Keyhole Glide,Tramea basilaris, Loerswerwer
Short description:
Keyhole Glide, Tramea basilaris, Loerswerwer is fairly large sized with a tapered abdomen, orange red and brown, with black abdominal tip. Hind wings have jiggered, dark red, basil patches with amber halo.
Family Libellulidae Leach, 1815
Also known as Red Marsh Trotter, Wheeling Glider
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Key identification features:
- Face is reddish to light and dark brown. Post frons red. Postclypeus reddish. Anticlupeus white above brown below. Labrum brown becoming dark brown/black towards the lower margin
- Eyes are dark red above and greyish with dark mottles below
- Thorax is brown above with greenish brownish patches on brownish to greenish grey. Lower thorax and segments 1 - 3, including male secondary genitalia, covered with fine white hair
- Wings are elongated, with large jiggered, dark red, basil patches with amber halo on the hindwing
- Pterostigmas are yellowish brown with the ones on the fore wing the longer (3mm - 2mm)
- Segment 1 dark brown, s 2 to 7 light red. S 8 with triangular black patch above, s 9 - 10 black above. Segments 8 - 10 with fine cream lines along hind margins
- Superior appendages long, dark brown with slight base with slight outward curve
- Similar in body patterning but yellowish brown instead of reddish
- Thorax covered with fine white hair
- Wing patches similar but brown rather than dark red. Extent of the two lobes varies from female to female and with age. The lobe may be wide open or closed to form the keyhole
- Long dark brown claspers, that points slightly outwards in the male
- Superior appendages long, dark brown with light base with slight outward curve
Habitat:
- Keyhole Glide, Tramea basilaris, Loerswerwer Breeds in standing and often temporary waters in open landscapes, but sometimes shaded by gallery forest. Often with coarse detritus and a soft (like muddy) bottom
- From 0 to 1800 m above sea level
Behaviour:
- Males fly between bushes and trees continuously for long periods. may chase other species at a pond.
- They range from close to water to quite a distance away from the breeding waters. Male will hold female, fly down to the water and monetarily release her while she plash the eggs onto the water in a forward motion.
- Male grabs female as soon as oviposit is completed and flies of to another position to oviposit again
Compared with other species:
- Ferruginous Glider, T. limbata, has elongated dark shaped markings in the hindwing
- In flight, the patterns on the hind wings are diagnostic on both species
- Similar to the Blue Basker, U. edwardsii, but different in colour.
- Can be mistaken for the Gliders (Keyhole and Ferruginous), Tramea basilaris and Tramea limbata. The Red Basker has bigger patches than the Ferruginous Glider and the Keyhole Glider has keyhole shaped patches.
- There are several red coloured species that needs close inspection to identify correctly.
- Aethriamanta rezia, Pygmy Basker: Very small. Eyes brown with red cap on top, mottled grey below. Thorax with black shoulder stripe. Legs black. Wings all with small dark brown flares at the base, hind wings with additional small patch just behind flares, flares are surrounded by amber halo. 6 Ax veins. Pterostigmas reddish brown 2mm. Abdomen wide, bright red with regular black ladder running along entire top. Segment 1 blackish. Superior appendages red.
- Urothemis assignata, Red Basker: Stout, bright red. Eyes deep red above, mottled dark and light grey below. Legs light red. Hind wings have large dark red angular basal patches with amber hallow. Fore wing has small traces of amber at the base. Wing veins red. Pterostigma yellow brown 4mm. Last Ax vein complete. Abdomen segments 5 -9 have black above with median ladder-like stripe of uneven width, widest on s 8 - 9. Appendages of moderate length, red.
- Macrodiplax cora. Coastal Pennant: Wings clear, except for small amber patch at base of hind wings. Abdomen bright red with along top strongly contrasting black hour glass shaped stripe of varying width, broken at each segment joint.
- Tramea basilaris, Keyhole Glider, Hind wing patches distinctive keyhole shaped. Thorax dull orange above dark brownish grey with dark brown areas along the side. Abdomen segment 8 triangular shaped mark, S 9 -10 black above. Superior appendages long, dark brown with light base.
- Tramea limbata, Ferruginous Glider, Hind wing patches distinctive elongated, narrow shaped dark panels close to basel edge of the wing that may appear black in flight. long brown claspers
- Tholymis tillarga, Twister. Hind wings with dark brown patch just inside nodus in front half, with white patch outside of it and diffuse amber area inside it. Fore wings with diffuse amber area at bases of wings. Abdomen tapered, light red. Appendages long, red, black at tips.
- Aethriamanta rezia, Pygmy Basker: Very small. Eyes brown with red cap on top, mottled grey below. Thorax with black shoulder stripe. Legs black. Wings all with small dark brown flares at the base, hind wings with additional small patch just behind flares, flares are surrounded by amber halo. 6 Ax veins. Pterostigmas reddish brown 2mm. Abdomen wide, bright red with regular black ladder running along entire top. Segment 1 blackish. Superior appendages red.
Distribution:
South Africa:
- Flies in warm, humid areas. Found in Gauteng, Limpopo, FP, Mpumalanga KZN. Not enough data for NWP, NCP to have a clear distribution picture. Some present in the Western Cape
Africa:
- Angola; Benin; Botswana; Burkina Faso; Côte d'Ivoire; Cameroon; Central African Republic; Chad; Congo-Brazzaville; Democratic Republic of the Congo; Equatorial Guinea; Ethiopia; Gabon; Gambia; Ghana; Guinee-Bissau; Kenya; Liberia; Malawi; Mali; Mauritania; Mozambique; Namibia; Niger; Nigeria; Republic of South Africa; Rwanda; São Tomé & Príncipe; Senegal; Sierra Leone; Socotra (Yemen); Somalia; Swaziland; Tanzania; Togo; Uganda; Zambia; Zimbabwe
Further reading:
Websites:
- Odonata Atlas of Africa Number 668620
- A Visual Guide to the Damselflies and Dragonflies of South Africa
- The IUCN Red List of Threatened Species Least Concern
- African Dragonflies & Damselflies Online