Larvae feed on  leaves  of  cultivated  and  wild  banana  plants.  In  its  native  areas,  the  defoliation  of  banana  plants  is  usually  very  low,  but  in  non-native  areas  it  can  be  serious  during  outbreaks  and  favourable weather conditions. Complete defoliation has been reported sporadically.

The  Panel  concluded  that  it  is  not  possible  to  conduct  a  risk  assessment  on  E.  thrax  alone  because  of  uncertainties  with  its  taxonomy  and  the  general  confusion  in  the  literature  about  Erionota spp.  The  document  is  therefore,  in  effect,  not  a  risk  assessment  just  forE.  thrax  but  also  for  three  other  closely  related Erionota spp.  (E.  torus, E.  hiraca,  and  E.  surprisa).  The  judgements  made  by  the  Panel  –  if  not  specified  otherwise  –  thus  refer  to  all  four  of  these  closely related Erionota spp.