Odonata - Entomological Society of Latvia - Latvijas Daba

anks of the water bodies. Data on the physically-chemical parameters of the water bodies obtained
from http://www.ezeri.lv (2011), selecting the measurements closest to the date to the observation.
Aeshna subarctica. In order to identify the species the habitats (raised bogs with pools of
water and lakes; lakes with fens and poor fens) and micro habitats potentially suitable for the
species (imagos) were searched for the individual adults and exuviae. The habitats populated by the
species were described by the vegetation, the area and the location of the micro habitats in the
general habitat. The observed adult individuals and exuviae were counted. The exuviae were
searched by inspecting the vegetation 1-2m along the waterline or in all sample area. An egg laying
micro habitat and substrate was registered by observing egg-laying females. The inventories were
carried out on the banks of the water bodies.
In the sample areas established in the Large Kemeri Moorland in 2007 for the research of
dragonfly communities (see Chapter 2.2) the data on the number of exuviae in various bog habitats
were obtained. During the inventory, all identified exuviae in the sample area were collected.
Individual quantitative inventories were carried out in 2005 near the Grabatiņa Lake (31.07) and the
Meistara Lake (03.08.). The full coastline of both lakes was surveyed (300 m and 550 m,
accordingly) and all observed adult individuals were registered.
Ophiogomphus cecilia. In order to identify the species the habitats (rivers) and micro habitats
potentially suitable for the species were searched for adult individuals and exuviae. The habitats
populated by the species were described by the vegetation, width of the river, waterbed substrate
and adjacent habitats. The observed adult individuals and exuviae were counted. The inventories
were carried out on the banks of the water bodies and while in a boat. The inventories on a boat
were carried out in the following river segments:
• 07.-08.2001. the Ogre River: Ērgļi-Ogre segment (130 km) – only partly surveyed in a boat;
• 25.-27.07.2003. the Venta River: Alši-Kuldīga segment (75 km);
• 29.-30.07.2003. the Gauja River: Cēsis-Sigulda segment (45 km);
• 23.-24.06.2006. the Gauja River: the Taurene lake-Jēci segment (25 km);
• 30.-31.07.2004. the Gauja River: Aņņi-Strenči segment (55 km);
• 14.-15.08.2004. the Gauja River: Sikšņi-Tilikas segment (60 km);
• 23.-24.06.2007. the Gauja River: Dūre-Vireši segment (30 km);
• 22.06.2008. the Svētupe River: Pāle-Lauvas segment (10 km);
• 09.08.2008. the Svētupe River-Jaunupe: Lauvas-Salaca segment (20 km);
• 22.-23.06.2009. the Salaca River: Staicele-Vecsalaca segment (35 km);
• 24.-25.07. 2010. the Gauja River: Vidaga-Tilikas segment (55 km).
Within the segments surveyed in a boat, the adult individuals were counted and the maximal
and the mean number of individuals per kilometre were calculated. Also, the data from the 1998
research were used (see Chapter 2.3).
Leucorrhinia albifrons, L. caudalis and L. pectoralis. In order to identify the species the
habitats (stale water bodies) and micro habitats potentially suitable for the species were searched for
adult individuals and exuviae. The habitats populated by the species were described by the
vegetation and the location of the micro habitats in the general habitat. The observed adult
individuals and exuviae were counted. The inventories in a boat were carried out on the banks of
water bodies.
From 2001 to 2009 the oxbow lakes of the Gauja River were surveyed: 55 oxbows in the area
from Gaujiena to Inčukalns. 1-3 imago surveys were carried out in June-July (except for Tītmaņu
oxbow).
In May-October, 2005 in Tītmaņu oxbow, near Līgatne dragonfly (imago) survey was carried
out. The survey was carried out in 10 sample areas (each ~20-50 m 2 ) in various habitats (see
Figure 1). During the season 20 surveys were carried out in each sample area. The vegetation of
each area was described using Braun-Blanquet scale (Kent, Coker 1996).
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