Long Skimmer,Orthetrum trinacria, Gestrekte Skepper
Long Skimmer, Orthetrum trinacria, Gestrekte Skepper is large, with deep pruinescent blue thorax and elongated abdomen with either distinctive pale or dark brown markings or notably dark pruinosity
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Key identification features:
- Length 51 - 55 - 58mm, wingspan 72 - 78 - 86mm, pterostigmas 4 - 4.5mm
- Eyes are dull turquoise, becoming brownish below
- Uniformly dark blue-black colour (darker than most other Skimmers in the region) Does not pruinose
- Large in size with long tapered abdomen, narrowing to a cola bottle shape at s 8. Long claspers
- Yellow becoming brown stripes on the side of the abdomen darkening to almost invisible with age. No markings on s 8-10
- Teneral males are similar to females
- Yellowish green thorax with yellow shaped (s 5-6 distinctly anvil shaped) markings on the abdomen. S 9-10 yellow on side of abdomen
- This pattern is also visible on young males but will darken to deep brown to almost invisible with age.
- Frequents the grassy margins of open water (dams, lakes, pans small shallow dams, sometimes along the grassy margins of streams.)
- From 0 to 1900 m above sea level, but mostly below 1500.
- Perches on the ground, low grass and reeds along the edge of the water. A strong flyer that hunts large insects, including butterflies and dragonflies.
Compared with other species:
- The slender abdomen distinguish O. trinacria from the other blue Dropwings, O. furva (Navy Dropwing), O. dorsalis (Highland Dropwing) and O. donaldsoni (Denim Dropwing)
- Robust Skimmer (Orthetrum robustum) is lighter grey and have different shaped abdominal markings.
- Halfshade Dropwing (T. aconita) is very similar and is identified by the number of Ax veins in the fore wing (10½ -12½) and (8½ - 9½) in Silhouette Dropwing (Trithemis hecate)
- Orthetrum trinacria eyes dull turquoise, becoming brownish below, T. hecate deep purplish brown, T. aconita deep purplish brown with whit at hind margin.
- Habitat can be used as identification aid. O. trinacria frequents the grassy margins of open water. T. hecate standing water and open marches. T. aconita standing waters, rivers and streams shaded by gallery forest, but also in open areas in forest
- Final confirmation however of males, must preferably be done by examination of secondary genitalia and measurements
- Common across large parts South Africa but not yet recorded from the western central dry areas.
- Algeria; Angola; Botswana; Burkina Faso; Côte d'Ivoire; Cameroon; Cape Verde; Democratic Republic of the Congo; Egypt; Ethiopia; Gabon; Gambia; Ghana; Guinee-Bissau; Kenya; Liberia; Libya; Malawi; Mali; Mauritania; Morocco; Mozambique; Namibia; Niger; Nigeria; Republic of South Africa; Rwanda; Senegal; Somalia; South Sudan; Swaziland; Tanzania; Togo; Tunisia; Uganda; Zambia; Zimbabwe;