Black Emperor, Anax tristis, Swartkeiser  

Short description:

Black Emperor Anax tristis Swartkeiser is very large sized, green thorax and mostly black abdomen with cream spots on the side and a distinctive cream ring at the base of abdomen.

Family Aeshnidae Leach, 1815

Also known as Magnificent Emperor

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Key identification features:

Male:

• Face all light to greenish blue with blackish basal triangle on top of frons.
• Eyes bright blue above, greenish blue below.
• Thorax green with two turquoise green patches between wings.
• Wings clear becoming  slightly smoky particularly in central areas, dark brown spot beside membranule. Pterostigmas long (5 mm), reddish brown.
• Abdomen and appendages mostly black. Segment 1 with cream dorsal patch, segment 2 with wide cream ring running all the way around. Segments 4 to 9 with small cream spots above. Segment 10 black.

Female:

• Similar to male but stouter, shorter, appendages shorter and leaf-like, wings generally fairly smoky
• Face with yellow and green with black dot on upper surface of nose
• Eyes olive, thorax light to mid green
• Wings slightly smoky becoming smoky with age, pterostigmas long (5 mm) and reddish brown, segment 1 yellowish green, segment 2 mostly pale blue, segment 3 pale blue below, majority of rest of abdomen dark brown with some light greenish to blue patches on sides.

Habitat:

• Frequents pools, small dams and waterholes in open or savanna areas. Such pools and swamps may be without water weed or fringing vegetation.
• From 0 to 2100 m above sea level, but mostly below 1600.

Behaviour:

• Flies low at great speed or unhurried, drifting low and slowly across and around pools. Sometimes cruises at tree top level.

Compared with other species:

• Unmistakable due to size and markings.
• The largest Emperor in South Africa.

Related Species

Distribution:

 South Africa:

•  Black Emperor Anax tristis Swartkeiser is found in the warm northern and eastern areas of South Africa.

Africa:

• Angola; Benin; Botswana; Burundi; Côte d'Ivoire; Cameroon; Cape Verde; Central African Republic; Chad; Congo-Brazzaville; Democratic Republic of the Congo; Equatorial Guinea; Gabon; Gambia; Ghana; Kenya; Liberia; Malawi; Mozambique; Namibia; Nigeria; Republic of South Africa; Rwanda; Sudan;Tanzania; Togo; Uganda; Zambia; Zimbabwe;

Further reading:

Websites:

•    A Visual Guide to the Damselflies and Dragonflies of South Africa
•    Odonata Atlas of Africa VMU Number 664180
• African Dragonflies & Damselflies Online
•   The IUCN Red List of Threatened Species    Least Concern