DragonflyPix

Grey Duskhawker (Gynacantha rosenbergi)

The Grey Duskhawker (Gynacantha rosenbergi) is a dragonfly species of the family Aeshnidae, which contains 13 species in Australia.

The identification key to the family Aeshnidae consists of 12 couplets, 7 of which are pertinent to Gynacantha rosenbergi. Click on the numbers on the right to display the corresponding couplets. Or click on the ALLin1 button to see all the relevant couplets together in a single, scrollable window.

#FamilySpeciesCouplet No.
 AeshnidaeGrey Duskhawker
(Gynacantha rosenbergi)
  • Aeshnidae: Key couplet 1 of 12

  • couplet drawing
    couplet drawingcouplet drawing
  • ● Prominent fork of IR3 near or proximal to level of basal end of pterostigma in both wings
    ● Anal margin of hindwing rounded in female, angulated in male, forming anal triangle
    ● Male with auricles
  • b ↑
  • Aeshnidae: Key couplet 5 of 12

  • couplet drawing
  • ● Space between CuP and 1A of hindwing slightly and continuously tapering from proximal to distal end, proximal portion usually one, occasionally two cells wide
  • a ↑
  • Aeshnidae: Key couplet 6 of 12

  • couplet drawingcouplet drawingcouplet drawing
  • ● Anal triangle of male broad or narrow, with three or more cells
    ● Dentigerous plate of female two-pronged
  • b ↑
  • Aeshnidae: Key couplet 7 of 12

  • couplet drawing
  • ● Front of synthorax dull brown or green, pale or dark, with or without an ill-defined pale patch in lower, outer corner
    ○ Abdominal segments 4-7 with, at most, small pale spots, often almost unpatterned

    ⇒ genus: Gynacantha
  • b ↑
  • Aeshnidae: Key couplet 8 of 12

  • couplet drawing
  • ● Top of frons with variably dark mid-dorsal line, commonly forming T-shaped mark with dark transverse mark on crest
  • b ↑
  • Aeshnidae: Key couplet 9 of 12

  • couplet drawingcouplet drawingcouplet drawing
  • ● Segment 3 less strongly constricted, width of 'waist' c. 1.3 mm or more in male, 1.8 mm or more in female
  • b ↑
  • Aeshnidae: Key couplet 11 of 12

  • couplet drawingcouplet drawingcouplet drawing
  • ● Width of male 'waist' on abdominal segment 3 1.8-2.3 mm
    ● 2-10 (commonly 3-7) black denticles along margin of genital fossa
    ● Ventral region of tergum 3 of female relatively broad, hind margin more than 1.3 mm

    ⇒ species: Grey Duskhawker (Gynacantha rosenbergi)
  • b ↑
1  
  • Aeshnidae: Key couplet 1 of 12

  • couplet drawing
    couplet drawingcouplet drawing
  • ● Last prominent fork of IR3 at or near level of distal end of pterostigma in both wings
    ● Margin of hindwing rounded in both sexes, male lacking anal triangle and auricles

    ⇒ genus: Anax
a ↑
b ↓
  • couplet drawing
    couplet drawingcouplet drawing
  • ● Prominent fork of IR3 near or proximal to level of basal end of pterostigma in both wings
    ● Anal margin of hindwing rounded in female, angulated in male, forming anal triangle
    ● Male with auricles

2  
  • Aeshnidae: Key couplet 5 of 12

  • couplet drawing
  • ● Space between CuP and 1A of hindwing slightly and continuously tapering from proximal to distal end, proximal portion usually one, occasionally two cells wide
a ↑
b ↓
  • couplet drawing
  • ● Space between CuP and 1A of hindwing two to three cells wide proximally, narrowing to half or less in width over central third

3  
  • Aeshnidae: Key couplet 6 of 12

  • couplet drawingcouplet drawing
  • ● Anal triangle of male narrow, two-celled
    ● Dentigerous plate of female three-pronged

    ⇒ species: Trifid Duskhawker (Agyrtacantha dirupta)
a ↑
b ↓
  • couplet drawingcouplet drawingcouplet drawing
  • ● Anal triangle of male broad or narrow, with three or more cells
    ● Dentigerous plate of female two-pronged

4  
  • Aeshnidae: Key couplet 7 of 12

  • couplet drawing
  • ● Front of synthorax with long, slanting pale stripe on each side
    ○ Abdominal segments 4-7 with prominent basal, central and apical pale, yellowish spots

    ⇒ species: Australian Duskhawker (Austrogynacantha heterogena)
a ↑
b ↓
  • couplet drawing
  • ● Front of synthorax dull brown or green, pale or dark, with or without an ill-defined pale patch in lower, outer corner
    ○ Abdominal segments 4-7 with, at most, small pale spots, often almost unpatterned

    ⇒ genus: Gynacantha

5  
  • Aeshnidae: Key couplet 8 of 12

  • couplet drawing
  • ● Top of frons with faint darkening in midline

    ⇒ species: Cave Duskhawker (Gynacantha nourlangie)
a ↑
b ↓
  • couplet drawing
  • ● Top of frons with variably dark mid-dorsal line, commonly forming T-shaped mark with dark transverse mark on crest

6  
  • Aeshnidae: Key couplet 9 of 12

  • couplet drawingcouplet drawingcouplet drawing
  • ● Segment 3 strongly constricted, width of 'waist' c. 1.1 mm or less in male, 1.5 mm in female
a ↑
b ↓
  • couplet drawingcouplet drawingcouplet drawing
  • ● Segment 3 less strongly constricted, width of 'waist' c. 1.3 mm or more in male, 1.8 mm or more in female

7  
  • Aeshnidae: Key couplet 11 of 12

  • couplet drawingcouplet drawingcouplet drawing
  • ● Width of male 'waist' on abdominal segment 3 1.3-1.8 mm
    ● 8-30 (commonly 15-25) black denticles around margin of genital fossa
    ● Ventral region of tergum 3 of female relatively narrow, hind margin from last tooth on lateral ridge to alignment of inner ridge less than 1.1 mm

    ⇒ species: Lesser Duskhawker (Gynacantha dobsoni)
a ↑
b ↓
  • couplet drawingcouplet drawingcouplet drawing
  • ● Width of male 'waist' on abdominal segment 3 1.8-2.3 mm
    ● 2-10 (commonly 3-7) black denticles along margin of genital fossa
    ● Ventral region of tergum 3 of female relatively broad, hind margin more than 1.3 mm

    ⇒ species: Grey Duskhawker (Gynacantha rosenbergi)

Australian distribution