Dragonflies and Damselflies

 

Halloween Pennant (Celithemis eponina), a large, brightly 
colored dragonfly resting on a plant stem.
Palm Beach County, Florida. 

There are many kinds of flies in the insect world; house, horse, deer, fruit, May, black and others.  But none fire the imagination like dragonflies.  Their very name invokes fairy tales and fantasy.  The dragonfly’s close relatives, the damselflies, feed into these same tales with images of ladies in distress.  But these insects are interesting in their own right.  They are highly diverse, they are fierce predators and they have a fascinating life history.   

True flies, in the Order Diptera, have two wings but dragonflies and damselflies are not really flies.  They are classified in the Order Odonata and have four wings.  Giant ancestors of these insects from the age of dinosaurs had a wingspan of over two feet. Both dragonflies and damselflies have large compound eyes, a long abdomen and of course, six legs.   A key difference between damselflies and dragonflies is how they position their wings.  Dragonflies usually hold their wings straight out when perched while damselflies fold their wings over their back. Dragonflies and damselflies lay their eggs in fresh water and the larval state, called a nymph, develops in ponds and slow-moving streams.  Both dragonflies and damselflies are carnivores, eating invertebrate animals at each stage of their life cycle.    

Dragonfly nymph in the Family Libelluidae.  This family
includes several of the dragonflies in this blog.
Rowan County, North Carolina. 

North America hosts more than three hundred species of dragonflies.  Dragonflies are strong flyers, with some species reaching 30 miles per hour.  In North America, several species of dragonflies undertake long, multigenerational migrations from Canada to the Neotropics and back. The adults are aerial predators that catch other insects like flies and mosquitos on the wing.  Dragonflies have giant eyes that take up most of their heads and give them 360-degree vision.  They are highly efficient hunters an( capture 95% of the prey they chase.  Dragonfly legs have long bristles that act as a cage to capture insects in flight.  

A male Eastern Pondhawk.
Rowan County, North Carolina.

The Eastern Pondhawk (Erythemis simplicollis) is common dragonfly in Eastern North America, the West Indies and Central America. Eastern Pondhawks are aggressive predators. They fly from a perch, catch their insect victims on the wing then return to the perch to eat. Female Eastern Pondhawks are bright green and males change from green to blue as they mature.

A bright green female Eastern Pondhawk. 
Clay County Florida. 

The Blue Dasher (Pachydiplax longipennis) is a large, active dragonfly that also hunts from a perch.  When a Blue Dasher sees a prey insect, it dashes from its perch to catch its meal.  Blue Dashers have large green eyes, a yellow striped thorax and in the males, a bright blue abdomen.  Climate change has allowed this species to extend their range into Canada.  

A Blue Dasher (Pachydiplax longipennis) on a hunting perch.
Palm Beach County, Florida.

Halloween Pennants (Celithemis eponina) have a striking orange and black Halloween pattern on their wings.  When perched, Halloween Pennants often hold their wings up rather than out to the side so they look like they are flying pennants.  In most of their range, Halloween Pennants are not flying on Halloween, but in Florida they can be seen on their eponymous holiday. 

 

Halloween Pennant with its wings raised.
Palm Beach County, Florida.

Halloween Pennant with its wings in the normal position. 
Palm Beach County, Florida.

The Common Whitetail (Plathemis lydia) is another abundant dragonfly throughout North America.  Male Common Whitetails have a wide, white abdomen and clear wings with a wide dark band at mid-wing and a small dark mark near the body.  Females of the species have a brown abdomen with transparent wings decorated with three dark bands.   

Male Common Whitetail (Plathemis lydia).
Rowan County, North Carolina.

Female Common Whitetail.
Rowan County, North Carolina. 

A striking dragonfly found in Florida is the Scarlet Skimmer (Crocothemis servilia).  This native of Asia has been introduced to Florida, Hawaii and Jamaica where it lives in swamps, marshes and near canals.  

Scarlet Skimmer (Crocothemis servilia).
Palm Beach County, Florida. 

Damselflies are smaller and more lightly built than dragonflies.  Damselfly flight is slow and fluttery compared to the fast and direct movement of dragonflies. The eyes of damselflies are smaller than those of dragonflies but bulge out from the head.  In other words, they are bug-eyed.     

Blue-tipped Dancer (Agria tibialis).  Like all damselflies
Blue-tipped Dancers fold their wings over their backs.
Rowan County, North Carolina. 

The Blue-tipped Dancer (Agria tibialis) is a delicate little damselfly with clear wings, dark body and in the male, a bright blue tip to the abdomen.  Blue-tipped Dancers are found near streams and ponds throughout Eastern North America.

Male Ebony Jewelwing (Calopteryx maculata) with all black wings.
Rowan County, North Carolina. 

 

Female Ebony Jewelwing with white spots at the ends of her forewings.  
Weymouth Woods Sandhills Nature Preserve, North Carolina. 

Ebony Jewelwings (Calopteryx maculata) are the most dramatic damselflies in our area.  With black wings and iridescent blue-black bodies, these large damselflies are often seen flying in the forest understory.  Male Ebony Jewelwings have all black wings while females have white spots near the tip of their forewings.  

Dragonflies and damselflies play important roles in the environment.  They consume vast numbers of insects including mosquitos that may carry disease causing microbes.  Dragonflies and damselflies are predators, but are also prey to many species.  The nymph stage is eaten by other insects, frogs and fish.  Adults are caught on the wing by bats and acrobatic birds including swallows and kites.  We have watched dozens of Mississippi Kites (Ictinia mississippiensis) flying over farm fields catching dragonflies and eating them on the wing.  Their association with water at all stages of the lifecycle makes them sensitive to pollution so they are indicators of environmental quality.  Large numbers of dragonflies or damselflies is a sign of a healthy ecosystem. 

Halloween Pennant.
Palm Beach County, Florida.

As we walk the fields and stream-sides this summer we will be watching these fast flying, keen eyed predators whose very names come to us from fantasy.

Ferns and Fiddleheads

 

A Christmas Fern (Polystichum acrostichoides) in spring. The 
fronds of this fern sprout from the underground rhizome.
Rowan County, North Carolina.  

Ferns are members of an ancient and distinguished lineage. Even today ferns remain significant members of the world’s flora.  Ancient, fern-like plants appeared in the fossil record over 300 million years ago during the Devonian Period. This was when the first land animals and plants emerged, including the ancestors of today’s ferns.  Ferns saw the rise and fall of the dinosaurs and the ascendance of mammals including humans. There are over 10,000 ferns species alive today, most of them living in the tropics.  North America is home to about 380 fern species. 

Most ferns have compound leaves, called fronds.  Compound leaves resemble bird feathers (pinnae) and are thus said to be pinnately compound.  The central vein of the leaf, the rachis, supports the many leaflets.  Ferns reproduce by making spores and certain fronds bear sporangia, the spore producing structures.  The stems of many ferns grow below ground and are called rhizomes.  Rhizomes make the fronds that erupt from the soil.  New fern leaves are tightly coiled when they emerge.  This coiling protects the frond’s delicate, developing leaflets.  As the coil unrolls the leaflets at the base of the frond emerge first and the tip of the leaf unrolls last. These young coiled fern leaves are called fiddleheads because they resemble the scrollwork at the end of a violin’s neck. 

Leaflets of Christmas Fern. The base of each
leaflet has a "thumb" that makes it resemble a Christmas stocking.
Rowan County, North Carolina.

A fiddlehead of Christmas Fern.
Rowan County, North Carolina.

Perhaps the most common fern in our area is Christmas Fern (Polystichum acrostichoides).  Christmas Ferns are found throughout eastern North America and grow in the forest understory.  Their name refers to the fact that the fronds are still green at Christmastime.  Christmas Ferns have pinnately compound leaves that can be over a foot long and may have 20-30 leaflets.  The base of each leaflet has a triangular lobe that is said to resemble a Christmas stocking, further reinforcing the name.  In early spring fiddleheads emerge from the underground stems.  Some fronds have leaflets with brown sporangia on their lower surface.  These spore-bearing leaves are called fertile fronds.  Spores are released into the air and float away, hopefully to establish new Christmas Ferns.  

A fertile frond of Christmas Fern. The dark brown
underside of the terminal leaflets are producing spores.
Rowan County, North Carolina. 

Another common fern of Piedmont North Carolina is Rattlesnake Fern (Botrychium viginianum). This fern has compound leaves and a fertile frond of compact leaflets bearing sporangia.  The common name for this plant comes from the resemblance of its fertile fronds to the rattles on their namesake pit viper.  The genus of Rattlesnake Fern, Botrychium, also includes Grape Ferns. These ferns get their name because the fertile fronds look like little bunches of grapes.  

Rattlesnake Fern (Botrychium virginianum) with a spore bearing 
fertile frond. Rowan County, North Carolina.

Ophioglossum pyncnostichum goes by the common name of Southern Adder’s Tongue.   This small fern is in the same family as Rattlesnake Fern but has a single, simple leaf rather than compound leaves.  The Southern Adder’s Tongue leaf has an upright segment that bears the spores.  The people who named this fern thought this spore making structure looked like the tongue of a snake.  

Southern Adder's Tongue (Ophioglossum pyncnostichum) with its simple 
leaf that is just starting to produce the spore bearing segment.
Rowan County, North Carolina. 

Southern Adder's Tongue with a mature fertile spike.
Rowan County, North Carolina.

Detail of Southern Adder's Tongue spore producing structure.
Rowan County, North Carolina. 

A delicate fern with a delicate name is Northern Maidenhair Fern (Adiantum pedatum).  Its fronds extend in a horizontal, circular arrangement.  Northern Maidenhair Fern grows in the rich woods of the mountains and Piedmont.

Northern Maidenhair Fern (Adiantum pedatum) fronds.  
Davidson County, North Carolina.

Southern Lady Fern (Athyrium asplenioides) and Netted Chain Fern (Woodwardia areolata) both make fairly large fronds and are common in moist woods in the Southeast.  Southern Lady Fern has twice-pinnately compound fronds, that is each leaf has leaflets each of which in turn also bears leaflets.  Netted Chain Fern has compound leaves with leaflets whose blades run along the rachis.

 

Southern Lady Fern (Athyrium asplenioides) fronds.
Rowan County, North Carolina. 

Netted Chain Fern (Woodwardia areolata) frond.
The blades of the leaflets extend onto the rachis in this fern.
Rowan County, North Carolina. 

A very odd fern, Shoestring Fern (Vittaria lineata), is found in south Florida, on Caribbean Islands and in Central and South America. The fronds of Shoestring Fern are simple rather than compound and look like green shoestrings.  Shoestring fern grows as an epiphyte, usually on Cabbage Palm (Sabal palmetto) trunks. 

Shoestring Fern (Vittaria lineata) growing on the 
trunk of Cabbage Palm (Sabal palmetto).
Palm Beach County, Florida.

Another unusual South Florida fern is Acrostichum danaeifolium, the Giant Leather Fern.  It is indeed a giant with fronds reaching over six feet in length.  This fern grows in swamps and marshes throughout southern Florida and into the American tropics.  Fertile fronds bear leaflets with brown sporangia on the underside.  Giant Leather Fern cannot tolerate frost and its northern distribution is limited by freezing weather. 

Giant Leather Fern (Acrostichum danaeifolium) growing in a marsh.
Palm Beach County, Florida.

Giant Leather Fern with sporangia.
Palm Beach County, Florida. 

Hawaii hosts several giant ferns, one of which is the Hawaiian Tree Fern, Cibotium menziessi.  These ferns are truly trees and can reach over thirty feet in height.  They grow on the rainy, windward side of the Hawaiian Islands and are a major trees of the rainforests there.  Hawaiian Tree Ferns have a starchy pith and are eaten by invasive feral pigs and are also threatened by over-harvesting. 

Hawaiian Tree Fern (Cibotium menziessi).
This fern can reach 30 feet in height. 
Hawaii Volcanoes National Park, Hawaii.

Fiddle head of Hawaiian Tree Fern.
Hawaii Volcanoes National Park, Hawaii.

Ferns are found on all continents except Antarctic and they are survivors from deep time.  Ferns range in size from tiny to tree, but all have a distinctive and elegant appearance that is quite appealing.