Abstract
Myrmecophilus americanus and Myrmecophilus albicinctus are typical myrmecophilous insects living inside ant nests. These species are ecologically important due to the obligate association with tramp ant species, including harmful invasive ant species. However, the taxonomy of these "white-banded ant crickets" is quite confused owing to a scarcity of useful external morphological characteristics. Recently, Myrmecophilus albicinctus was synonymized with Myrmecophilus americanus regardless of the apparent host use difference. To clarify taxonomical relationship between Myrmecophilus albicinctus and Myrmecophilus albicinctus, we reexamined morphological characteristics of both species mainly in the viewpoint of anatomy. Observation of genitalia parts, together with a few external body parts, revealed that Myrmecophilus albicinctus showed different tendency from them of Myrmecophilus americanus. Therefore, we recover Myrmecophilus albicinctus as a distinct species on the basis of the morphology.