Blue-eyed Golden-ringed Dragonfly
Cordulegaster insignis Schneider, 1845
Order Dragonflies (Odonata)
Family Spike-tailed dragonflies (Cordulegastridae)
Conservation status: in Bulgaria: Critically endangered CR [B2a].
General distribution. Turkey, the Caucasian countries, Syria, Lebanon, Iraq, Iran, Afghanistan, Tajikistan and Kyrgyzstan. On the Balkan Peninsula it is found in Strandzha Mts., along the Black Sea coast and the Danube shore.
Distribution and abundance in Bulgaria. It was reported in the past with few specimens (nymphs and adults) from four localities [1, 2, 3] and found in another five in the recent years near the Danube and along the Black Sea coast. In four of them it has been proved as a reproducing one: along the Danube shore (the Barzartsi River near Archar Village and streams at the bank of the Danube near the villages of Dunavets and Vetren, Silistra District) and along the Black Sea coast (a stream in the Botanical Garden near Varna).
Habitats. The lower courses of small streams (with a width of about 0.5-1.5 m; a depth of 0.1-0.5 m) with banks densely overgrown with tree and shrub vegetation.
Biology. A representative of pelorheophilic cenosis [4]. The nymphs develop in the streams or in flooded areas in the surrounding regions (at a minimum depth of 0.01 m). Exuviae have been found exclusively on the stems and leaves of herbaceous plants in or around the water body. The adults perch on green stems of plants over the water surface. While looking for food they also fly over meadows close to tree and shrub vegetation distanced up to 100 m from the places of the development of nymphs.
Similar species. Cordulegaster bidentata, C. picta and C. heros, from which it differs by the blue eyes in mature specimens and the shape of the anal appendages. It differs from C. bidentata also with the lager yellow spots on the body, and from C. picta and C. heros also with the place of the spot on the first abdominal segment.
Negative factors. Human presence in the reproduction places: felling the shore vegetation (the stream near the village of Vetren), pollution with domestic waste (the Botanical Garden near Varna). The fluctuations of the waters of the Danube that raise the level of the lower courses of the inflowing streams.
Conservation measures taken. None
Conservation measures needed. Monitoring of the known populations along the Bulgarian section of the Danube and in the southeastern part of the country. Studying the ecology of the species. Informing the local population about the significance of Cordulegaster insignis as a species with a restricted distribution and as a destroyer of mosquitoes and other insects.
References. 1. Nedelkov, 1923; 2. Beschovski, 1964; 3. Beschovski, 1993; 4. Beschovski, 1967.
Author: Alexi Popov
