Ábrahám Levente: Biomonitoring a Dráva folyó magyarországi szakasza mentén 2000-2004 - Natura Somogyiensis 7. (Kaposvár, 2005)

Ábrahám, Levente.: Biomonitoring of the butterfly fauna in the Drava region (Lepidoptera: Diurna) - Nappali lepkék biomonitoring vizsgálata a Dráva mentén (Lepidoptera: Diurna)

•57 (Bélavár, Vízvár, Babócsa), while the population trend is less likely to follow this tendency near Ortilos. This deviance might be explained by the small size of the researched population, as even minor changes in the small number of counted specimen - which can just as well be caused by the current local weather conditions - can appear as bigger scale changes on the timeline trend diagram. Maculinea teleius and Maculinea nausithous The monitoring of species on the field near Lankóci forests (Gyékényes) has been ongoing for four years continuously. The research work shows different tendencies in the relative population changes of the two investigated species (Fig. 4.). Maculinea teleius population reached its biggest size in 2001, and showed roughly the same size in 2002 and in 2003. The year 2004 brought a slight decrease in comparison to the previous years. Maculinea nausithous population near Gyékényes has shown hardly any considerable change in size during the four years of research (Fig. 4.). This species tends to occur on the shady, half shady edges on the sampling sites. However, during the nectar feeding period, the imagoes can be encountered in any transects. Lycaena dispar In the case of this species, during the biomonitoring program, only presence-absence data was collected along the River Drava. In the course of the fieldwork, the sampling sites were located by GPS equipment. Among the recorded data only the data related to the first generation is significant from environmental point of view. The specimens from the second generation live a migrating lifestyle and therefore they tend to occur far from their actual habitat. This kind of data cannot be used to determine the trends but in the Fig. 4.: The time trends of Maculinea teleius and Maculinea nausithous population at the permanent sampling sites.