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

our inve*stigations

, one or two larger (about 2200 cy) and three to four smaller (about 100-700 cy) mosquite breeding sites should annua]. 1 y be reckoned with. We have also observed that the sandy soil of the region will, subsequent to the passing of the flood, absorb most of the remaining pools of water so that the surface of waters actually producing mosquitos shrinks to about one-sixth of the originally inundated area.This statement holds, subject to minor corrections, to the entire Hungarian reach of the Danube. This observation might have its true importance in the chemical treatment of the breeding sites, would this indubitably effective and cheap means of control be favoured by the national and local authorities executing the preventive measures. It is an old experience (ZOLTAI, 1957) that in the mosquito breeding sites of the inundation areas the larvae of the mosquito species congregate of a comparatively small water surface;accordingly,their chemical control involves a relatively small financial outlay.The formation of the breeding sites and breeding should be under constant observation for a well-timed Intervention. Work and the transport of materials and control devices are more difficult on an already soaked soil; the protection of young fish also contradicts this late control. This is why the less effective and considerably more expensive mechanical control is favoured all over the world, despite the further drawback of the unselective effects of the chemicals applied. They are deadly for all insect specimens arriving in the region under treatment. And hardly any investigation has as yet been made on the connections and interactions of the entomofaunas of flood areas.Is it not premature to apply drastic control measures in a habitat whose life is not sufficiently known even in outlines (NAGY, 1966)? According to our investigations, there are two rather extensive breeding sites in the Bend: one between the southern end of the Szentendre Isle and Szigetmonostor, the other on the northern tip of the Island (on both sides), between Kisoroszi and Tahitó tfalu. Two other breeding sites, in the environs of Budakalász and Surány, are also worthy of mention. Of the latter two