EN
The aim of the work was to check whether Varroa destructor mites parasitizing brood developing in standard size cells (5.4 mm) (STC) and in small size cells (4.9 mm) (SMC) differed in the sequence of the cytochrome oxidase I gene fragment (CO I) and body size. Two mite groups were formed (100 specimens in each); the mites parasitized brood developing in STC and SMC combs. Six mite specimens from the STC and 6 from SMC were subject to genetic analyses. Morphometric measurements involved 94 mites both from STC and SMC groups. The small cell size in the honeycomb (4.9 mm) did not affect the sequence of the CO I gene fragment in Varroa destructor, but led to significant reduction in their body size, possibly as a response to the limited space in the cell.