Szekessy Vilmos (szerk.): A Magyar Természettudományi Múzeum évkönyve 59. (Budapest 1967)

Mihály, F.: Seasonal distribution of the synanthropic flies in Hungary

ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Tomus 59. PARS ZOOLOGICA 1967. Seasonal Distribution of the Synanthropic Flies in Hungary By F. MIHÁLYI, Budapest In clearing the role of flies in the transmission of enteric diseases it is absolutely essential to know the seasonal abundance of the synanthropic species. Therefore I compiled in tables the data of my synanthropic fly material, collected in 1959—66, counting those data only which could be evaluated quantitatively, that is which were caught by traps exposed for a known lenght of time. I give these data in half month periods, taking separately those caught on human faeces (ex), meat (m), and fruit (fr). These numbers depend not only on the density of the species but also on the number and hours of exposure of the traps. Of the main species collected in greater number also abundance graphs were constructed. The data for this graphs were calculated by dividing the absolute numbers of the flies by the trap-hour numbers. Thus I got the average number of flies visiting a single trap in one hour, which indicates the density of the species in question. The 19 abundance graphs show the seasonal distribution of 20 fly species. Of these graphs one can also conclude on the number of generations in one year, keeping in mind that the generations are partly overlapping after the second one. Collections were made by the collapsible GREGOR-POVOLNY traps, baited with human faeces, meat, and fruit. The lesser part of the collections were made in inhabited areas, the bulk of it in free nature. That is the cause why some essential species of the domestic fauna were collected in small numbers only. Thus only a few Musca domestica L. got into the traps even in village courtyards, and Stomoxys calcitrans L. is nearly missing. The number of Muscina stabulans FALL, caught in traps was also too low to allow the compilation of an abundance graph. The families in the text and in the tables are not treated according their systematic order, but according their significance. The most dangerous species of the Tachinidae (s. lat.) belong to the Calliphorinae (Table 1). Cailiphora vicina R.-D. ( = erythrocephala MEIG.). Its abundance graph (Fig. 1) shows a maximum in the spring and one in the autumn. During the summer, its number diminishes and, according to SYCHEVSKAYA (1965), the ovaries of this species become inactive in the hot summer months. In autumn, they lay eggs again. In my cultures, kept out of door, flies hatched till December 21, and, after a winter diapausa, from March 30 again. The species lives in Hungary mainly in inhabited areas. Cailiphora vomitoria L. Its abundance curve (Fig. 2) is like that of the former species, but has a more pronounced summer diapausa. Living mainly in forests, it is rare in inhabited areas.