A new genus and species of Rhizoecidae (Hemiptera, Sternorryncha, Coccomorpha) associated with Acropyga yaeyamensis (Hymenoptera, Formicidae, Formicinae).

Ishigakicoccus gen. n. shimadai sp. n. is described based on the adult female morphology. This new species was found in the nest of a rare Japanese ant, Acropyga yaeyamensis Terayama & Hashimoto, 1996, in Ishigaki Is., Japan. It resembles Capitisetella migrans (Green, 1933) and Pseudorhizoecus proximus Green, 1933. However, the new species differs from those two species in having small multilocular pores, large 3-5 locular pores on the medial area of ventral abdomen, and two different-sized body setae. This new species is also the first record of a potential trophobiont of Acropyga yaeyamensis. A key to Japanese species of Rhizoecidae is also provided.