Voyager 2 observations of electrostatic electron and ion cyclotron har
monic waves in Neptune's magnetosphere are addressed. A model of elect
ron Bernstein modes generated by a loss cone distribution of superther
mal electrons is scaled to Neptune parameters and a comparison of theo
ry with the observed electron flux shows good agreement. A model of pr
oton Bernstein modes generated by a ring distribution of Tritonogenic
nitrogen ions is also investigated and satisfactory agreement with the
data are obtained compatible with known properties of the magnetosphe
re. The success of the model in accounting for electrostatic emissions
observed by Voyager over a wide range of sampled parameters recommend
s its general applicability to planetary magnetospheres.