pronghorn clubtail

(Phanogomphus graslinellus)

Conservation Status
pronghorn clubtail
  IUCN Red List

LC - Least Concern


N5 - Secure

SNR - Unranked


not listed


Pronghorn clubtail is a relatively robust, medium-sized dragonfly. It occurs mostly in central United States and southern Canada. In Minnesota it is most common in the central and north-central regions, less common in the metro and southeast regions, rare in the Arrowhead, and absent from the southwest.

Adults are 1¾ to 2316 (44 to 55 mm) long. The body is black with extensive yellow markings.

The head is small. The face is greenish-yellow. The large compound eyes are blue or gray and do not meet at the top of the head. The area behind the compound eyes at the top of the head (occiput) on both sexes is yellow.

The thorax is yellowish-green or greenish-yellow with several black stripes. The middle stripe on the upper side (middorsal stripe) is broad and has parallel sides. On each side there are two upper stripes (humeral and antehumeral stripes) that are partly fused together but separated in the middle by a thin pale stripe.

The abdomen is slender and black with yellow markings. The upper (dorsal) surface or abdominal segments 1 through 7 have yellow, elongated, triangular spots. Segment 8 has a triangular spot at the base and sometimes a thin line extending from the triangle to the rear margin of the segment. Segment 9 has a broad stripe from the base top the rear margin. Segment 10 has a narrower stripe. Segments 8, 9, and 10 are expanded into a noticeable “club”. The sides of segments 8 and 9 have bright yellow along the entire margin. At the tip of segment 10 the male has a pair of distinctive, widely forked claspers (cerci). Each cercus has an outward-pointing “horn”, like a pronghorn antelope, for which this dragonfly gets its common name.

The legs are dark brown to black. The third leg segment (femur) on the female is streaked with green, on the male black it is entirely black. The upper (dorsal) surface of the fourth leg segment (tibia) on both sexes is yellow.

The wings are clear except for a dark cell (stigma) on the leading edge near the tip. The leading edge of the vein on the front margin (costa) of each wing is bright yellow.




Total Length: 1¾ to 2316 (44 to 55 mm)


Similar Species


Ponds, lakes, and slow streams.




Mid-May to mid-August






Life Cycle




Nymph Food




Adult Food




Distribution Map



7, 17, 27, 29, 30

IUCN Red List







Odonata (dragonflies and damselflies)  


  Infraorder Anisoptera (dragonflies)  




Gomphidae (clubtails)  



Until recently, this dragonfly was classified as Gomphus graslinellus. In 2007, the four subgenera were raised to genus rank. The genus Gomphus now contains only European species.




Gomphus graslinellus


Common Names


pronghorn clubtail









One of a pair of small sensory appendages at the end of the abdomen of many insects and other arthropods. In Odonata, one of the upper pair of claspers. Plural: cerci.



On ferns: The central axis of a pinna, to which pinnules are attached. On mosses: the central axis (midvein) of a leaf. On insects: The vein on the leading edge of the forewing.



On insects and arachnids, the third, largest, most robust segment of the leg, coming immediately before the tibia. On humans, the thigh bone



The back of the head. In Odonata, Megaloptera, and Neuroptera, the upper part of the head behind the eyes.



In plants, the portion of the female part of the flower that is receptive to pollen. In Lepidoptera, an area of specialized scent scales on the forewing of some skippers, hairstreaks, and moths. In other insects, a thickened, dark, or opaque cell on the leading edge of the wing.



The fourth segment of an insect leg, after the femur and before the tarsus (foot). The fifth segment of a spider leg or palp.






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    pronghorn clubtail   pronghorn clubtail  






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Other Videos
  Clubtail Dragonfly (Gomphidae: Gomphus) Waiting for Prey
Carl Barrentine

Jun 13, 2012

Photographed at the Turtle River State Park, North Dakota (12 June 2012). Either a female Gomphus graslinellus or a Gomphus exilis, I think.

  Pronghorn Clubtail
Bob Rubey

Jun 20, 2015

Silver Springs SP, Yorkville, IL
June 19, 2015




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Created: 7/17/2020

Last Updated:

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