Lestes birmana Selys, 1891

Kosterin, Oleg E. & Poggi, Roberto, 2015, Taxonomical notes on Indolestes Fraser, 1922 (Lestidae, Zygoptera). 2. Indolestes birmanus (Selys, 1891) is bona species, IDF-Report 81, pp. 13-20 : 16-19

publication ID	https://doi.org/ 10.5281/zenodo.3369146
persistent identifier	https://treatment.plazi.org/id/0385E558-FB72-FF98-FD82-0D07FB76D4E0
treatment provided by	Jeremy
scientific name	Lestes birmana Selys, 1891
status

Treatment

Holotype of Lestes birmana Selys, 1891

The holotype of Lestes birmana ( Figure 2 View Figure 2 ) is present in good condition in Museo Civico di Storia Naturale 'Giacomo Doria' ( Figure 4a View Figure 4 ). It has a small handwritten yellow label “Puepoli / 18. VI. 88 ", a yellow label “ Lestes / birmana Selys / ( divisa ? Hagen) / Puepoli / ♂ written by Selys' hand, a red label “HOLOTYPUS / ♂ / Lestes / birmana / Selys, 1891 " and a pale gray printed label “Museo Civico di Genova" ( Figure 4b View Figure 4 ) GoogleMaps .

Of its diagnostic characters the following should be mentioned:

- a broad black humeral stripe with three slanting ledges at its lower margin ( Figure 3d View Figure 3 );

- S9 entirely black ( Figure 3e View Figure 3 ), except for two pairs of tiny light spots, lateral and lateroposterior, seen only in lateral view ( Figure 3f View Figure 3 ); S10 entirely light ( Figure 3e View Figure 3 );

- cerci in dorsal view long, with apices rather strait, moderately broadened and negligibly attenuated caudad and touching each other ( Figure 3a View Figure 3 ).

- a small and short apical tooth on each paraproct, seen in dorsoposterior view ( Figure 3b View Figure 3 ).

Discussion

Note that at present, the species to which this note is devoted is considered in the genus Indolestes Fraser, 1922 . This genus, as well as the genus Lestes Leach, 1815 , are now considered to be of the masculine gender, so the correct combination and spelling, according to the ICZN Art. 34.2, of the species is Indolestes birmanus ( Selys, 1891) . In the past, the mentioned genera, and also Ceylonolestes Kennedy, 1920 (presently a synonym of Austrolestes Tillyard, 1913 , see Bridges 1994), were considered in the feminine gender, hence Selys (1891) and Fraser (1930; 1933), but not Ris (1 916), used species epithets in these genera in the feminine gender. In Introduction, we mentioned the names in combinations and spellings as used by the cited authors. Below we will use the correct modern combinations and spellings.

The most important diagnostic character in Indolestes is the shape of cerci. The holotype of birmanus has their apices rather long, longer than in I. divisus ( Figure 1b View Figure 1 ) but scarcely attenuated caudad, thus differing from I. gracilis (se e Kosterin 2015, this issue). It may be said that their shape is intermediate between the two last mentioned taxa.

The diagnostic value of the short apical tooth on each paraproct is unclear. This trait was neither mentioned for I. gracilis or I. divisus nor shown in the drawing of I. birmanus ( Figure 1a View Figure 1 ) by Asahina (1970). The paraprocts of the related species Indolestes peregrinus ( Ris, 1916) are pointed but with attenuated tips ( Asahina 1976; see also Kosterin 2015: figs 2a-d).

The humeral black pattern can be variable in Sympecmatinae. It is, for instance, variable in I. gracilis gracilis in Ceylon ( Lieftinck 1940), from complete absence to 3-4 isolated spots or even fused into irregular fascia, as in the holotype of birmanus . However, the holotype of birmanus shows a peculiar colorational character: the black S9, while in such taxa as gracilis s. str., divisus and davenporti its apical part is always blue in males ( Fraser 1933; Bedjanic et al. 2014). The same entirely black S9 is found in the Himalayan species Indolestes cyaneus (Selys, 1862) , which also has a very slightly attenuated but much broader apices of the cerci, besides it has paired black dorsal spots on S2-6 and is larger ( Fraser 1933). The characters of “ Lestes (Indolestes) birmanus " depicted by Asahina (1970) ( Figure 1a View Figure 1 ) are the same as in the holotype, except for the cerci apices being not at all attenuated caudad. Their crossing is just a matter of an orientation of a movable organ.