Despite its circum-tropical distribution, we report, for the first time in Italy and Sicily, the presence of Megalorhipida leucodactyla (Fabricius 1974), a species recorded only once before in Europe. Several adults, pupae and larvae of different instars were found on Boerhavia repens L. ssp. viscosa (Choisy) Maire (Nyctaginaceae), recorded for the first time in Italy (Sicily) in 1967. We provide both an update of Boerhavia repens ssp. viscosa's distribution in Sicily and the results of our vegetational survey, based upon the phytosociological method by Braun-Blanquet Sigmatist School, on Boerhavia repens ssp. viscosa in Palermo city's urban areas. This plant, naturalised especially in Palermo city, appears to have become an invasive plant, increasingly spreading in larger areas, by even replacing the native flora in urban ecosystems. This study also provides the results of laboratory bioethological observations on some specimen of both adults and larvae (the latter while feeding on Boerhavia repens ssp. viscosa's fruits). Finally, using bibliographic data, we drew a map of the distribution of both Megalorhipida leucodactyla and Boerhavia repens ssp. viscosa in the Mediterranean basin.