The Rambur’s Forktail Damselfly

WHAT WETLANDS PARK DAMSELFLY CAN BE “DISTRESSING” TO OTHER DRAGONFLIES?

Ponds and stream edges at Clark County Wetlands Park are alive with jeweled flyers in spring, summer, and fall.  Dragonflies and damselflies wheel in the air, perch in vegetation and on rocks and fence railings, and lay their eggs to ensure a new generation. These colorful insects are not looking for flower nectar or pollen – all dragonflies and damselflies are predators, dining on other small creatures.  Ramber’s Forktail damselflies, particularly the females, just happen to vary the more usual damselfly diet of flies, mosquitoes, and other small insects with other damselflies!

Damselflies and Dragonflies together make up a very ancient order of insects – the Odonata. They first appear in the fossil record with the dinosaurs, about 250 million years ago. Over 6,000 odonates now flash through the air over every continent except Antarctica, and over all islands large enough to have sources of fresh water.

Damselflies are generally smaller and slenderer than the more robust-looking dragonflies, and their flight appears slower and more “fluttery,” an adaptation to hunting among the leaves and stems of plants.  Their long, slender abdomens have ten segments, numbered from front to back.  Their large eyes, unlike the eyes of dragonflies, do not overlap.  The forewings and rear wings of damselflies,  unlike those of dragonflies, are relatively narrow and about the same shape.  When a damselfly is resting, its wings (except in “spreadwing” damsels), are held together above its body rather than spread to the sides like a perched dragonfly’s.  This gives the damselfly suborder its name:  Anisoptera, which means “yoked wings,” since the wings appear to be connected to each other above the damsel’s back.

Rambur’s Forktail damselflies (Ischnura ramburii) are found across much of the United States and south through Mexico.  They favor habitats along ponds, lakes, slow streams and marshes with lots of vegetation for cover, and available areas of sunlight, so Clark County Wetlands Park is perfect habitat for them.  These damselflies can breed in brackish water and are often seen near the ocean shore in marshes and estuaries, as well as freshwater marshes, ponds, and streams.

Adults usually do not wander far from the water’s edge, and both sexes are found at or near the water most of the time. They fly along open stretches of shoreline and will often perch on bare ground or in plain view (like our photo model). This is unusual for most forktails, which prefer to shelter in low, dense, vegetation where they are difficult to see.  At night, the Rambur’s Forktails rest in dense patches of vegetation, perching with their abdomens parallel to stems.  Interestingly, if they are disturbed while resting at night, they will move to the opposite side of the perch stem, but prefer not to fly off.

Identifying damselflies takes a bit of practice and persistence.  Forktail damselflies are named for a forked projection found in most males at the end of abdominal segment ten.  Males have green eyes with black caps and tiny blue spots behind each eye.  The thorax is green with two yellowish-green shoulder stripes. The abdomen is shiny black above, and golden on the sides.  Segment eight is solid blue, and segments nine and ten are black above and blue on the sides.  Segment nine is also solid blue in males from the western United States.

Females are even trickier to identify!  Some, called andromorphs, are identical to males in appearance – easy!  The majority look quite different.  They are called heteromorphs, and the spots behind their eyes, thoraxes, and segments one and two of their abdomens are bright orange with a black midline.   Segments three to ten of their abdomens are black above, pale greenish on the sides of segment three to seven, and orange on the sides of segments eight to ten. For excellent photos to help with identification, try a visit www.arizonadragonflies.com. Pierre Deviche’s photos are amazing!

Sneak closer for a good look if you spot a good-sized blue, green, and black damselfly whirring through the air along a pond margin, and especially if you find a “damsel” perched on a flat surface in the open or on an exposed stalk of vegetation at the Park.  It might be a Rambur’s!  If you watch for a bit, you may see it dart from its perch to capture a meal in flight.  Often, the damselfly will return to its perch after a hunting sally (sometimes flying backwards), giving you another chance to see it.  Close-focus binoculars are a wonderful investment for nature watchers. They bring all kinds of small wildlife into sharp focus without frightening them away!                                                                                         

– By Chris Leavitt, President; photo Phil Martini

Please enjoy these YouTube videos!

Rambur’s forktail Damselfly HD RJ Wiley        2:03

Rambur’s forktail-Ischnura ramburii-damselflies mating, Wakodochee Wetlands

Rambur’s forktail eating a bluet Joe MDO