Somogyi Múzeumok Közleményei 13. (1998)

Ábrahám Levente: Tanulmány a hazai vízi életmódú recésszárnyú faunáról (Neuroptera: Osmylidae, Sisyridae)

HUNGARIAN FRESHWATER OSMILYD AND SPONGE-FLIES FAUNA 271 lected near the lower courses of the Danube or the Tisza; on the other hand it was abundant in light trap samples at Őrtilos next to the Drava River (ÁBRAHÁM 1995). Seasonal activity graph is shown in Fig. 8. The characteristic habitats of Sisyra terminális are in running water: large rivers, rivulets, streams and in stagnant water: gravel pits, reservoirs, stagnant river .branches, water body with temporary in-flow, lakes, ponds. Sisyra jutlandica Esben-Petersen, 1915 At present, categorisation of the faunaelement of this species can not be stated yet, as its distribution is not sufficiently known. It appears only in Europe, mainly in the countries of the Baltic basin. An isolated population of the species was first discovered at lllmnitz (HÖLZEL et al. 1980) near Lake Fertö in Austria. At first the species was recorded at Megyer next to the Marcal river (ÁBRAHÁM 1989) in Hungary, it also occurred in Szigetköz near the Danube river region in northwest Hungary (SZIRÁKI 1997). Sisyra jutlandica seems to belong to bivoltin species, its life cycle is being studied by WEISSMAIR (1994b). Its characteristic habitats are stagnant waters: littoral lakes, shallow ponds, running waters: rivers, rivulets. The population in the Little Hungarian Plain (Kisalföld) in Hungary is very significant both from zoogeographically and nature conservation points. In Hungary it has not been protected by law yet. Data concerning the appearances of the imagines

1 were examined by different methods as suggested by MONTGOMERY (1942) SOÓS (1958) DÉVAI (1976) BENEDEK - JÁSZAI (1971). According to the assumption, the diagram of seasonal activity of imagines should reveal normal distribution. However, due to few sample materials, the above statement could not be proved statistically by data of imagines used in this study. As a matter of fact, the activity graph from the few available data were unsatisfactory, so another method was presented. Seasonal activity graphs as shown in Figs.: 2. 5. 8. were drawn considering each region in Hungary and the days and months of their appearance marked along the time line. The first and last dots inform us about start and end of seasonal activity while density of dots point out the frequency of seasonal activity of imagines, while the dots density and their connection to each other show the probable increase of collected specimens. Data on the activity graph gives information on microclimatological changes of the different collection sites. Seasonal activity of Osmylus fulvicephalus on the south slopes of the Mecsek Mountains and the Aggteleki Karszt, for instance, begins earlier than on the northern slopes of the same region, which are microclimatologically colder. All those specimens collected in the Mecsek Mountains in the first decade of August live in cooler habitat for example: Komló Mánfa Kőlyuk, Komló Mánfa Nagymély valley, Püspökszentlászló. As shown in figure: 2. seasonal activity is influenced by latitude and geographical position of collection site in Hungary. A very simple examination was carried out to study the daytime activity of Hungarian freshwater neuropteroid fauna. It gives information on their collection possibilities and the distribution of the collected materials. All movement types were recorded to define the absolute frequency of their activities. Three movement types were registered for agile antenna movement in resting position, walking and flying. At the end activity graphs were compared with types of flight activity patterns showed by DUELLI (1986). New information can be concluded from these results on freshwater neuropteroids concerning day and night activities. Activity pattern of Osmylus fulvicephalus belongs to carnea type and it is listed as nocturnal activity. Sisyra fuscata and Sisyra terminális seem to belong to basalis type characterised by two activity peaks at dawn and at dusk. Activity patterns are strongly modified by temperature changes in nature. Besides, we must take into consideration the homeostasis of insect as well. Seeing the last two diagrams on Sisyra species, the hypothesis, saying that basalis type flying activity patterns with two peaks at dusk and at dawn is probably a consequence of the island habitat must be rejected, based on the results of experiments on the Sisyra species in Hungary. None of them are protected in Hungary yet, although these species are listed in Red Books in some of the neighbouring countries (Austria, Slovenia, Germany). 1 Terminology used in Hungarian literature is sometimes confusing, as it also happens with the English literature. Words and phrases denoting seasonal activity are as follows: flight activity, time-distribution of adults, appearances of imagines, phenology, voltinims. Phenology and voltinims are not used correctly, the first meaning the complete description of life history and is not limited to the flight activity of the imagines , the latter referring to the entire life cycle. Words and phrases used for day and night activity are: flight activity, and flight activity patterns. Sok publikáció helytelenül a fenológia szót alkalmazza a rajzási adatok ismertetésekor. A fenológia a fejlődésmenet teljes leírása és nem korlátozódik az imágók repülési aktivitására. A vizsgálat csak az imágókra terjedt ki, éppen ezért a teljes egyedfejlődés időbeli lefutására csak következtetni tudunk. A repülési aktivitás, rajzási aktivitás, szezonális aktivitás és a helytelenül használt fenológia szó is ugyanazt a jelenséget takarja. A napi mozgás aktivitásra, mint szinonim megfelelőjét használják a repülési aktivitás szót is a magyarban, de emellett e fogalmat alkalmazzuk a gyűjtések során az állatok abudancia viszonyainak megjelölésére is.