Stout Pintail, Acisoma inflatum, Dikpylstertjie.

100 1850 Male Tzaneen LP RSA Dec 2017r 3

100 1854 Male Tzaneen LP RSA Mch 2016r 7

100 1845 Female Tzaneen LP RSA Nov 2015r 2

Short description:

Stout Pintail, Acisoma inflatum, Dikpylstertjie is very small to small, mosaic bluish grey, greenish yellow and black, with bulbous (spindle shaped) abdomens that taper sharply at mid length, becoming black and ending in cream appendages..

Previously grouped with Acisoma variegatum (Slender Pintail) as one species,  Acisoma panorpoides (Grizzled Pintail).

Family Libellulidae Leach, 1815

More images

100 1855 Acisoma inflatum Stout Pintail Male1 Tzaneen LP RSA Nov 2015r 2Image
Gallery

100 1863 Acisoma inflatum Stout Pintail Male Hertzogberg MP Nov 2017r 1Male
Close-up

100 1869 Acisoma inflatum Stout Pintail Hertzogberg MP Nov 2017r 1Female
Close-up

100 2479 Acisoma inflatum Stout Pintail Male Hertzogberg MP Nov 2017f 1011Male
Annotated

 

 

 

 

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Key identification features:

Male:

  • Face has various light colours and black stripes. Labrum is cream with basal central black dot. Anteclypeus is pencil grey.
    Postclypeus is light blue. Frons has a black band in lower part, some black above and at sides and light blue centrally. Head is black above.100 1867 Acisoma inflatum Stout Pintail Male Hertzogberg MP Nov 2017r 6
  • Eyes are bright turquoise.
  • Thorax is light bluish grey, covered with myriad of irregular black lines and dots above and at sides.100 1864 Acisoma inflatum Stout Pintail Male Hertzogberg MP Nov 2017r 3
  • Wings are clear, with dark brown basil patch in hind wing. Pterostigmas are relatively long (3 mm), whitish, slightly transparent.
  • Abdomen underside of segments 1 to 3 bluish. Abdomen Segments 1 to 4 swollen, contrasting with segments 5 to 10 which are narrow.
    S 1 to 7 light bluish grey with black markings, including dorsal stripe. S 8 to 10 black. S 6 is 2½ x as long as high. S6 shorter in length than s7 100 2477 Acisoma variegatum Slender pintail Female Close up Skukuza MP RSA Febr 2018f 1411

Female:

  • Similar in shape as male but abdomen broader.
  • Young males and females similar
  • Pruinose to grey with very little detail visible with age
  • Eyes stray coloured greenish above with light greenish white below with light blue streaks.
  • Thorax (dorsal) and dorsal abdomen is straw coloured to greenish yellow with dark brown and blackish markings Thorax in lateral view greenish yellow above becoming light yellowish green becoming light whitish blue below. 100 1871 Acisoma inflatum Stout Pintail Hertzogberg MP Nov 2017r 3
  • Wings clear who. Basel amber patch. Pterostigmas light grey.
  • Abdomen underside of segments 1 to 3 bluish. Abdomen Segments 1 to 4 swollen, contrasting with segments 5 to 10 which are narrow. S 1 to 7 light bluish grey with black markings, including dorsal stripe. S 8 to 10 black. S 6 is 2½ x as long as high. S6 shorter in length than s7 100 2478 Hertzogberg MP Nov 2017f 511 Lateral abdomen carina all black
Habitat:
  • Occurs in swampy and well vegetated habitats along lakes, pools and slow parts of rivers and streams in Savannah and woodland.
Behaviour:

Their flight is almost wasp-like as it darts over the floating vegetation, frequently settling, usually at least a metre from the bank.

Compared with other species:
  • Acisoma variegatum (Slender Pintail) abdomen segment 6 is 3× as long as high (side View). S6 and s7 is approximately equal in length. (Male 100 2476 Male Close up Skukuza Sept 2018f 1111 Female 100 2477 Acisoma variegatum Slender pintail Female Close up Skukuza MP RSA Febr 2018f 1411)
  • A. inflatum (Stout Pintail) abdomen segment 6 is 2½ x as long as high. S6 is shorter than S7
  • A. inflatum has more extensive black markings on the abdomen than the A. variegatum
  • Side view the lower region of segment 4 is black in the A. inflatum but whitish in the A. variegatum (Male 100 2479 Male Hertzogberg MP Nov 2017f 1011 Female 100 2478 Acisoma inflatum Stout Pintail Hertzogberg MP Nov 2017f 511)
  • Despite marked differences in mature males, females and fresh males are less distinctly marked and may be confused
Distribution

Acisoma inflatum Stout Pintail Distribution Map May 2020Distribution Map
South Africa

Physical Map South Africa Physical Map
South Africa

Political Map South Africa Political Map
South Africa

Acisoma inflatum Stout Pintail Africa Distribution Map Feb 2021Distribution Map
Africa

Physical Map AfricaPhysical Map
Africa

Political Map AfricaPolitical Map
Africa

 

 

South Africa:

  • Northwards from KZN to MP, LP, and GP.

Africa:

  • Algeria; Angola; Benin; Botswana; Burkina Faso; Côte d'Ivoire; Cameroon; Chad; Congo-Brazzaville; Democratic Republic of the Congo; Egypt; Ethiopia; Gabon; Gambia; Ghana; Kenya; Liberia; Libya; Malawi; Nigeria; Republic of Guinea; Republic of South Africa; Senegal; Sierra Leone; Tanzania; Uganda; Zambia; Zimbabwe; NOT confirmed: Central African Republic; Equatorial Guinea; Guinee-Bissau; Mali; Mauritania; Namibia; South Sudan; Swaziland; Togo
Further reading:

Websites of Interest