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cobra clubtail
cobra clubtail (Gomphurus vastus) [female] [male]
Photos © Mary Kay Rubey
Features and Behaviors
FEATURES
Cobra clubtails are dark dragonflies with a wide club at the end of their tail, shaped almost like the hood of a cobra, hence the common name. The size is much larger in southern regions. Males have green eyes and a yellow face with horizontal black stripes. The thorax is diagonally striped black and light green. The middle top of the thorax is mostly black with thin yellow pointed dashes continuing down the length of the abdomen and stopping just before the club tail. Legs and abdomen are black, excluding yellow dashes on the top and yellow spots on the eighth and ninth sections of the club tail. The female is colored similarly to males, but with more yellow on the sides of the abdomen, and dashes on the top of the abdomen are longer, and closer together.
BEHAVIOR
Males can be found perching with an elevated abdomen on the shore and on rocks in rocky rivers, then suddenly fly up and down. Typically, they hover facing the wind or flying two to three feet above the water’s surface. At one river, males were observed to be actively flying until dark. Males and females perch on leaves with downward inclined abdomens. Mating pairs perch on trees, shrubs, and tall weeds at or above head height. Females lay eggs rapidly flying and tapping the water at intervals, far from shore. They like sandy/silty bottom streams and rivers with slow currents, with or without rocks. They also like large lakes with rocky borders in the north. Found throughout Illinois. Their range is as far north as southern Canada and as far south as the panhandle of Florida.
Illinois Range
Taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Odonata
Family: Gomphidae
Illinois Status: common, native
