Janus Pannonius Múzeum Évkönyve 39 (1994) (Pécs, 1995)

Természettudományok - Nógrádi Sára–Uherkovich Ákos: A magyarországi tegzesek (Trichoptera) elterjedése és gyakorisága az utóbbi évtizedben, számítógépes feldolgozás adatai alapján

67 Distribution and abundance of caddisflies (Trichoptera) in Hungary during the last decades based on computer data processing. Sára NÓGRÁDI and Ákos UHERKOVICH The expression of abundance of insects was always subjective or seemed to be subjective without correct arythmethical data. The qualification of the degree of abundance was influenced by the number of occurence in collections, the body size or wingspan, coloration and „overall beauty". Thus the larger, colorful animals with extreme pattern or form occur in collections more frequently than the small and grey animals. This symptom is striking in some old Hungarian Trichoptera collections. Most of them were created by non-trichopterologists thus the majority of their caddisfly material represents only a few families and species and do not give the true abundance in nature of these animals. When the cartography of European invertebrates started many decades ago (e. g. HEATH, LECLERQ 1969, HEATH 1971), the distributional data of some insect groups were revised in the respect of suitability for faunistic purpose and to express their abundance. Several data were not suitable to locate correctly on any modern map, because the collecting site was approximate, e. g. „Bükk Mountains" or „Bakony", or - sometimes - „N. Hungary" etc. Thus the importance to record correct data was recognized by the authors. Therefore correct and detailed locality and other data (collecting sites, habitats, number of specimens, sexes, etc.) were recorded from the beginning of eighties, that all the results should have been suitable for faunistic and écologie cartography. The authors strove to collect their material with quantitative method. Thus during their field work they captured, elaborated and recorded all specimens of all caddisfly species as far as possible. During the last twelwe saisons more than thousand field days were carried out, exceptional large material and data mass was gathered together. The „traditional" treatment of these data became impossibile. Therefore a computing program named „Field Diary Program" was developed for recording, retrieving and processing the data of Hungarian (and European) Trichoptera fauna. The program was developed for Commodore 64, but two years later the program was adopted for IBM PC/AT compatible computer. By the help of this program all the field data can be rather quickly and simply recorded. The following entries can be found in the data base: an identified number of locality (collecting site), its UTM grid, the datum, the collecting method and name of collector(s). The collected taxon, the number of males and females and their individual numbers are also given. All the data can be retrieved or can be corrected, completed and deleted. The processing part of the program can select, classify, list or compare data of the records. The results (lists, diagrams) can be printed out. This computing program is also suitable to process field and literature/collection data of other insects groups. By the help of „Field Diary Program" all the Trichoptera data collected by the authors were recorded. After twelwe years - when data more than half a million Trichoptera specimens have been recorded - important results were processed from this data base. Main results are as follows: Recorded species: Recorded localities: Number of occurences: Number of male specimens: Number of female specimens: Total individual number 188 650 36 361 197 976 336 713 534 689 The first aim of this paper is to introduce the natural („true") frequency of Hungarian caddisfly species in the last twelwe years, since the beginning of the authors' intensive studies on the Hungarian Trichoptera fauna. The first table presents the data listed above for all recorded species (188 of total 203 Trichoptera species of Hungary). In the text the evaluation of the results is given. Further tables (Tables 2-8) - the captions are also given in English - complete the Table 1 with summarizing the data of each families, the most frequent species on the base of individual numbers, occurences and collecting sites. The „degree of investigations" is also figured by tables and graphs. Additionally, distribution maps in UTM grid system and activity graphs conducted by the program are given as examples to introduce the multi-sided program (Figs 6-7). The distribution maps and activity graphs of all Hungarian Trichoptera will be published in the course of the coming years.