New York Natural Heritage Program
Rambur's Forktail
Ischnura ramburii (Selys, 1850)
Insects

Identifying Characteristics [-]
Ischnura ramburii males have green shoulder stripes on the tops of the thorax and pale green sides. The abdomen is black with pale rings. Abdominal segment 8 is usually all blue and blue is present on the sides of segments 9-10. Postocular spots are small, round, and blue. Females have three color forms: male-like, orange, and mature olive. The male-like form has more bluish tinting to pale areas than males, but is otherwise similarly patterned. The orange form has an orange thorax, no shoulder stripes, and a broad, black mid-dorsal (top) stripe. The base of the abdomen is orange in this form and the rest of the abdomen is black (Nikula et al. 2003). The mature olive form has an olive-sided thorax and abdominal segments 1 and 2 are mostly pale, with the rest of the segments black on top (Lam 2004).
The Best Time to See
New York records from the 1990s to present indicate a flight season from June 14 to September 2 (New York Natural Heritage Program 2010). An unvouchered observation was made on 9/14/2009 and older records indicate the species can be observed into October (Donnelly 1999). The species flies from June 8 through November 1 in New Jersey (Bangma & Barlow 2010).
J F M A M J J A S O N D
Present Reproducing
The time of year you would expect to find Rambur's Forktail present (blue shading) and reproducing (orange shading) in New York.
Similar Species
  • Eastern Forktail (Ischnura verticalis)
    The Eastern Forktail is smaller than Rambur's, and the male is blue on the top of abdominal segments 8-9, with green postocular spots. The orange female of I. verticalis has dark shoulder stripes, while I. ramburii lacks these (Nikula et al. 2003).
  • Furtive Forktail (Ischnura prognata)
    Segment 9 of the male Furtive Forktail is all blue, while only segment 8 is blue in the male Rambur's Forktail.