Teratorhabditis synpapillata, originally described from cow dung in Bali, was isolated from the red palm weevil, Rhynchophorus ferrugineus, in Japan. Dauer juveniles were isolated from beneath the elytra of five specimens of R. ferrugineus that had emerged from a dead Canary Island date palm, Phoenix canariensis, in Kagoshima, Japan. The dauer juveniles were cultured on a NGM agar plate and the adult nematodes observed and measured with the aid of light microscopy. The full length of the ribosomal small subunit (SSU) and D2/D3 expansion segment of the ribosomal large subunit (LSU) were sequenced for molecular identification. Based upon morphology, molecular profile and a hybridisation test, the nematode was confirmed as T. synpapillata. A comparison of morphology and morphometrics suggests that the only other nematode reported from R. ferrugineus (= 'Pelodera rhynchophori') is also conspecific with T. synpapillata. A phylogenetic analysis using SSU and LSU rRNA gene sequences fully resolves the relationships of four Teratorhabditis and six outgroup species and demonstrates a sister group relationship of T. synpapillata and T. palmarum, another associate of palm weevils.