S. Mahunka szerk.: Folia Entomologica Hungarica 49. (Budapest, 1988)

Plecoptera Capnia bifrons (Newman, 1839): 13.03. 7 3, 7 c-, 17.03. 5 S, 2 cj>, 12.04. 5 3, 4 ç, 13.04. 1 3, 03.05. 1 3. .Szentlászló Valley and Apátkut Valley. One of the earliest insects. It often occurs even on the snow. Larvae develop on the upper part of Szentlászló Valley. Leuctra pseudosignifera (Aubert, 1954): 13.03. 2 3, 1 p, Szentlászló Valley, 02. 04. 1 3. Imagos were captured by the author on the upper, cleaner part of the stream. Leuctra digitata (Kempny, 1899): 18.10. 2 3, 1 <j> Szentlászló Valley and Apátkut Valley, 30. 10. 3 3, 5 o, Ördögbánya. Protonemoura intricata (Ris, 1902): 21.01. 5 3, ördögbánya. Nemoura flexuosa (Aubert, 1949): 12.04. 3 6, 5 13.04. 1 3, 17. 04. 3 3. Apátkut Valley and Szentlászló Valley. Nemoura sciurus (Aubert. 1949): 12.04. 8 3, Szentlászló Valley, 13.04. 1 3, 17.04. 1 3, ördögbánya, 10.05. 7 3. Apátkut Valley, 25.05. 1 3, 30.05. 1 3. Ördögbánya. Nemoura cambrica (Stephens, 1835): 12.04. 5 S, 10.05. 2 ó\ Apátkut Valley. N

emurella picteti (Klapálek, 1900): 12.04. 4 3, 2 <j>, Apátkut Valley and Szentlászló Valley, 12.06. 1 3, Apátkut Valley. Isoperla tripartita (lilies, 1954): 10.05. 5 3, Apátkut Valley, 17.05. 1 3, 2 25.05. 2 ?

. Chloroperla tripunctata (Scopoli, 1763): 13.04. 1 <j>, Szentlászló Valley, Apátkut Valley, 10.05. 1 o., 17.05. 3 25.05. 5 3, 5 ç. Perla burmeisteriana (Classen, 1936): 10.05. 1 3, 4 (j>, Apátkut Valley (Ördögbánya). CONSEQUENCES 16 species of Ephemeroptera and 11 species of Plecoptera were found in one of the permanent streams of Visegrád Mountains. Imagos were the most abundant in species number flying mainly on parts from the River Danube and at Ördögbánya, in the Apátkut Valley. Sedimentary or standing water-dwelling Caenis species and Cloeon dipterum were captured around the artificial trout ponds, after the hunting box. Ecdyonurus starmachi (Sowa, 1971) was proved to be new for the Hungarian fauna. In the Apátkut Stream this species prefers parts with higher waterspeed. Altitude of localities was a little bit lower than that the Polish localities (200-700 ms above the sea level), larvae were found at a waterspeed of 0. 3-2. 0 m sec" Flying season of imagos was from May to Sept. and they were inclined to fly towards light as well. Distinguishing characters of males and females correspond to the Polish descriptions (Fig. 2). An other interesting faunistical data is the occurrence of Caenis luctuosa (Burmeister, 1839), that is new for the Hungarian fauna. This species belongs to the Caenis macruragroup and it seems to live in smaller lakes, at lower altitudes. Among Plecoptera, Leuctra pseudo signifera is a new species for the Visegrád Mountains (up to now this species has been found only in the Börzsöny Mountains). Its occurrence indicates the close zoogeographical relationship of the two mountains. It is a rare species, that occurs both in the Alps and in Central Europe at higher altitudes. It occurs extrazonallv on the deep gorge of Szentlászló Valley, at lower altitude. Leuctra digitata

, being common 1 in Scandinavia, is also new for the Visegrád Mountains. It is a boreo-alpine species occurring in Hungary in the deep parts of the Apátkut Valley, that are surrounded by beech-trees and have a cold microclimate. By covering the whole area it made a detailed analysis of the distribution of Ephemeroptera and Plecoptera species possible. Species of both groups live only in the Szentlászló Valley and in the Apátkut Valley, leaving the source of the stream, and most of the species occur in the deep, stony parts. The imago fauna is represented by only a new species at the source at Pilisszentlászló, and in a small degree at Visegrád, these facts can presumably be explained by anthropogenic effects. According to the prevailing investigations carried out by the author, Ecdyonurus and Rhithrogena species do not fit in the species given by Hungarian taxonomic books (ÚJHELYI