Western Ringtail (Austrolestes aleison)

The Western Ringtail (Austrolestes aleison) is a damselfly species of the family Lestidae, which contains 14 species in Australia.

The identification key to the family Lestidae consists of 15 couplets, 10 of which are pertinent to Austrolestes aleison. 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.
	Lestidae	Western Ringtail (Austrolestes aleison)	Lestidae: Key couplet 1 of 15 ● Quadrilateral cell of hindwing more than 1.15 times, usually 1.3-1.5 times longer than that of forewing b ↑ Lestidae: Key couplet 2 of 15 ● Front of synthorax unicolorous or striped, the stripe not expanded near centre ● Ac generally near Ax1, basal or distal, occasionally almost midway between Ax1 and Ax2 ⇒ genus: Austrolestes b ↑ Lestidae: Key couplet 5 of 15 ● Central part of pterostigma overlying one or more crossveins of adjoining row ● Ac closer to level of Ax1 than of Ax2, sometimes basal to Ax1 ○ Abdominal tergum 2 with well-defined light and dark pattern, sometimes like that of dark A. insularis (see above), or substantially dark b ↑ Lestidae: Key couplet 6 of 15 ● Pale humeral stripe narrow, with at most a small upper patch extending across mesopleural suture, not meeting subalar ridge b ↑ Lestidae: Key couplet 8 of 15 ● Humeral stripe not extending across mesopleural suture b ↑ Lestidae: Key couplet 11 of 15 ○ Abdominal tergum 2 without pale basal spot ● Superior appendages of male forcipate, converging at tips b ↑ Lestidae: Key couplet 12 of 15 ○ Abdominal tergum 2 without pale mid-dorsal stripe b ↑ Lestidae: Key couplet 13 of 15 ● Ac distal to Ax1 in forewing ● Abdominal terga 3-7 of male substantially dark, with pale basal rings b ↑ Lestidae: Key couplet 14 of 15 ● Pale ring at base of abdominal tergum 7 occupying approximately 10% of length of segment, or less b ↑ Lestidae: Key couplet 15 of 15 ○ From south-western Australia ● Dorsal mark on abdominal tergum 2 of male strongly constricted at centre, forming narrow stem ⇒ species: Western Ringtail (Austrolestes aleison) b ↑
1			Lestidae: Key couplet 1 of 15 ● Quadrilateral cells of forewing and hindwing similar in size and shape, that of hindwing less than 1.10 times length of forewing quadrilateral ⇒ species: Dusky Spreadwing (Lestes concinnus) a ↑ b ↓ ● Quadrilateral cell of hindwing more than 1.15 times, usually 1.3-1.5 times longer than that of forewing
2			Lestidae: Key couplet 2 of 15 ● Front of synthorax marked with vertical, metallic green stripe on each side, expanded laterally near centre to form brownish green or green spot ● Ac approximately midway between Ax1 and Ax2 in forewing, often nearer to Ax2 ⇒ genus: Indolestes a ↑ b ↓ ● Front of synthorax unicolorous or striped, the stripe not expanded near centre ● Ac generally near Ax1, basal or distal, occasionally almost midway between Ax1 and Ax2 ⇒ genus: Austrolestes
3			Lestidae: Key couplet 5 of 15 ● Pterostigma overlying crossveins of adjoining row only near each end ● Ac far beyond level of Ax1, generally about midway between Ax1 and Ax2 ● Abdominal tergum 2 marked with dark longitudinal stripe on each side of pale midline, or with ill-defined marks on pale background ⇒ species: Northern Ringtail (Austrolestes insularis) a ↑ b ↓ ● Central part of pterostigma overlying one or more crossveins of adjoining row ● Ac closer to level of Ax1 than of Ax2, sometimes basal to Ax1 ○ Abdominal tergum 2 with well-defined light and dark pattern, sometimes like that of dark A. insularis (see above), or substantially dark
4			Lestidae: Key couplet 6 of 15 ● Pale humeral stripe broad, its upper end crossing mesopleural suture on to mesepimeron and subalar ridge almost to segmental junction a ↑ b ↓ ● Pale humeral stripe narrow, with at most a small upper patch extending across mesopleural suture, not meeting subalar ridge
5			Lestidae: Key couplet 8 of 15 ● Humeral stripe extending across mesopleural suture a ↑ b ↓ ● Humeral stripe not extending across mesopleural suture
6			Lestidae: Key couplet 11 of 15 ● Abdominal tergum 2 dark distally, with basal pale semicircular, triangular or pointed half-oval spot ● Superior appendages of male sinuate, reflexed and broadly contiguous at tips ⇒ species: Metallic Ringtail (Austrolestes cingulatus) a ↑ b ↓ ○ Abdominal tergum 2 without pale basal spot ● Superior appendages of male forcipate, converging at tips
7			Lestidae: Key couplet 12 of 15 ● Abdominal tergum 2 with pale mid-dorsal stripe over entire length, broad in male, narrow in female ⇒ species: Wandering Ringtail (Austrolestes leda) (part) a ↑ b ↓ ○ Abdominal tergum 2 without pale mid-dorsal stripe
8			Lestidae: Key couplet 13 of 15 ● Ac proximal to Ax1 in forewing ● Abdominal terga 3-7 of male substantially pale, with forward pointing, dark arrow-shaped mark on posterior half ⇒ species: Blue Ringtail (Austrolestes annulosus) a ↑ b ↓ ● Ac distal to Ax1 in forewing ● Abdominal terga 3-7 of male substantially dark, with pale basal rings
9			Lestidae: Key couplet 14 of 15 ● Pale ring at base of abdominal tergum 7 occupying approximately 20% of posterior half ⇒ species: Dune Ringtail (Austrolestes minjerriba) (part) a ↑ b ↓ ● Pale ring at base of abdominal tergum 7 occupying approximately 10% of length of segment, or less
10			Lestidae: Key couplet 15 of 15 ○ From south-eastern Australia ● Abdominal tergum 2 of male with dorsal dark mark, slightly constricted at centre ⇒ species: Cup Ringtail (Austrolestes psyche) a ↑ b ↓ ○ From south-western Australia ● Dorsal mark on abdominal tergum 2 of male strongly constricted at centre, forming narrow stem ⇒ species: Western Ringtail (Austrolestes aleison)