Proto-Indo-European *bʰluseh₂

→ Belarusian блыха (inherited)

→ Bulgarian бълха (inherited)

→ Czech blecha (derived)

→ Lower Sorbian pcha (inherited)

→ Lower Sorbian bcha (inherited)

→ Upper Sorbian pcha (inherited)

→ Upper Sorbian tcha (derived)

→ Old East Slavic блъха (inherited)

→ Polish pchła (mention)

→ Russian блоха (inherited)

→ Serbo-Croatian бувљак (mention)

→ Slovene bolha (derived)

→ Ukrainian блоха (derived)

→ Slovincian pχlȧ̃ (inherited)