British Insects: the Odonata
Southern Hawker Dragonfly.
Adults. Adults about 65–70–75 mm long. Average wingspan 100 mm; hindwings 43–50 mm long.
The eyes dorsally broadly contiguous; brown and green, or brown and blue.
Legs brownish black, or black and yellow (the undersides of the front femora yellowish). Thoracic antehumeral stripes present (these broad); apple green. The wings spread more or less horizontally in repose; dissimilar in shape and venation; sessile; unpatterned and clear. The inner wing venation blackish. Discoidal cell divided longitudinally into a conspicuous triangle and supra-triangle. Antenodal veins in the forewings about 20–22 (fewer in the hindwings); incorporating two conspicuously stronger primaries, and those in the costal and subcostal spaces unaligned. Pterostigma elongated but only about about twice as long as wide; black (in the male), or dark brown (in the female).
Abdomen linear from a conspicuously swollen base (less basally swollen in the female, and briefly somewhat constricted adjoining the swelling in the male); 52–58 mm long (female), or 51–60 mm long (male); predominantly dark brown (with green and yellow or green, yellow and blue markings); complexly patterned (spotted and banded with green and yellow, and with complete bands on segments 9 and 10 which are blue in the male and green in the female); with a conspicuous, median yellow triangle on segment 2; with mid-dorsal spots. Abdominal segments 9 and 10 exhibiting complete bands. The male abdomen auriculate on segment 2; with a single inferior anal appendage.
Nymphs. The nymphs stout, the body expanded in the middle; when mature, 38–48 mm long.
The eyes large; approaching one another closely at a point on the top of the head; convex dorsally, their posterior margins not aligned. The head in dorsal view not markedly narrowing from immediately behind the eyes. The postocular lobes curving sharply to the back of the head from some distance behind the eyes. The antennae 7 segmented. The mask shortly abruptly narrowed well before the hinge, with the prementum stalked to narrowed gradually to the hinge (the prementum relatively elongated). The prementum quite elongated, being nearly twice as long as the width of its front. The mask with a flat prementum; with a short slit-like median cleft. The prementum bearing 0 major setae. The body of the labial palps bearing 0 major setae. Distal margins of the labial palps entire. Legs shorter than the abdomen; fore- and middle tarsi 3-segmented.
The abdomen terminating in five short spine-like appendages; gizzard with 4–8 folds.
Distribution. Northern Scotland, northern England, English Midlands, East Anglia, Wales, southeast England, southwest England, Isle of Wight, and central southern England (less common further north, rare in Scotland). Adults on the wing early June to late October (generally in best mature condition late July to late September).
Classification. Anisoptera; family Aeshnidae.
Illustrations. • Aeshna cyanea (from Lucas). • Aeshna cyanea, female: photo, Giles Watson. • Aeshna cyanea emerging from nymph: Shipley 196. • Aeshna cyanea (from Shaw and Nodder, 1800).
To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: Dragonglies and Damselflies (Odonata). Version: 1st January 2012. http://delta-intkey.com’.