The paper presents data on the first records of Dendroxena quadrimaculata (Scopoli, 1771) in the Tyumen region. D. quadrimaculata is distributed in the European part of Russia, Caucasus and south of Siberia. This species was not previously recorded in the Tyumen region, but within two years (2018–2019), it spread throughout the region. We considered the possible reasons for its range expansion in Western Siberia.