The green darner or common green darner (''Anax junius''), after its resemblance to a darning needle, is a species of

dragonfly A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threat ...

in the family

Aeshnidae Aeshnidae, also called aeshnids, hawkers, or darners, is a family of dragonflies, found nearly worldwide, with more than 50 genera and over 450 species. The family includes some of the largest dragonflies. Description Common worldwide or nearl ...

. One of the most common and abundant species throughout

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, it also ranges south to

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

. It is well known for its great migration distance from the northern

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

south into

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

and

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. It also occurs in the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

Tahiti Tahiti (; Tahitian language, Tahitian , ; ) is the largest island of the Windward Islands (Society Islands), Windward group of the Society Islands in French Polynesia, an overseas collectivity of France. It is located in the central part of t ...

, and

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

from

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

to mainland

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. It is the official insect for the state of

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

in the

. The green darner is a large dragonfly; males grow to in length with a wingspan up to . Females oviposit in aquatic vegetation, eggs laid beneath the water surface.

Nymphs A nymph (; ; sometimes spelled nymphe) is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature; they are typically tied to a specific place, land ...

(naiads) are aquatic carnivores, feeding on

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

tadpole A tadpole or polliwog (also spelled pollywog) is the Larva, larval stage in the biological life cycle of an amphibian. Most tadpoles are fully Aquatic animal, aquatic, though some species of amphibians have tadpoles that are terrestrial animal, ...

s, and small

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

. Adult darners catch insects on the wing, including

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

alates,

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

mosquito Mosquitoes, the Culicidae, are a Family (biology), family of small Diptera, flies consisting of 3,600 species. The word ''mosquito'' (formed by ''Musca (fly), mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mos ...

es, and

flies Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...

Taxonomy

Dru Drury Dru Drury (4 February 1725 – 15 January 1804) was a British collector of natural history specimens and an entomologist. He received specimens collected from across the world through a network of ship's officers and collectors including Henry ...

described this species as ''Libellula junius'' in 1773. There are not currently any recognized subspecies. There are three recognized synonyms: ''Anax spiniferus'' Rambur, 1842; ''Anax ocellatus'' Hagen, 1867; ''Anax severus'' Hagen, 1867.

Distribution

Common green darners are commonly found throughout the continental United States and southern Canada, occasionally ranging as far south as Panama, particularly in the winter. There are also populations in Hawaii and the Caribbean. Vagrant individuals have been seen far outside of their normal range including sightings in Alaska, Russia, China, Japan, France, the United Kingdom, India, and Bermuda. These vagrant sightings are likely migrating individuals blown off-course by strong winds or storms.

Characteristics

Common green darners are large dragonflies, ranging from in length and a wingspan of up to . Both sexes have an unmarked green thorax. Mature males have bluish-purple abdomens (the first few abdominal segments are the brightest) with a black dorsal stripe that broadens near the end of the abdomen. Immature males and most females have reddish-brown abdomens, but some females are patterned like adult males. Wings are initially clear but usually become amber-tinted with age, especially in females. Both sexes have a black ‘bulls-eye’ mark on the face (more precisely, the

frons Insect morphology is the study and description of the physical form of insects. The terminology used to describe insects is similar to that used for other arthropods due to their shared evolutionary history. Three physical features separate insec ...

) in front of their eyes, a distinguishing field mark that separates them from the superficially similar comet darner ('' Anax longipes''). This species oviposits in tandem which is a unique behavior among North American darners.

Natural history

Diet and predators

Both the adult and the nymphal stage are predators.

prey upon immature aquatic insects (including conspecifics), small crustaceans, small tadpoles, and even small fish. Adults primarily prey on winged insects, including wasps, flies, butterflies, and other Odonates. The primary predators of common green darner nymphs are fish. Adults are preyed upon by birds and occasionally robber flies, spiders, and other large dragonflies.

Habitat

Nymphs develop in lakes, ponds, and slow streams and rivers. Adults are most frequently seen around nymph habitat but they are strong fliers and can be found in a wide variety of habitats including grasslands, forests, and urban areas.

Migration

There are several species of migratory dragonflies in North America, but common green darners are the best studied. Other migratory species include: * '' Tramea lacerata'' (black saddlebags) * ''

Pantala flavescens ''Pantala flavescens'', the globe skimmer, globe wanderer or wandering glider, is a wide-ranging dragonfly of the family Libellulidae. This species and ''Pantala hymenaea'', the "spot-winged glider", are the only members of the genus ''Pantala'' ...

'' (wandering glider) * '' Pantala hymenea'' (spot-winged glider) * ''

Sympetrum corruptum The variegated meadowhawk (''Sympetrum corruptum'') is a dragonfly of the family Libellulidae, native to North America. Description The variegated meadowhawk is a small to medium-sized dragonfly with a slender abdomen, often reaching a length ...

'' (variegated meadowhawk) The large geographic range and migratory behavior of the common green darner has made it a challenge to piece together its complex life history. Recent research has indicated that the annual life cycle of ''Anax junius'' is likely composed of at least three different generations. The first generation emerges in the southern end of its range in early spring and migrates northwards through spring and summer. The second generation emerges in the northern end of its range in summer and migrates southwards in fall. The third generation occurs in the south during the winter and does not migrate. Common green darners migrate in fall and spring but for several reasons the southward movement in fall is more noticeable. By attaching micro-radio transmitters to common green darners, researchers have found them to be capable of migrating up to in a day, though they typically cover less distance per day. A group of researchers used

stable isotope analysis Isotope analysis is the identification of isotopic signature, abundance of certain stable isotopes of chemical elements within organic and inorganic compounds. Isotopic analysis can be used to understand the flow of energy through a food web ...

on individuals collected between Ontario and Mexico during fall and documented that >90% of individuals moved southward, with an average distance of 900 kilometers. A study published in 2019 attached miniaturized radio transmitters to common green darners in the Great Lakes region and tracked their movement with the Motus Wildlife Tracking System. Individuals moved at an average groundspeed of .

Gallery

File:Img 041538 mating anax junius.jpg, Mating, wheel position File:Anax_junius-Laying_eggs-2.jpg, Egg-laying File:Dragonfly_Common_Green_Darner_Female_Anax_junius_2010-04-18.jpg, Female File:Common Green Darner, female.jpg, Uncommon blue form female, Ottawa, Canada File:Anax junius-hovering.jpg, Hovering San Joaquin Wildlife Sanctuary

References

External links

{{Taxonbar, from=Q175808 Aeshnidae Odonata of Asia Odonata of North America Insects of the Dominican Republic Symbols of Washington (state) Insects described in 1773 Taxa named by Dru Drury