Thursday, August 12, 2021

[Entomology • 2021] Macromia weerakooni • A New Dragonfly Species (Odonata: Anisoptera: Macromiidae) from Sri Lanka

 Macromia weerakooni  Sumanapala, 2021

The genus Macromia is represented in Sri Lanka by two endemic species. In this paper a third presumed endemic species is described based on a single male specimen collected at Kirikitta, Weliweriya, Western Province in the low country wet zone of the country. Macromia weerakooni sp. nov. differs from its congeners in Sri Lanka by having turquoise blue eyes, an entirely black labrum, a short yellow ante-humeral stripe, an interrupted yellow stripe on the anterior margin of metepisternum anddifferences in the secondary genitalia and anal appendages. As this is the only record of the species knowledge of its natural history and distribution is limited. This discovery highlights the need for further systematic surveys of Odonata in Sri Lanka using sampling methods suitable for the detection of elusive species.

Keywords: new species; endemic; South Asia

Figure 1: Macromia weerakooni sp. nov. holotype in life. Dorsal view.

Genus Macromia Rambur, 1842 

Macromia weerakooni sp. nov.

Differential diagnosis: A large, black Macromia marked with yellow, with turquoise blue eyes and a turquoise blue sheen on metalic green thorax. It can be distinguished from the two other known species of Macromia in Sri Lanka by having (1) turquoise blue eyes in adults (vs. bottle green), (2) entirely black labrum (vs. labrum with yellow markings), (3) a short citron yellow triangular antehumeral stripe that reaches less than half of the length of mid-dorsal carina (vs. long antehumeral stripe in M. zeylanica and no antehumeral stripe in M. flinti), (4) an interrupted citron yellow stripe in the anterior margin of metepisternum (vs. continuous stripe in M. zeylanica and M. flinti), (5) an upward pointed, laterally flattened short spine with a broad base on the dorsal carina of last abdominal segment (vs. a broad based slightly lower and less pointed short spine in M. zeylanica and a thin, long, backward pointed spine in M. flinti), (6) cerci having a gently outward curved pointed apex (vs. an inward curved, blunt apex in M. zeylanica and an outward curved, thin, elongated and pointed apex in M. flinti), (7) Almost entirely black tergum between the roots of the wings except for a small yellow spot between forewings (vs. prominent yellow markings across tergum in both M. zeylanica and M. flinti) and (8) differently shaped secondary genitalia. Macromia weerakooni sp. nov. is clearly distinguishable from its congeners of the genus Macromia in the Western Ghats region, India other than Macromia flavicincta Selys, 1874; Macromia irata Fraser, 1924 and Macromia bellicosa Fraser, 1924 based on the structure of the secondary genitalia. It can be distinguished from the latter three species by (1) comparatively less tapering (vs. more tapering) apex of cerci, (2) shape of the dorsal spine on S10, (3) predominantly black face with some citron yellow markings (vs. predominatly citron yellow face with less black), (4) interrupted citron yellow stripe in in the anterior margin of metepisternum (vs. continuous stripe).

 Etymology: The specific epithet is a latinized genitive singular of Weerakoon, honouring Prof. Devaka K. Weerakoon (University of Colombo, Sri Lanka). He is an inspirational figure behind numerous biologists in the country and an academic spearheading the science based conservation activities in Sri Lanka. The author wishes to express his sincere gratitude to Prof. Weerakoon for all the guidance, support and encouragement generously provided throughout his career. 

A comparison between males of Macromia weerakooni sp. nov. (A) and Macromia zeylanica (B) in life.

Amila Prasanna Sumanapala. 2021. Macromia weerakooni sp. nov. (Odonata: Anisoptera: Macromiidae), A New Dragonfly Species from Sri Lanka. International Journal of Odonatology. 24; 169–177.