The use of Allodonta is a bit messy. Schintlmeister & Lourens (2010: The Notodontidae of the Philippines; hereafter S&P 2010) used Hexafrenum as a subgenus of Allodonta - this was the first such instance of use and they didn't state it was a new usage (subgenus nov) and that the subseqent change of combination for the constituent species previously in Hexafrenum should have been stated as either comb. nov. (new combination) or comb. rev. (revived combination), but didn't. Technically, one could argue the change hasn't been properly notified, and thus hasn't happened. (ouch) I will ignore this minor technicality! Holloway (Moths of Borneo, part 2; 2011) also noted the change by S&P2010 demoting Hexafrenum to subgenus.