It's another butterfly - smaller and much less conspicuous than its relative which I wrote about this week - yet just as beautiful and interesting. According to Sammut's definitive book on the Maltese butterflies and moths, this is Syntarucus pirithous (L., 1767), which is frequently encountered throughout the warm season.
Reference:
Sammut, P., 2000. Il-Lepidoptera. Kullana Kulturali, 12: 1-246. Malta: Pubblikazzjonijiet Indipendenza.