DragonflyPix

Twister (Tholymis tillarga)

The Twister (Tholymis tillarga) is a dragonfly species of the family Libellulidae, which contains 56 species in Australia.

The identification key to the family Libellulidae consists of 67 couplets, 6 of which are pertinent to Tholymis tillarga. 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.
 LibellulidaeTwister
(Tholymis tillarga)
  • Libellulidae: Key couplet 1 of 67

  • couplet drawing
  • ● Distal antenodal of forewing incomplete, only the costal section present
  • b ↑
  • Libellulidae: Key couplet 35 of 67

  • couplet drawing
  • ● Hindwing triangle free
  • b ↑
  • Libellulidae: Key couplet 39 of 67

  • ○ Not as above
  • b ↑
  • Libellulidae: Key couplet 40 of 67

  • couplet drawing
  • ● Base of hindwing triangle at or slightly proximal to arculus
  • b ↑
  • Libellulidae: Key couplet 41 of 67

  • couplet drawing
  • ● Tip of anal loop usually open on one or both sides of midvein, the bounding veins of loop extending to wing margin, occasionally closed, the bounding veins meeting at wing margin
  • a ↑
  • Libellulidae: Key couplet 42 of 67

  • couplet drawing
  • ● Abdomen tapering progressively from segment 3 to tip
    ○ Variable, yellowish-brown patch between triangle and nodus of hindwing, sometimes very faint
    ○ Male abdomen orange-brown

    ⇒ species: Twister (Tholymis tillarga)
  • a ↑
1  
  • Libellulidae: Key couplet 1 of 67

  • couplet drawing
  • ● Distal antenodal of forewing complete, both costal and subcostal sections present
a ↑
b ↓
  • couplet drawing
  • ● Distal antenodal of forewing incomplete, only the costal section present

2  
  • Libellulidae: Key couplet 35 of 67

  • couplet drawing
  • ● Hindwing triangle crossed
a ↑
b ↓
  • couplet drawing
  • ● Hindwing triangle free

3  
  • Libellulidae: Key couplet 39 of 67

  • couplet drawingcouplet drawing
  • ○ Small (hindwing c. 25 mm)
    ● Synthorax and abdomen black with well-defined pale yellowish-green markings

    ⇒ species: Forestwatcher (Huonia melvillensis) (part)
a ↑
b ↓
  • ○ Not as above

4  
  • Libellulidae: Key couplet 40 of 67

  • couplet drawing
  • ● Base of hindwing triangle well beyond arculus

    ⇒ species: Spiny-Chested Percher (Raphismia bispina)
a ↑
b ↓
  • couplet drawing
  • ● Base of hindwing triangle at or slightly proximal to arculus

5  
  • Libellulidae: Key couplet 41 of 67

  • couplet drawing
  • ● Tip of anal loop usually open on one or both sides of midvein, the bounding veins of loop extending to wing margin, occasionally closed, the bounding veins meeting at wing margin
a ↑
b ↓
  • couplet drawing
  • ● Tip of anal loop closed, the bounding veins meeting midvein one row of cells away from wing margin

6  
  • Libellulidae: Key couplet 42 of 67

  • couplet drawing
  • ● Abdomen tapering progressively from segment 3 to tip
    ○ Variable, yellowish-brown patch between triangle and nodus of hindwing, sometimes very faint
    ○ Male abdomen orange-brown

    ⇒ species: Twister (Tholymis tillarga)
a ↑
b ↓
  • couplet drawing
  • ● Abdomen narrowing abruptly within the length of segment 3
    ○ Wing tips variably darkened, sometimes hyaline, rest of wing membrane hyaline except for dark flecks at extreme base and, in some, a dark costal band, or with general yellowish-brown suffusion
    ○ Male abdomen dull brown to blackish brown

    ⇒ genus: Zyxomma

Australian distribution