Lestidae, Calvert, 1901

J. A. L. Watson & M. S. Moulds, 1979, New Species of Australian Lestidae (Odonata), Australian Journal of Entomology 18, pp. 143-155 : 143-144

Key to species of Australian Lestidae

1. Quadrilateral cells of fore and hind wing similar in size and shape, that of hind wing less than 1.10 times length of fore wing quadrilateral ............................................. Lestes concinnus (Burmeister)

Quadrilateral cell of hind wing more than 1.15 times, usually 1.3-1.5 times, longer than that of fore wing ...... .. 2

2. Front of synthorax marked with vertical metallic green stripe on each side, expanded laterally near centre to form brownish or green spot; Ac approximately midway between Ax1 and Ax2 in fore wing, often nearer to Ax2 ............................................. Indolestes Fraser 3

Front of synthorax unicolorous or striped, the stripe not expanded at centre; Ac generally near Ax1, basal or distal, occasionally almost midway between Ax, and Ax2 ... Austrolestes Tillyard 5

3. Hind wing of male less than 20 mm long, of female less than 21 m m ............................................................................. I. alleni (Tillyard)

Hind wing of male 20 mm or more long, of female 21 mm or more .. 4

4. Abdominal tergites 3-6 marked with pale basal ring, blue in mature male, ill-defined in mature female; metapleural suture marked brown only at upper end; superior appendages of male sinuate, reflexed and broadly contiguous at tips .. .. I. tenuissimus (Tillyard)

Abdominal tergites 3-6 with pale basal ring and subapical band, whitish in mature specimens; metapleural suture narrowly marked dark brown; superior appendages convergent at tips, forcipate........................................................................................ I. obiri sp. n .

5. Pterostigma overlying crossveins of adjoining row only near each end; Ac far beyond level of Ax1, generally about midway between Ax, and Ax2; metapleural suture not marked with pigmented stripe; abdominal tergite 2 marked with dark longitudinal stripe on each side of pale midline, or with ill-defined marks on pale background ................................................................. A. insularis Tillyard

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; metapleural suture variable; abdominal tergite 2 with well-defined light and dark pattern, or substantially dark .. 6

6. Pale humeral stripe broad, its upper end crossing mesopleural suture onto mesepimeron and subalar ridge almost to segmental ju n c tio n ................................................................................................... 7

Pale humeral stripe narrow, with at most a small upper patch extending across mesopleural suture, not meeting subalar ridge .. 8

7. Metapleural suture narrowly lined black from subalar ridge to spiracle; abdominal segments 9-10 of male pale above .. .. ...................................................................................... A. aridus (Tillyard)

Upper quarter to third of upper metapleural suture marked black; abdominal segment 10 of male pale above. .. A. analis (Rambur)

8. Humeral stripe extending across mesopleural suture .................................. 9

Humeral stripe not extending across mesopleural s u t u r e ....................... 11

9. Abdominal segment 10 of male black; basal pale ring of abdominal tergite 7 of female broad, occupying approximately 20% of length of segment ........................................................ A. minjerriba sp. n.

Abdominal segment 10 of male pale above; basal pale ring of abdominal tergite 7 of female narrow, occupying approximately 10% of length of s e g m e n t ................................................................... 10

10. Median lobe of pronotum with pale lateral margin; abdominal tergite 2 of male dark above, with pale, narrow middorsal line over distal t h i r d .................................................................. A. io (Selys)

Median lobe of pronotum dark laterally; abdominal tergite 2 of male marked with dark longitudinal stripe on each side of broad, pale m id lin e ............................................................................. A. leda (Selys)

11. Abdominal tergite 2 dark distally, with basal pale semicircular, triangular or pointed half-oval spot; superior appendages of- male sinuate, reflexed and broadly contiguous at tips .. .. ........................................................................... A. cingulatus (Burmeister)

Abdominal tergite 2 without pale basal spot; superior appendages of male forcipate, converging at t i p s ........................................................ 12

12. Ac proximal to Ax, in fore wing; abdominal tergites 3-7 of male substantially pale, with forward-pointing, dark arrow-shaped mark on posterior h a lf .................................................... A. annulosus (Selys)

Ac distal to Ax1 in fore wing; abdominal tergites 3-7 of male substantially dark, with pale basal r in g s ............................................. 13

13. Pale ring at base of abdominal tergite 7 occupying approximately 20% of length of se g m e n t...................................................... A. minjerriba sp. n.

Pale ring at base of abdominal tergite 7 occupying approximately 10% of length of segment, or l e s s ........................................................ 14

14. South-eastern Australian; abdominal tergite 2 of male with dorsal dark mark, slightly constricted at centre .. A. psyche (Hagen in Selys)

South-western Australian; dorsal mark on abdominal tergite 2 of male strongly constricted at centre, forming narrow stem .. ........................................................................................ A. aleison sp. n .