All known species of Hexantheda are thought to specialize on plants belonging to Petunia or its close relative Calibrachoa (Solanaceae)
References
ROIG-ALSINA, A. 2006a. A new species of Hexantheda Ogloblin (Hymenoptera, Colletidae), a genus of bees with labial palpi of variable number of segments. Zootaxa 1229: 33-40
COMPAGNUCCI, L. A. 2014. Colletidae. En Roig-Juñent, S.; L.E. Claps & J.J. Morrone (Directores). Biodiversidad de Artrópodos Argentinos Volumen 4. Páginas 221-236.. Editorial INSUE -UNT, San Miguel de Tucumán, Argentina.