Ischnura  (Ischnura abyssinica)

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

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).

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

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 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).

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).

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