Dr. Holló Ferenc szerk.: Parasitologia Hungarica 3. (Budapest, 1970)

of essentially more watery sites, even after the passing of high water, than one-sixth of the originally inundated territory, and by the appearance, according to our observations

, of the mosquito imagos two weeks earlier than either in the Bend or on the Csepel Island. The explanation is that the insolation curve reaches its maximum generally sooner at the height of Dunaujváros-Tass than in the area north of this line. These observations refer to experiences gained from the „customary" or standard floods of the Danube; the flood of 1965 broke all previous records, both as to its duration and height. It will be remembered that the water level of the Danube was almost uninterruptedly very high beginning with the middle of April, 1965. The contiguously high water level refuted a number of assumptions and yielded some valuable new experiences (SZABÓ et ZOITAI, 1967). It'is known that a considerable part of the agricultural territory of Hungary is situated in formerly inundated areas. Human intervention had considerably influenced also the life of mosquito species breeding in the flooded regions, having to a large extent diminished the number and size of the breeding localities. According to our investigations, the breeding sites, discovered during the preceding years, had in 1965 been flooded without exception by water (1-4 m deep) and then covered by a rather thick layer of flood drift (mainly sand and silt). The prolonged combined effects of these two factors resulted in our failing to find any significant mosquito breeding site in the area between the dams. Midge larvae (Chironomidae

) had, however, breeded in astonishing numbers, and the swarming clouds of the imagos gave the impression of a mosquito plague in many places. The panic was caused by Boophthora erythrocephala whose attacking swarms evoked many reactions of an allergic nature in the men working on the dykes. On the other hand, mosquito larvae bred In numerous sites in the shallow, grassy pools caused by up-welling or oozing waters beyond the dams. The pools had in general been rather small. Although most of the observed breeding sites appeared in places