DragonflyPix

Large Riverdamsel (Caliagrion billinghursti)

The Large Riverdamsel (Caliagrion billinghursti) is a damselfly species of the family Coenagrionidae, which contains 30 species in Australia.

The identification key to the family Coenagrionidae consists of 54 couplets, 14 of which are pertinent to Caliagrion billinghursti. 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.
 CoenagrionidaeLarge Riverdamsel
(Caliagrion billinghursti)
  • Coenagrionidae: Key couplet 1 of 54

  • ○ Damselflies without this combination of characters
  • b ↑
  • Coenagrionidae: Key couplet 14 of 54

  • couplet drawing
  • ● Anal vein leaving wing margin well basal to the level of Ac in both wings, so there is a basal segment of anal vein about the same length as Ac
  • a ↑
  • Coenagrionidae: Key couplet 14 of 54

  • couplet drawing
  • ● Anal vein leaving wing margin nearer to or beyond level of Ac
    ● Basal segment of hindwing anal vein, if present, not more than half length of Ac
  • b ↑
  • Coenagrionidae: Key couplet 15 of 54

  • ○ Hindwing longer than 22 mm
  • a ↑
  • Coenagrionidae: Key couplet 16 of 54

  • ○ Abdominal segments 2-4 black and blue or blue-grey above

    ⇒ species: Large Riverdamsel (Caliagrion billinghursti) (part)
  • a ↑
  • Coenagrionidae: Key couplet 35 of 54

  • ○ Damselflies with dark brown or black markings on pale background (reddish, yellow, green, blue, pale brown), or substantially dark, the dark areas in either case often with metallic sheen
  • b ↑
  • Coenagrionidae: Key couplet 37 of 54

  • couplet drawingcouplet drawing
  • ● Pterostigma of forewing similar in size to that of hindwing
    ● Female lacking ventral spine on abdominal segment 8
  • b ↑
  • Coenagrionidae: Key couplet 38 of 54

  • couplet drawing
  • ● Pterostigma markedly longer than wide
  • b ↑
  • Coenagrionidae: Key couplet 40 of 54

  • ○ No such markings on thorax or abdomen
  • b ↑
  • Coenagrionidae: Key couplet 41 of 54

  • ○ Synthorax blue and black
  • b ↑
  • Coenagrionidae: Key couplet 42 of 54

  • couplet drawing
  • ● Antealar sinus partially to substantially blue
  • a ↑
  • Coenagrionidae: Key couplet 43 of 54

  • couplet drawing
  • ● Ac of hindwing aligned, or almost aligned, with basal antenodal crossvein

    ⇒ species: Large Riverdamsel (Caliagrion billinghursti) (part)
  • a ↑
  • Coenagrionidae: Key couplet 48 of 54

  • couplet drawing
  • ● Posterior lobe of pronotum with forwardly directed, finger-like process on each side
  • a ↑
  • Coenagrionidae: Key couplet 49 of 54

  • couplet drawing
  • ● Ac of hindwing aligned with basal antenodal crossvein

    ⇒ species: Large Riverdamsel (Caliagrion billinghursti) (part)
  • a ↑
1  
  • Coenagrionidae: Key couplet 1 of 54

  • couplet drawing
  • ● Arculus in hindwing situated beyond distal antenodal crossvein by at least the length of subcostal part of antenodal
    ○ Very small damselflies, hindwing shorter than 14 mm

    ⇒ genus: Agriocnemis
a ↑
b ↓
  • ○ Damselflies without this combination of characters

2 (part)
  • Coenagrionidae: Key couplet 14 of 54

  • couplet drawing
  • ● Anal vein leaving wing margin well basal to the level of Ac in both wings, so there is a basal segment of anal vein about the same length as Ac
a ↑
b ↓
  • couplet drawing
  • ● Anal vein leaving wing margin nearer to or beyond level of Ac
    ● Basal segment of hindwing anal vein, if present, not more than half length of Ac

3 (part)
  • Coenagrionidae: Key couplet 14 of 54

  • couplet drawing
  • ● Anal vein leaving wing margin well basal to the level of Ac in both wings, so there is a basal segment of anal vein about the same length as Ac
a ↑
b ↓
  • couplet drawing
  • ● Anal vein leaving wing margin nearer to or beyond level of Ac
    ● Basal segment of hindwing anal vein, if present, not more than half length of Ac

4  
  • Coenagrionidae: Key couplet 15 of 54

  • ○ Hindwing longer than 22 mm
a ↑
b ↓
  • ○ Hindwing shorter than 22 mm

5 Male only
  • Coenagrionidae: Key couplet 16 of 54

  • ○ Abdominal segments 2-4 black and blue or blue-grey above

    ⇒ species: Large Riverdamsel (Caliagrion billinghursti) (part)
a ↑
b ↓
  • ○ Abdominal segments 2-4 bronze-black above

    ⇒ genus: Pseudagrion

6  
  • Coenagrionidae: Key couplet 35 of 54

  • ○ Orange-red to yellowish green damselflies without dark thoracic markings
a ↑
b ↓
  • ○ Damselflies with dark brown or black markings on pale background (reddish, yellow, green, blue, pale brown), or substantially dark, the dark areas in either case often with metallic sheen

7  
  • Coenagrionidae: Key couplet 37 of 54

  • couplet drawingcouplet drawing
  • ● Pterostigma of forewing markedly larger than that of hindwing
    ● Female with ventral spine on apex of abdominal segment 8

    ⇒ species: Blue Slim (Aciagrion fragile)
a ↑
b ↓
  • couplet drawingcouplet drawing
  • ● Pterostigma of forewing similar in size to that of hindwing
    ● Female lacking ventral spine on abdominal segment 8

8  
  • Coenagrionidae: Key couplet 38 of 54

  • couplet drawing
  • ● Pterostigma very small, almost as long as wide

    ⇒ species: Blue-Banded Longtail (Archibasis mimetes)
a ↑
b ↓
  • couplet drawing
  • ● Pterostigma markedly longer than wide

9 Male only
  • Coenagrionidae: Key couplet 40 of 54

  • ○ Extensive dull orange to red markings on head, thorax and anterior abdomen

    ⇒ species: Red & Blue Damsel (Xanthagrion erythroneurum)
a ↑
b ↓
  • ○ No such markings on thorax or abdomen

10 Male only
  • Coenagrionidae: Key couplet 41 of 54

  • ○ Synthorax with extensive brown or yellow areas, sometimes pruinescent

    ⇒ genus: Pseudagrion
a ↑
b ↓
  • ○ Synthorax blue and black

11 Male only
  • Coenagrionidae: Key couplet 42 of 54

  • couplet drawing
  • ● Antealar sinus partially to substantially blue
a ↑
b ↓
  • ○ Antealar sinus black

12 Male only
  • Coenagrionidae: Key couplet 43 of 54

  • couplet drawing
  • ● Ac of hindwing aligned, or almost aligned, with basal antenodal crossvein

    ⇒ species: Large Riverdamsel (Caliagrion billinghursti) (part)
a ↑
b ↓
  • couplet drawing
  • ● Ac of hindwing beyond alignment of basal antenodal crossvein

    ⇒ genus: Pseudagrion

13 Female only
  • Coenagrionidae: Key couplet 48 of 54

  • couplet drawing
  • ● Posterior lobe of pronotum with forwardly directed, finger-like process on each side
a ↑
b ↓
  • couplet drawing
  • ● Posterior lobe of pronotum without forwardly directed, finger-like process on each side

14 Female only
  • Coenagrionidae: Key couplet 49 of 54

  • couplet drawing
  • ● Ac of hindwing aligned with basal antenodal crossvein

    ⇒ species: Large Riverdamsel (Caliagrion billinghursti) (part)
a ↑
b ↓
  • couplet drawing
  • ● Ac of hindwing beyond alignment with basal antenodal crossvein

    ⇒ genus: Pseudagrion

Australian distribution