The colony collapse disorder (CCD) has been a global problem for beekeepers and for agriculture, that depends on pollination. There are many known factors that arise the risk of CCD. The existence of Varroa destructor is considered as one of the most important factors endangering, that rises this risk. This parasitic mite can transmit a range of bee viruses such as varroasis. Moreover, the health of colonies depends also is affected by meteorological factors, specifically, the temperature and relative air humidity. We decide to combine these factors, thus, the aim of the bachelor thesis is to analyse how changes in temperature and relative air humidity affect the defence of Apis mellifera, L. against the varroa mites. We passed the natural fallout of varroa mite in the beehive of two honeybee lines, Apis mellifera carnica (Singer and Sklenár). We detected multilinear regression dependence of average day temperature, relative air humidity, and the total amount of fallen varroa mite per day after the application of Ekopol medicament and after the biotechnological control of varroa mite (removal of sealed drone broods). The experimental area is situated in central Slovakia in the village of Piešť II., the area of Horná Liešna, which belongs to the cadastral territory of Detva. The colonies are in insulated hives (B10 type) in two different weather conditions. The two hives are in Apihouse and the other two in the open area. The results of regression and correlation analysis showed a medium dependence of the varroa mite fallout on the air temperature. On the other hand, the dependence of the varroa mite fallout on relative air humidity has not significant. We detected significant differences in varroa mite infestation on honeybee in hives located on open are and those located in Apihouse.