Nicrophorus Fabricius, 1775, commonly known as necrophagous beetle, is associated with vertebrate carrion. Up to date, the genus consists of 72 species worldwide. In recent years, various phylogenetic studies explored on the evolution and relationship of the species in the genus. However, morphological and molecular phylogenetic studies produced conflicting results, continuing the problem over whether Nicrophrous quadraticollis is monotypic or not. The present study is to report the complete mitochondrial genome (mitogenome) of N. quadraticollis that was sequenced in prior to a systematic research of Silphinae. It was 17,747bp in length and comprised 12 protein-coding genes(PCGs), 2 rRNA Genes, 22 tRNA Genes and one non-coding region. The nucleotide composition is 40.9% for A, 36.7% for T, 9.0% for G and 13.4% for C.

Nicrophorus concolor Kraatz is a large burying beetle widely distributed in East Asia including Japan, and well known for the habit of burying dead small vertebrates to feed their offspring. Taxonomic research on hististomatid deutonymphs phoretic on this beetle has revealed that they are classified into seven distinct species all new to science, one of which was already described by us under the name Pelzneria uncinata. Now, we give an account of another new species of Pelzneria phoretic on N. concolor in Japan, mainland China and Taiwan. The deutonymphs of the new species are found frequently together with P. uncinata, but, unlike this species, in various, more or less cryptic places on the body surface of the beetle, which indicates that the new species does not show distinct preference of location on the host beetle. The present new species is easily distinguished from the known congeners by hysterosomal dorsum with anterior margin widely and arcuately protruded medially and crenate laterally, unusual forward displacement of dorsal hysterosomal setae d1, notably stout setae f, p and r on tarsus III, extremely long terminal seta e on tarsus IV, and so forth. The feeding stages of this mite are considered to feed on the carcasses of small vertebrates buried by adult N. concolor.