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water. The vegetation is meadow motley grass, sedge and
reed.

In the temporary water holes with grassy vegetation
and moist soil we found numerous larvae and pupae of the
C. vexans and a smaller number of larvae and pupae of the
C. simulator, C. ustinovi, C. maritimus, C. reconditus,
C. punctatus. The temporary water holes with growths of
sedge exhibited the presence of larvae and pupae of the
C. simulator.

III. The valley

The valley of the Severskij Donetz river. In the area
under study the original (basic) shore line is not demarcated.
The width of the valley is from 4 to 26 km. The valley is
part of the sub-zone of the northern motley grass-fescue-
feather grass steppe. The soil is sandy, in some parts of
the valley there are artificial plantations of pine trees.

The following breeding areas are characteristic of the
valley; natural lakes - fresh salt, water, small, periodically
dry basins; various artificial water basins (pond-excavations,
sand quarries, irrigating canals, etc.) moist meadows, swamps,
sandy regions with copious and constant wetting.

1. Meadow that dries up during the summer months,
formed in place of overgrown lake. The vegetation is grass
where sedge is predominant. In small excavations we found
a few larvae and pupae belonging to nubeculosus Group.

2. Oxbow-lake. The oxbow lakes with silt or sandy
silt shores turned out to be areas of mass breeding of
midges of the C. riethi. C. puncticollis, C. nubeculosus and
groups of salinarius.

3. Artificially made lakes. These lakes are very
similar to the oxbow lakes as far as the conditions of the
habitat is concerned as well as the range of species of the
breeding midges.