With its colorful wings and bouncing, fluttering flight, it’s sometimes mistaken for a butterfly.
But the Halloween Pennant (Celithemis eponina) is actually a dragonfly, in the insect group Odonata, which also includes slimmer relatives of dragonflies called damselflies.
Its common name is appropriate, as all four wings display Halloween colors — brown or blackish bands on an orange-yellow background. Adults tend to perch at the very tips of grasses and other plants, swaying like flags (pennants) in the breeze.
The species is distributed throughout much of the eastern United States near lagoons, ponds, lakes, and marshes.
Like other dragonflies, Halloween Pennants spend the immature part of their life cycle as wingless larvae, hatching from eggs laid in the water and inhabiting bottom mud and sediments. They breathe via gills and prey on tiny invertebrates, even fish fry, shedding their outer “skins” several times to accommodate growth.
Once fully developed, the larvae crawl onto the shore, molt one last time, and emerge as winged adults.
Then they spend the next week or two away from the water, foraging for mosquitoes, midges, and other aerial prey.
The life cycle is completed once males and females attain sexual maturity and return to ponds and lakes to reproduce.
Dragonflies have unique mating behavior — and the Halloween Pennant is no exception. Using specialized claspers at the end of his abdomen (last body segment), the male grasps the female’s head while the two are in mid-air. If receptive, she curls her own abdomen forward to pick up sperm that he’s stashed in an internal receptacle towards the front of his body. She stores these sperm in her own internal storage organ, and they’ll fertilize the eggs just before they’re laid in the water.
In some dragonflies, members of a pair separate after sperm transfer, and the male hovers near the female, guarding her from other males during egg-laying.
In other species, including the Halloween Pennant, the male stays attached to the female – a more secure form of protection — and the pair flies about in tandem as the female releases eggs into the water.
In either case, these forms of mate-guarding protect the male’s “sperm investment” in the female. If she were to mate again with a rival, the first male’s sperm would be displaced towards the rear of the female’s storage sac. Then the second male would end up fertilizing most of the eggs.
Halloween Pennants are found in the Lowcountry from spring to early fall, though they can be locally abundant — common in some areas, absent from others.
They’re one of over 150 kinds of dragonflies and damselflies found in South Carolina.