British Insects: the Odonata
Annulatus (Latreille, 1804), nec (Fabricius 1798).
Adults. Adults about (70–)74–84(–88) mm long (the females considerably the longer). Average wingspan 101 mm; hindwings 41–46 mm long.
The eyes dorsally narrowly apposed (just meeting at a point); brown and green, or green.
Legs black. Thoracic antehumeral stripes present; yellow. 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 18–22 (fewer in the hindwings); incorporating two conspicuously stronger primaries, and those in the costal and subcostal spaces unaligned. Pterostigma narrow-linear; black.
Abdomen swollen both basally and distally and markedly constricted in between; 60–64 mm long (female), or 54–60 mm long (male); predominantly blackish brown to black; predominantly transversely banded (with conspicuous yellow bands, alternating broad and narrow, on the dark background); without mid-dorsal spots. The male abdomen auriculate on segment 2; with a single inferior anal appendage. The female with a relatively very long ovipositor.
Nymphs. The nymphs stout, the body expanded in the middle; when mature, 35–42 mm long.
The eyes lateral and widely separated on the top of the head. 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 narrowed gradually to the hinge; having the prementum hollowed dorsally; with the median lobe of the prementum shortly apiculate and bifid. The prementum bearing 8–10 major setae (4+4 to 5+5, with a field of small setae proximal to them). The body of the labial palps bearing 4–5 major setae (and sometimes one or two small setae anterior to them). Distal margins of the labial palps irregularly, coarsely toothed. 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, southern Scotland, northern England, English Midlands, Wales, southeast England, southwest England, Isle of Wight, and central southern England (scarce in the English Midlands, notably absent from East Anglia). Adults on the wing late may to early October (generally in best mature condition early June to mid-August).
Classification. Anisoptera; family Cordulegasteridae.
General comments. The female immediately distinguished from all other British dragonflies by its very long ovipositor.
Illustrations. • Cordulegaster boltonii (from Lucas). • Cordulegaster boltonii: nymph (from Lucas).
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’.