Long-Tailed Duskdarter (Zyxomma petiolatum)

The Long-Tailed Duskdarter (Zyxomma petiolatum) 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, 8 of which are pertinent to Zyxomma petiolatum. 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.

#	Family	Species	Couplet No.
	Libellulidae	Long-Tailed Duskdarter (Zyxomma petiolatum)	Libellulidae: Key couplet 1 of 67 ● Distal antenodal of forewing incomplete, only the costal section present b ↑ Libellulidae: Key couplet 35 of 67 ● Hindwing triangle free b ↑ Libellulidae: Key couplet 39 of 67 ○ Not as above b ↑ Libellulidae: Key couplet 40 of 67 ● Base of hindwing triangle at or slightly proximal to arculus b ↑ Libellulidae: Key couplet 41 of 67 ● 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 ● 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 b ↑ Libellulidae: Key couplet 43 of 67 ● Abdomen segment 4 not strongly constricted at supplementary transverse carina, posterior width of segment commonly less than anterior width b ↑ Libellulidae: Key couplet 44 of 67 ○ Abdomen several mm longer than hindwing ● Junction of abdominal segments 3 and 4 strongly bowed forwards ⇒ species: Long-Tailed Duskdarter (Zyxomma petiolatum) b ↑
1			Libellulidae: Key couplet 1 of 67 ● Distal antenodal of forewing complete, both costal and subcostal sections present a ↑ b ↓ ● Distal antenodal of forewing incomplete, only the costal section present
2			Libellulidae: Key couplet 35 of 67 ● Hindwing triangle crossed a ↑ b ↓ ● Hindwing triangle free
3			Libellulidae: Key couplet 39 of 67 ○ 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 ● Base of hindwing triangle well beyond arculus ⇒ species: Spiny-Chested Percher (Raphismia bispina) a ↑ b ↓ ● Base of hindwing triangle at or slightly proximal to arculus
5			Libellulidae: Key couplet 41 of 67 ● 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 ↓ ● 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 ● 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 ↓ ● 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
7			Libellulidae: Key couplet 43 of 67 ● Abdomen segment 4 strongly constricted at supplementary transverse carina, anterior and posterior widths of segment approximately equal ⇒ species: Large Duskdarter (Zyxomma multinervorum) a ↑ b ↓ ● Abdomen segment 4 not strongly constricted at supplementary transverse carina, posterior width of segment commonly less than anterior width
8			Libellulidae: Key couplet 44 of 67 ○ Abdomen not longer than hindwing ● Junction of abdominal segments 3 and 4 almost straight ⇒ species: Short-Tailed Duskdarter (Zyxomma elgneri) a ↑ b ↓ ○ Abdomen several mm longer than hindwing ● Junction of abdominal segments 3 and 4 strongly bowed forwards ⇒ species: Long-Tailed Duskdarter (Zyxomma petiolatum)