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Rambur's forktail
Rambur's forktail (Ischnura ramburii) [female]
Photo © Mary Kay Rubey
Rambur's forktail (Ischnura ramburii) [male]
Photo © Mary Kay Rubey
Features and Behaviors
FEATURES
This small (one to one-and-one half inches) damselfly is tricky to identify, appearing differently between the sexes and with age. Males have green eyes with black caps, and tiny blue spots behind their eyes of the top of their head. Their thorax is bright green below and dark metallic green top. Females have three different appearances: an immature form, a mature form, and andromorph (male look-alike). Female andromorphs look much like the males, but the underside of their thorax is blue, not green. Immature females have orange-brown eyes that become lighter towards the bottom. Their thorax is mostly orange with metallic dark green on the top, and they have orange legs. Their abdomen is dark metallic green on top and bright green below, with orange color at each end. The mature females are similar to the immature, but the legs are brown, and the eyes, post-ocular spots, thorax, and base of the abdomen are dull, tan-green.
BEHAVIORS
Despite their small size this damselfly is a voracious predator, often taking on prey as large as themselves. Females especially are known to predate on other damselflies equal their size. They inhabit emergent vegetation on the margins of lakes, ponds, and marshes and are most active in the afternoon. They mate on the ground, on grasses, and the stems of plants. The male grabs the female by the back of the head with the end of their abdomen and the female curls her abdomen forward to form a heart-like shape. They mate from two to seven hours. Eggs are deposited in the late afternoon on floating leaves and stems. We are on the very northern range of the Rambur’s forktails range; it only occurs in the very southern part of Illinois and they can be seen in flight from June to July.
Illinois Range
Taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Odonata
Family: Coenagrionidae
Illinois Status: common, native
