About Onychogomphus uncatus (Charpentier, 1840)
Onychogomphus uncatus is a species of dragonfly first described by Charpentier in 1840. Adult individuals of this species reach a maximum length of 65 millimeters, or 2.6 inches. Their eyes are widely separated, and colored bright blue or gray-blue, never green. The front black line on the side of the thorax does not reach the midline of the body. The yellow collar at the front of the thorax is interrupted by a black bar. This species has four cells in the anal triangle of the hind wing, and lacks a yellow line on the vertex. Its cercoids are always yellow. Onychogomphus uncatus is larger and rarer than the closely related small pincertail, Onychogomphus forcipatus, and the two species are quite similar in appearance. They can be told apart by the shape and extent of their black markings, especially the markings on the thorax and the last abdominal segments. This dragonfly species is found in Belgium, France, Germany, Italy, Spain, Portugal, and Switzerland. It typically occurs near running water and lakes.
