
Italicus is a floral liqueur built on bergamot and other botanicals, with a bright citrus-herbal character.
Another bergamot liqueur
The closest flavor match, like Quaglia. However, at 35% it will make a noticeably stronger drink.
St-Germain
Swap it in straight. Expect a sweeter, more floral result.
The easiest to find, and the sugar is about the same. Use the same measure, though lemon replaces the bergamot and the floral notes vanish.
A citrus liqueur with strong Earl Grey
A clever backup. The tea is flavored with bergamot oil, bringing that lost note back. Add it half a barspoon at a time, or the tea makes things astringent.
Built on bergamot and cedro citrus from Calabria and Sicily, with chamomile, lavender and gentian behind them. That is why a floral, bitter edge stays after the citrus. At 20% it is a modifier, and it carries enough sugar that a drink that uses a lot of it rarely needs syrup as well.