two cross veins between the base of the wing and the wing notch (nodus). The median vein intersection, where the M₃ vein rises to meet the M₁ vein, occurs after the nodus, closer to the nodus than the basal cross vein (arculus).

The legs are short and armed with spines. They are black above and on the sides, pale blue below.

Immature females are black with orange markings. Abdominal segment 2 and the basal half of segment 3 are orange. Segments 4 through 10 are black. The back of the head, the postocular spots, and the legs are orange.

Mature females are entirely covered with a pale blue powdery bloom (pruinose), obscuring any black or blue markings that may or may not be there. The postocular spots are pale blue and are larger.

Total length: ⅞″ to 1 3 ⁄16″ (22 to 30 mm)

Ponds, marshes, slow streams, and other wetlands

Late May to early October

Eastern forktail is a weak flier and is usually found low in vegetation. The wings are held together above the body when at rest.

Flying insects

Sources

7, 18, 24, 27, 29, 30, 82, 83.

Widespread and very common. Abundant in Minnesota.

Adult Male

Immature Female

Adult Female

Adult Female

Ischnura verticalis eastern forktail

Ischnura verticalis eastern forktail, on goldenrod leaf, near the pond at Barnes Prairie, Racine Co., WI. Photo taken on August 6, 2022.

An eastern forktail in The Big Stone National Wildlife Refuge with the morning dew on the grass.

Eastern Forktail (Ischnura verticalis)
Andree Reno Sanborn

Eastern Forktail (Coenagrionidae: Ischnura verticalis) Male Resting
Carl Barrentine

Eastern Forktail (Coenagrionidae: Ischnura verticalis) Male Tail-flipping Behavior
Carl Barrentine

Ischnura verticalis
DocBebitte

Eastern Forktail Damselflies (Coenagrionidae: Ischnura verticalis) on Twig
Carl Barrentine

Location: Albany, NY

Location: Albany, NY

Alfredo Colon
7/7/2024

Location: Albany, NY

Location: Barnes Prairie, Racine Co., WI

Ischnura verticalis eastern forktail, on goldenrod leaf, near the pond at Barnes Prairie, Racine Co., WI. Photo taken on August 6, 2022.

Location: Reno Quarry Trail, Reno North Recreational Area

Location: Woodbury, Minnesota

Location: Big Stone National Wildlife Refuge

An eastern forktail in The Big Stone National Wildlife Refuge with the morning dew on the grass.

Location: Woodbury, Minnesota