1st European Congress on Odonatology Programme and abstracts

Notes to the ecological demands of Cordulegaster heros
(Cordulegastridae) in its northern part of area in Slovakia
Otakar Holuša
Mendel University in Brno, Faculty of Forestry and Wood Technology,
Dept. of Forest Protection and Game Management,
Zemědělská 3, 613 00 Brno, Czech Republic
Cordulegaster heros Theischinger 1979 is Eastmediterranean species occurring in disjunctive
area within the Balkan Peninsula in Europe. Its habitat are smaller meandering streams, mostly
overshaded by tree vegetation in hilly landscape. Northern area border is still unclear – a larger
unbroken area is known from eastern Austria, Slovenia and south-western Hungary. An isolated area
is at present known from western Slovakia as a northernmost occurrence.
The occurrence of Cordulegaster heros was studied in detail in the southern part of Slovakia
during 1997-2009. The running waters of streamlets and streams (totally at 85localities) were
investigated in detail in regions of potential occurrence, i.e. southern Slovakia – regions of the Borská
nížina lowland, the Malé Karpaty Mts., the Cerové vrchovina hills, the Slánské vrchy Hills, the
Slovenský kras Hills, the Vihorlat Mts. and Popričný Hills. Data concerning morphology of stream
basin, pedological composition of sediments, water quality, state of vegetation and landscape etc.
were collected.
At present three regions with its occurrence are known – the Borská nížina lowland, the Malé
Karpaty Mts. in western Slovakia and the Revúcka vrchovina Hills in central Slovakia. The species was
totally found at 44 localities, which lay at the altitude from 194 to 516 m a.s.l. with its main
occurrence in the range of 200-300 m a.s.l. The evaluation of occurrence was based on records of
larvae. Its habitats are there natural streams and streamlets with clear water with the width of basin
from 20 to 420 cm with the depth of 2 to 18 cm. All localities lie in the forest complexes. The
important factor appears to be the absence of any settlement above the localities. The highest found
density of larvae (majority last larval instar - 14) was 25 per 0,25 m2. The occurrence of species ends
in the Malé Karpaty Mts. northwards, where the parent rocks of Mts. changes from crystalline into the
limestone. Area of C. heros in southern Slovakia is seemingly disjunctive.
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