Ischnura (Ischnura abyssinica)

Description

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Ischnura fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Ischnura description

Ischnura abyssinica is a damselfly in the family Coenagrionidae, more commonly known as the ‘fork tails’, due to the distinctive forked shaping of their tail ⁽²⁾. Virtually no information is available on Ischnura abyssinica; however, species in the Ischnura genus typically have a black abdomen, except for the eighth segment, which is always blue in the male, but can be brown, green, yellow or blue in the female ⁽³⁾.

Ischnura species also have a short ‘pterostigma’ (a thickened cell on the front edge of the wing), which is usually square in shape. These small cells are black in front and either blue or white behind on the male. The abdomen usually has a marked lump on the underside of the tenth segment. The female ovipositor has small but fairly visible spine ⁽³⁾.

Ischnura biology

Little information is available on the biology of Ischnura abyssinica, but there is currently an ongoing study to identify and record more information on this and many other species of African invertebrates ⁽⁴⁾.

Like most damselflies, Ischnura abyssinica is likely to have a fluttering weak flight pattern and be found at freshwater sites, sometimes massing in numbers exceeding hundreds of individuals. The male damselfly will typically remain close to the water source and is often stationary amongst the vegetation at the water edge. The female may be found in remote areas such as meadows, away from water sources ⁽²⁾.

In most damselfly species, the adult male will patrol a territory along the water edge, and will secure a mating with many different females. The male will often guard the female from competing males while the eggs are being laid. The female lays eggs inside vegetation underneath the water. Once hatched, the larvae feed on a variety of food types, from small organic matter to larger invertebrates. In most damselfly species, the development of the larvae is completed within one to two years ⁽²⁾. The larvae development can be very rapid, as they develop in stagnant water ^{(2) (3)}.

Adult damselflies are ferocious aerial predators, usually feeding on mosquitoes and midges ⁽²⁾.

Ischnura range

Endemic to Ethiopia, Ischnura abyssinica is recorded from two locations: Lake Alemaya in the north-east of Ethiopia and Addis Alem in central Ethiopia ⁽¹⁾.

Ischnura habitat

Ischnura abyssinica is found on grassy lake shores and stream pools in highland meadows ⁽¹⁾.

Ischnura status

Ischnura abyssinica is classified as Vulnerable (VU) on the IUCN Red List ⁽¹⁾.

Ischnura threats

Ischnura abyssinica is threatened by water pollution and the degradation of lakes, rivers and streams ⁽¹⁾. With increased human activities, such as mining and farming, the quality of many water sources required by Ischnura abyssinica is increasingly becoming degraded and uninhabitable ⁽⁵⁾. The depletion of suitable habitat is predicted to continue further as a result of fast human population growth in the Ethiopian highlands ⁽¹⁾.

Ischnura conservation

Assessments of the ecology, population numbers and distribution of Ischnura abyssinica are needed not only to aid in developing conservation measures, but also for solving taxonomic problems ⁽⁶⁾. Ischnura abyssinica, like many species of damselfly, is threatened by polluted water sources and so conservation of freshwater habitats and proper water management is needed ⁽¹⁾.

Find out more

To find out more about the conservation of dragonflies and damselflies see:

• Moore, N.W. (Ed.) (1997) Dragonflies - Status Survey and Conservation Action Plan. IUCN/SSC Odonata Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. Available at:
  http://data.iucn.org/dbtw-wpd/edocs/1997-042.pdf

Authentication

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:
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This species information was authored as part of the ARKive and Universities Scheme.

Glossary

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 crustacea (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.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

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.

Invertebrates

Animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.

Larva

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.

Ovipositor

The egg-laying organ of a female insect, consisting of a tube-like structure at the end of the abdomen. In worker bees and non-reproductive female wasps, it is modified into a sting.

Taxonomic

Relating to taxonomy, the science of classifying organisms, grouping together animals which share common features and are thought to have a common ancestor.

Territory

An area occupied and defended by an animal, a pair of animals or a group.

References

1. IUCN Red List (January, 2010)
   http://www.iucnredlist.org/
2. Corbet, P. and Brooks, S. (2008) Dragonflies. HarperCollins Publishers, London.
3. D'Aguilar, J., Dommanget, JL. and Prechac, R. (1986)  A field guide to the Dragonflies of Britain, Europe and North Africa. William Collins Sons & Co Ltd, London.
4. Dijkstra, K.-D.B. (2007) The name-bearing types of Odonata held in the Natural History Museum of Zimbabwe, with systematic notes on Afrotropical taxa. Part 2: Zygoptera and species descriptions. International Journal of Odonatology, 10(1): 1-29.
5. Clausnitzer, V. and K.-D.B. Dijkstra (2005) The dragonflies (Odonata) of Ethiopia, with notes on the status of endemic taxa and the description of a new species. Entomologische Zeitschrift, 115: 117-130.
6. Clausnitzer, V. and Jödicke, R. (2004) Guardians of the watershed. Global status of dragonflies: critical species, threat and conservation. International Journal of Odonatology, 7: 111-430.