
            -4-

a large quantity of larvae and pupae of the C. nubeculosus,
<u>C. puncticollis</u>, <u>C. riethi</u>, <u>C. salinarius</u>, <u>C. circumscriptus</u>
and <u>C. manchuriensis.</u>

5. <u>The Kleban-byk river.</u> The 6 species of midges found
in the Bekhmut river were determined en masse on the littoral
section of this river and on the shores that were silted up
and bare of all vegetation.

6. <u>The Kolontaevskij river.</u> On the silted up sections
of the shore and in the accumulations of stringy algaewe
observed, en masse, larvae and pupae of the <u>C. riethi.</u>

For all the above determined biotops shallow depths
near the shores, very poor currents, silty soil (very often
denuded of vegetation) are characteristic. In swampy
regions we came across usual type of vegetation that are
characteristic of humid meadows and partially aqueous -
pond weeds, squatic jointweeds and duckweed.

The water in those rivers dirty, highly mineral and
muddy.

II. <u>Fluvial river plains</u>

<u>The fluvial of Severskij Donetz river.</u> The insect
breeding areas of this fluvial region, producing blood
sucking midges, were oxbow lakes, shallow drying up water
ponds in the lower beds, marshy flooded meadows with overdamp 
sections and slowly flowing brooks.

1. The marshy lakes are situated in the open section
of the fluvial plains and in the forests. An example of
one such area breeding the insects is a small and not very
deep marshy lake, elongated in its shape (30 x 10 m) highly
silted. The banks of this lake are overgrown with grass and
some shrubs. The specimens taken from such areas produced
the pre-imago phase of the <u>C. riethi</u>, <u>C. nubeculosus</u>, C.
<u>puncticollis</u>, <u>C. salinarius</u>, <u>C. manchuriensis</u>. In a lake
of a similar kind but smaller in size we have observed
larvae of the nubeculosus group in fairly sizeable quantities 
and some odd larvae of the salinarius group. A similar
        