Lestes, Leach, 1815

Kosterin, Oleg E., 2019, Amendments and updates to F. C. Fraser’s key to Indian Lestes spp. (Odonata Lestidae) to resolve confusion of L. patricia Fraser, 1924 and L. nigriceps Fraser 1924, with notes on L. nodalis Selys 1891 and L. garoensis Lahiri, 1987, Zootaxa 4671 (2), pp. 297-300 : 299-300

For a reader’s convenience, the amended Fraser’s key to males of the species of Lestes , Platylestes Selys, 1862 and Sinhalestes Fraser, 1951 of India, Pakistan, Sri Lanka, Bangladesh and Myanmar is reproduced below entirely (in spite of the lack or scarce new information on some species). The genus Sinhalestes was introduced by Fraser (1951) for Lestes orientalis Hagen in Selys, 1862 after publication of his monograph ( Fraser 1933). Lestes bilineatus Selys, 1891 and Lestes malaisei Schmidt, 1964 , described from Myanmar, are not included as most probably belonging to Indolestes Fraser, 1922 (see, respectively, Lieftinck (1960) and Kosterin (2018)). Both L. nodalis (occurring at least in Lower Myanmar) and L. garoensis are included. The volume and limits of the genus Platylestes are unclear and the attribution of the praemorsus - group to either Lestes or Platylestes is equivocal ( Kosterin 2018); here they are referred to in Lestes just in accordance with the current practice. Also I abstain from inclusion of subspecies of Lestes praemorsus Hagen in Selys, 1862 since this matter is insufficiently resolved. The measurement ranges for Lestes dorothea Fraser, 1923 are given as extended by Lahiri (1987). Fraser’s “thorax” is replaced by a more correct “synthorax”. Fraser’s statement “Thorax immaculate” for Lestes nodalis Selys, 1891 contradicts his own description of this species ( Fraser 1933) and corrected to “Synthorax with few black spots”.

1. Synthorax without metallic markings ...................................................................... 2

Synthorax with green metallic antehumeral stripes........................................................... 6

2. Pterostigma unicolorous................................................................................ 3

Pterostigma bicolorous................................................................................ 4

3. No broad black dorsal stripe on synthorax (middorsal carina can be finely stressed with black); occiput reddish brown to creamy white; paraprocts extend at most to 1/3 of expanded part of cerci................................. L. concinnus Hag.

Synthorax with a broad black dorsal stripe; occiput mat black; paraprocts extend to the end of expanded part of cerci.............................................................................................. L. patricia Fras.

4. Synthorax with about 10 small black spots on each side; pterostigma white at both ends.............. P. platystylus Ramb.

Synthorax (in mature individuals) with few black spots; pterostigma with its costal third palest brown, posterior two thirds dark brown.............................................................................................. 5

5. Apices of cerci rounded, of their inner margins blunt............................................. L. nodalis Selys

Apices of cerci and their inner inflations strongly pointed....................................... L. garoensis Lahiri

6. Synthorax with a uniform narrow antehumeral stripe on each side.............................................. 7

Synthorax with narrow antehumeral stripes expanded outwardly at the upper side.................................. 9

Synthorax with antehumeral stripes deeply scalloped or crenulate on the outer sides............................... 10

Synthorax with the whole of dorsum and forepart of sides briliant metallic green................................. 10

7. Vertex of head metallic green; thorax largely black; only 11 postnodal nervures to fore-wings............ L. angularis Fras.

Vertex of head non-metallic; 12 to 14 postnodal nervures fore-wings............................................ 8

8. Vertex of head pale brown; dorsum of thorax pale brown, with very prominent brilliant metallic green antehumeral stripes; 12 postnodal nervures to fore-wings........................................................... L. viridulus Ramb.

Vertex of head mat black; dorsum of thorax black with an obscure narrow metallic green stripe on each side; 14 postnodal nervures to fore-wings.................................................................... L. nigriceps Fras.

9. Sides of thorax pale brown with a few black points................................................ L. elatus Hag.

Sides of thorax with two thick black bands enclosing a medial narrow brown stripe............... L. malabaricus Fraser

10. Small species, with abdomen 30-32 mm and hind-wing 20-21 mm .............................. L. praemorsus Selys

Larger species, with abdomen 36-41 mm and hind-wing 24-32 mm ................................. L.dorothea Fras.

11. Small species, with abdomen about 30 mm and hind-wing 21 mm; pterostigma bicolorous; palaearctic.... L. barbarus Fabr.

Large species, with abdomen 52 mm and hind-wing 38 mm; pterostigma unicolorous, oriental........... S. orientalis Hag.

Naturally, using any key is insufficient to identify tropical Odonata and the full descriptions should be consulted.

I should make a clarification on another matter concerned in Kosterin (2018). Matti Hämäläinen kindly informed me that the number of 366 species described by C.H. Fraser, which I cited in Kosterin (2018) according to Wasscher & Dumont (2013), was strongly underestimated. Kimmins (1966) mentioned 562 species group names described by him and although some of them proposed in a subspecific rank, the number of those described as species (not necessarily considered as valid species at present) was surely more than five hundred.

This work was partly supported by Russian State Scientific Project 0324-2019-0041. The author is grateful to K.D.P. Wilson and K.A. Subramanian for reviewing and improving the paper.