Elfin skimmer (Nannothemis bella)
|Size||Length: 1.8 - 2 cm (2) (3)|
Hind wing length: 1 - 1.5 cm (2) (3)
- The elfin skimmer is the smallest dragonfly in North America, and one of the smallest dragonflies in the world.
- The adult elfin skimmer reaches only around two centimetres in length.
- The black and yellow colouration of the female elfin skimmer is thought to mimic the appearance of wasps and bees.
- The elfin skimmer has quite specific habitat preferences, being found mainly in sphagnum bogs and fens.
The elfin skimmer has yet to be classified by the IUCN.
The elfin skimmer (Nannothemis bella) is a tiny, distinctively marked dragonfly (2) which has the distinction of being the smallest dragonfly species in North America (4) (5). This species is the only member of its genus (2), and varies in colouration with age as well as between the sexes (2) (3) (4) (5).
Immature male elfin skimmers are shiny black, but around five to ten days after emerging as adults they become a powdery blue-grey colour (2) (4) (6). The male’s eyes are blue-grey or silver with reddish-brown stripes around the rear edges, and the face is black with white around the top and sides (2) (4). The eyes barely meet on top of the head (3).
In contrast to the male, the female elfin skimmer is striped with black and yellow, giving it a wasp- or bee-like appearance (2) (4) (5) (6). Whereas the male elfin skimmer has transparent wings, the wings of the female often have an amber tinge towards the base (2) (3) (4) (6). Very young, newly emerged adult elfin skimmers are reported to be lime green in colour (2).
The elfin skimmer has a slender abdomen (3), which in the male widens into a flat club shape at the end (4) (5) (6). The legs of this species are black (3).
The elfin skimmer is widespread across most of the eastern United States and into parts of Canada (4) (7). However, this species has quite specialised habitat preferences, meaning that its populations are quite localised within this large range (2).
The elfin skimmer inhabits sphagnum bogs and sometimes calcareous fens in sedge meadows (2) (4) (5) (6) (8).
Relatively little information is currently available on the biology of this diminutive dragonfly. However, as in other dragonflies its aquatic larvae, known as nymphs, are likely to be opportunistic predators which take a variety of prey. In general, dragonfly nymphs ambush their prey, catching it by shooting out their fiercely hooked lower jaw, or ‘labium’, which impales the victim and drags it back to the mouth (9). The nymphs of the elfin skimmer are reported to occur in small pools and puddles in sphagnum, away from the water’s edge (8).
Like other dragonfly nymphs, the nymphs of the elfin skimmer go through a number of developmental stages, or ‘instars’, before emerging as an adult dragonfly (9). This species may spend as long as two years as a nymph before it emerges as an adult (3). Adult elfin skimmers are seen between May and September (2) and, like the nymphs, are opportunistic predators. All dragonflies have acute vision and excellent powers of flight, and typically hunt flying insects on the wing (9).
The elfin skimmer characteristically droops its wings while perching (2) (5). This species often perches in low shrubs and sedges around water (2), and usually forages low over bogs, flying in and out of the vegetation (5).
The male elfin skimmer holds a small territory at a breeding pool, defending it against rival males (2) (10). The female lays her eggs by tapping the water a few times with her abdomen, releasing the eggs into the water (2) (9), and she is often guarded by the male at this time (2) (5).
Relatively little is currently known about the potential threats to the elfin skimmer. Populations of this tiny dragonfly are generally thought to be stable, although the species is rare and potentially threatened in some parts of its range (7). Common threats to dragonfly species in general include pollution and the destruction of wetland habitats (9).
No specific conservation measures are currently known to be in place for the elfin skimmer.
Find out more about the elfin skimmer:
NatureServe Explorer - Nannothemis bella:
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The Xerces Society:
This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
- Abdomen: in arthropods (crustaceans, insects and arachnids) the abdomen is the hind region of the body, which is usually segmented to a degree (but not visibly in most spiders). In crustaceans (such as crabs), some of the limbs attach to the abdomen; in insects the limbs are attached to the thorax (the part of the body nearest to the head) and not the abdomen.
- Calcareous: containing calcium carbonate, chalky.
- Fen: wetland with alkaline, neutral or only slightly acidic peaty soil. The alkalinity arises due to ground water seeping through calcareous rocks (rocks containing calcium carbonate).
- Genus: a category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.
- Larvae: stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.
- Nymph: stage of insect development, similar in appearance to the adult but sexually immature and without wings. The adult form is reached via a series of moults and the wings develop externally as the nymph grows.
- Sphagnum: a moss of the genus Sphagnum, which typically grows in bogs and whose decomposed remains contribute to the formation of peat.
- Territory: an area occupied and defended by an animal, a pair of animals or a colony.
Integrated Taxonomic Information System (ITIS) (September, 2013)
- Paulson, D. (2011) Dragonflies and Damselflies of the East. Princeton University Press, Princeton, New Jersey.
- Needham, J.G. and Westfall, M.J. (1975) The Manual of the Dragonflies of North America (Anisoptera): Including the Greater Antilles and the Provinces of the Mexican Border. University of California Press, Berkeley and Los Angeles.
Wisconsin Odonata Survey - Nannothemis bella (September, 2013)
Pennsylvania Natural Heritage Program - Elfin skimmer (September, 2013)
- Dunkle, S.W. (2000) Dragonflies through Binoculars: A Field Guide to Dragonflies of North America. Oxford University Press, New York.
NatureServe Explorer - Nannothemis bella (September, 2013)
Odonata Larvae of Michigan - Notes on Nannothemis bella in Michigan (September, 2013)
- O'Toole, C. (2002) The New Encyclopedia of Insects and their Allies. Oxford University Press, Oxford.
- Hilder, B.E. and Colgan, P.W. (1985) Territorial behaviour of male Nannothemis bella (Uhler) (Anisoptera: Libellulidae). Canadian Journal of Zoology, 63(5): 1010-1016.