Emperor dragonfly

The generic name Anax is from the ancient Greek {{lang|grc|ἄναξ}}, "lord";{{cite book |title=Etymological Dictionary of Greek |first=Robert |last=Beekes |author-link=Robert S. P. Beekes |others=With the assistance of Lucien van Beek |volume=1 |place=Leiden, Boston |publisher=Brill |year=2010 |orig-year=2009 |chapter=S.v. {{lang|grc|ἄναξ}} |pages=98–99 |isbn=978-900417-418-4}} the specific epithet imperator is the Latin for "emperor", from imperare, to command.{{cite web |title=imperator (n.) |url=https://www.etymonline.com/word/imperator |website=Online Etymology Dictionary |access-date=27 August 2021}}

This dragonfly has a wide distribution through Afroeurasia; it is found throughout Africa and through most of Europe, the Arabian Peninsula, and south-western and central Asia. Since the 1990s, its range has expanded in Europe, both northwards and to higher altitudes. For example, the first Scandinavian record was in 1994 in Denmark; in 2002 it was first recorded in Sweden and in 2004 first in Scotland; today it is regular in all three countries.{{cite journal |last1=Herzog |first1=Rebecca |last2=Osigus |first2=Hans−Jürgen |last3=Feindt |first3=Wiebke |last4=Schierwater |first4=Bernd |last5=Hadrys |first5=Heike |date=29 October 2016 |title=The complete mitochondrial genome of the emperor dragonfly Anax imperator LEACH, 1815 (Odonata: Aeshnidae) via NGS sequencing |journal=Mitochondrial DNA Part B |volume=1 |issue=1 |pages=783–786 |doi=10.1080/23802359.2016.1186523 |pmc=7799497 |pmid=33473626 |s2cid=89088747 |doi-access=free}} The species' northward expansion has been tied to global warming, and it is among the first odonata to do so.

The emperor dragonfly is a large and bulky species. It is {{cvt|73-82|mm}} long, with average being {{cvt|78|mm}} and males growing larger than females.{{cite web| title=Anax imperator (Leach, 1815) | url=https://www.delta-intkey.com/britin/odo/www/imperato.htm | publisher=Insects of Britain and Ireland: dragonflies and damselflies (Odonata)| access-date=25 November 2023 }} The average wingspan is {{cvt|104|mm}}. When they first emerge, both sexes appear pale green with brown markings. The legs are brown with a yellow like base. Wings are born black but grow yellow-brown when they grow. Males have a bright sky blue or turquoise abdomen marked with a diagnostic black dorsal stripe. However, their blue colour may be faded during cold weather spells. The thorax and head of a male is apple green and their prominent eyes are blue. Females have similar markings but they are mainly a duller green. As the females age, their wings become browner. Less immediately visible features for both sexes are the yellow costa and brown spots on the wings. Emperor dragonflies can also be recognised by their flight patterns: they often fly with their abdomen hanging slightly downwards.

One of the largest species in Europe, the emperor dragonfly is exceeded by magnificent emperor, which occurs only marginally in the east Mediterranean{{cite web |title=Anax immaculifrons Rambur, 1842 – Magnificent Emperor |url=https://dragonflies.online/true-dragonflies-anisoptera/aeshnidae-hawkers-or-darners/anax-immaculifrons-magnificent-emperor/ |access-date=25 November 2023 |publisher=Dragonflies and Damselflies – in and around Europe}} and in length by females of the golden-ringed dragonfly, a species with an unusually long ovipositor.{{cite web |title=Golden-ringed Dragonfly |url=https://british-dragonflies.org.uk/species/golden-ringed-dragonfly/ |access-date=25 November 2023 |publisher=British Dragonfly Society}} Thus, in most of Europe the emperor is the largest dragonfly species present.

File:Ai(loz)hydro.JPG|Male in side view

File:Anax imperator 2015 11 23 6807 (cropped).jpg|Male in flight

File:Anax imperator female.jpg|Female laying eggs

File:Anax imperator Exuvie MHNT Parc de la Maourine.jpg|Exuviae

File:Anax Imperator 2(loz).JPG|Emerging

They frequently fly high up into the sky in search of prey, which includes butterflies, other odonata and tadpoles. If their hunt is successful, they eat their smaller prey while flying. The dragonflies breed in a variety of aquatic habitats from large ponds to dikes and slow-moving rivers, but require a plentiful supply of vegetation in the water.{{Cite web |title=Emperor Dragonfly |url=http://www.lincstrust.co.uk/species/drgnfly/ed/ed.html |url-status=dead |archive-url=https://web.archive.org/web/20031025041222/http://www.lincstrust.co.uk/species/drgnfly/ed/ed.html |archive-date=25 Oct 2003 |website=Lincolnshire Species}} They do sometimes breed in brackish water.{{Cite book |last1=Smallshire |first1=Dave |url=https://books.google.com/books?id=yfqwDwAAQBAJ&dq=%22blue+emperor%22+%22dragonfly:&pg=PA166 |title=Europe's Dragonflies: A field guide to the damselflies and dragonflies |last2=Swash |first2=Andy |date=2020-07-14 |publisher=Princeton University Press |isbn=978-0-691-20497-0 |language=en}} The females lay the eggs into plants such as pondweed, and always lay alone. The aquatic larvae are very aggressive and are likely to influence the native species composition of freshwater ecosystems they arrive in. The larvae are also very large–around {{Convert|46|mm|in}}.{{Cite journal |last1=Minot |first1=Marceau |last2=Le Gall |first2=Mickael |last3=Huste |first3=Aurelie |date=2019-09-10 |title=Biometry of the large dragonfly Anax imperator (Odonata: Aeshnidae): A study of traits from larval development to adults |url=http://www.eje.cz/doi/10.14411/eje.2019.031.html |journal=European Journal of Entomology |volume=116 |pages=269–280 |doi=10.14411/eje.2019.031}} The adult male is highly territorial, and difficult to approach.{{cite web |url=http://www.arkive.org/emperor-dragonfly/anax-imperator/ |title=Emperor dragonfly videos, photos and facts — Anax imperator |publisher=ARKive |access-date=2013-08-08 |archive-url=https://web.archive.org/web/20150409013006/http://www.arkive.org/emperor-dragonfly/anax-imperator/ |archive-date=2015-04-09 |url-status=dead }}

Emperor dragonflies are assessed as a least-concern species by the IUCN. The species has widespread and has a stable population.

The mitogenome of the emperor dragonfly is the longest of all known dragonfly sequences. It has 16,087 base pairs. For comparison, the human mitogenome has 16,569 {{Abbr|bp|base pairs}}{{Cite journal |last1=García-Olivares |first1=Víctor |last2=Muñoz-Barrera |first2=Adrián |last3=Lorenzo-Salazar |first3=José M. |last4=Zaragoza-Trello |first4=Carlos |last5=Rubio-Rodríguez |first5=Luis A. |last6=Díaz-de Usera |first6=Ana |last7=Jáspez |first7=David |last8=Iñigo-Campos |first8=Antonio |last9=González-Montelongo |first9=Rafaela |last10=Flores |first10=Carlos |date=2021-10-15 |title=A benchmarking of human mitochondrial DNA haplogroup classifiers from whole-genome and whole-exome sequence data |journal=Scientific Reports |language=en |volume=11 |issue=1 |pages=20510 |doi=10.1038/s41598-021-99895-5 |pmid=34654896 |issn=2045-2322|pmc=8519921 |bibcode=2021NatSR..1120510G }} and the closely related dragonfly Anax parthenope has 15,366.{{Cite journal |last1=Wang |first1=Ying |last2=Du |first2=Yimin |last3=Song |first3=Xiang |last4=Huang |first4=Aijun |date=2021-01-02 |title=Complete mitochondrial genome sequence of Anax parthenope (Odonata: Anisoptera: Aeshnidae) and phylogenetic analysis |journal=Mitochondrial DNA Part B |language=en |volume=6 |issue=1 |pages=122–123 |doi=10.1080/23802359.2020.1848479 |issn=2380-2359 |pmc=7808743 |pmid=33490598}}

{{Reflist|30em}}

• [http://thebdi.org/2020/01/30/blue-emperor-anax-imperator/ Blue Emperor] Species text in the Online Atlas of South African Odonata
• {{Commons-inline}}

{{Taxonbar|from=Q527496}}

Category:Aeshnidae

Category:Odonata of Africa

Category:Odonata of Asia

Category:Dragonflies of Europe

Category:Insects described in 1815

Category:Taxa named by William Elford Leach