Ricania speculum is called as black planthopper, belonging to the family Ricaniidae. We have determined a mitochondrial genome of fungal endosymbiont of R. speculum, belonging to the family Ophicocordycipitaceae. The circular mitogenome of this fungus is 66,785 bp including 32 protein-coding genes, 2 ribosomal RNA genes, and 19 transfer RNAs. Its GC ratio is 30.6\%. A phylogenetic tree presented that this fungus is clustered with fungi of two genera, Hirsutella and Ophiocordyceps.