Fiery Emperor (Anax immaculifrons)

 An uncommon dragonfly occurs mainly in the hill country streams with pools as well as the tanks and lakes. But it can be found in low country wet zone and intermediate zones too. Rather common from March to May and August to October. When ovipositing female of this dragonfly insert her eggs into under water plant materials, while male hovering or flying close to her, sometimes also fighting with other rival males. 

Red-veined Darter (Sympetrum fonscolombii)

 Rather rare insect confined to the marshes, swamps and lakes of the central hills (Mainly to the vicinity of Nuwaraeliya and Horton Plains National Park.) 

Triangle Skimmer (Orthetrum triangulare triangulare)

Rather rare dragonfly found in marshes, streams and pools of the higher elevations in the Knuckles range and Central hills. Isolated records also available from Nakiyadeniya, Hiyare and Kanneliya.

Black-tipped Percher (Diplacodes nebulosa)

Rather uncommon dragonfly usually found perch on grasses or sticks in wet lowland areas such as marshes, ponds, tanks and nearby vegetation, in all climatic zones.  It occurs all the year round though much common during May and June. As per Bedjanic M, et. al., 2014 the lack of recent records of this dragonfly in the north and east is probably due to less intensive field works in that part of the island, though there are some old records from those areas as well. This individual was photographed at Batticaloa of eastern province in a lawn close to the old Dutch fort on 8th August 2016 confirming its inhabitancy in the eastern part of the country. 

Sri Lankan Cascader (Zygonyx iris ceylonicus)

An endemic dragonfly rather common at mid elevations of the southwestern wet zone. Also occurs in the intermediate zone, but absent in the coastal areas and higher hills. Fast flowing water near waterfalls and cascades are the preferred habitats of this rather large size cascader. It can be seen gliding continuously over the water with swift turns in such habitats. 

Sapphire Fluterer (Rhyothemis triangularis)

Rather rare dragonfly found in marshes, ditches, tanks and slow moving rivers, mainly in the low country wet zone. But there are records also from drier parts of the island. 

Lyrate Grappletail (Heliogomphus lyratus)

In June 1926 G,M, Henry collected a single male and female of this very rare and probably seasonal dragonfly from the Haldummulla. F.C. Fraser later on described it as a new Gomphidae species endemic to the Sri Lanka base on those specimens. For over 80 years till in May 2009 Matjaz Bedjanic's records of single male in Kitulgala and a female in Morawaka-Diyadawa road on the slopes of Diyadawa forest, that was the sole available information of this species.
  We could observe and photograph a Male and female on early April of 2015 at a small well shaded stream of Kukulugala proposed forest reserve in the Ratnapura district. Female was oviposting in a small water hole of the stream during our observation and male when disturbed rapidly flew directly upward up to certain height.

* Another single male observed end of May 2015 while settled on a leaf along the roadside from Athweltota to Rusigala in Kaluthara district, a rather disturbed and open habitat comparing to the all of above locations.

References:

de Fonseka, T. (2000). The dragonflies of Sri Lanka. Wildlife Heritage Trust: Colombo. 304 p. 

Fraser F.C. 1933 The Gomphines of Ceylon (Order Odonata), F.C. Fraser, Ceylon Journal of Science (B) Vol. XVIII, Pt 1 December 22, 1933 page 33 

Bedjanic, M., K. Conniff, N. van der Poorten & A. Salamun, 2014. Dragonfly fauna of Sri Lanka: Distribution and biology, with threat status of its endemics. Pensoft, Sofia. 321pp.

Rivulet Tiger (Gomphidia pearsoni)

Rivulet Tiger is the biggest of all endemic Clubtails. It occurs in streams, rivulets and rivers in the primary and secondary rain forests and adjacent less disturbed habitats in the central and southwestern part of the island. Distribution records also available from outskirt of Knuckles range and Diyaluma fall area of southeastern mid-hills. 

Dingy Duskflyer (Zyxomma petiolatum)

An uncommon dragonfly inhabiting ponds, lakes, rivers, tanks and lagoons of lowland areas. It is a crepuscular dragonfly and active only during the dusk, while rest in thick scrub jungles during the day. Dingy Duskflyer is a fast flyer and feeds mainly on mosquitoes looping around over still water. 

Burmeister's Glider/Keyhole Glider/Saddlebags Glider (Tramea basilaris burmeisteri)

Rather rare high-flying dragonfly occurs in weedy tanks and ponds in the dry lowlands. 

Sombre Lieutenant (Brachydiplax sobrina)

Rather common dragonfly inhabiting weedy ponds, tanks, channels, lagoons and marshes mainly in the lowlands throughout the year. 

Sri Lanka Cruiser (Macromia zeylanica)

Rather rare endemic dragonfly inhabiting streams and rivulets in the forests of southwestern lowlands up to mid hills. It is a fast-flying insect which flies low over pebbles of a stream or rivulet.

Sri Lanka Forktail (Macrogomphus lankanensis)

Rather uncommon dragonfly occurs in rivers and stream habitats from lowlands to mid hills. 

Blue Pursuer (Potamarcha congener)

Blue Pursuer is a locally common dragonfly found in small weedy ponds and marshes from lowlands to mid-hills. 

Wandering Glider (Pantala flavescens)

Very common insect inhabiting marshes, paddy fields, tanks etc. from lowlands to mid-hills. It usually emerges as large numbers when they do. Unlike most other dragonflies migratory habit has been observed among Wandering Gliders and high flying groups of them often seen away from water. 

Blue Percher (Diplacodes trivialis)

A very common dragonfly of the lowlands up to mid hills. It inhabits rice fields, weedy tanks, streams beaches and footpaths, often far from the water unlike most other dragonflies. 

Paddyfield Parasol (Neurothemis intermedia intermedia)

An uncommon dragonfly found in lowland forested areas, paddy fields, plantations and vicinity of tanks in the dry zone (bedjanic, M., K. Conniff & G. de Silva Wijeyeratne, 2007). Rare in the hills. 

Wall’s Grappletail (Heliogomphus walli)

Wall’s Grappletail is a rare endemic dragonfly inhabiting fast flowing forested streams. Earlier records only exist from Morningside estate of Rakvana, Balangoda and Nalanda (de Fonseka T., 2000). 

Brook Hooktail (Paragomphus henryi)

Locally common dragonfly inhabiting fast flowing streams and rivers in submontane areas according to the de Fonseka (de Fonseka T., 2000) and hills and mountain regions as per bedjanic, M.,  et.al., 2007. However F.C. Fraser in 1933 noted that it is the commonest Gomphine in the island found in everywhere at all elevations (Fraser F.C. 1933). Probably what he meant is in suitable habitats as he elaborated further that it is a jungle insect usually found sunning itself on rocks in mid streams. With the recent distribution data of Brook Hooktail in the island M. Bedjanic concluded that P. henryi is not so common anymore, being known from around 70 localities concentrated in central and southwestern part of Sri Lanka (Bedjanic M., 2013) Above picture was taken at lowland rain forest stream of southwestern Sri Lanka (Indikada Mookalana – A heavily degraded secondary forest) with about 40m height above sea level (6°54.072'N, 80°09.724'E). Males Brook Hooktail can be easily distinguished from all others of the family by having long hook like down-curved anal appendages (insert). Female lack that expansion.

Fraser F.C. 1933 The Gomphines of Ceylon (Order Odnata), F.C. Fraser, Ceylon Journal of Science (B) Vol. XVIII, Pt 1 December 22, 1933 page 33 

bedjanic, M.,  K. Conniff & G. |de Silva Wijeyeratne, 2007, Gehan's photo guide: Dragonflies of Sri Lanka. Jetwing Eco Holidays, Colombo 248p.

de Fonseka, T. (2000). The dragonflies of Sri Lanka. Wildlife Heritage Trust: Colombo. 304 p. 

bedjanic, M. 2013 Paragomphus Campestris Spec.Nov., A New endemic dragonfly from Sri Lanka (Ansoptera:Gomphidae) Odonatologica 42(1): 45-53 March 1, 2013 (http://www.rufford.org/files/Odonatologica%2042(1)%2045-53%20March%201,%202013.pdf)

Amber-winged Glider (Hydrobasileus croceus)

A very rare dragonfly recorded only once in Sri Lanka from the Kandy according to the Terrence de Fonseka (de Fonseka T., 2000). However 2012 National red list listed it under Near Threatened category probably due to records of more occurrences of it in the island than previously thought. Both sexes are similar and it can be easily identified by the amber color patch on the hind-wing. It is said that it breeds on weedy tanks and where males can be found waiting for females( de Fonseka T., 2000 quoting Fraser ). I have encountered two specimens on 16th February 2013 close to the Kalu River at Dombagaskandha forest reserve in Ingiriya. First one was flying about 2-3 m above the ground (Time - Around 1PM) close to a tributary of Kalu River. Second one was resting on a road side shrub during the evening (Time - Around 4 PM).