Two Cleptoparasitic Ant Crickets (Orthoptera: Myrmecophilidae) That Share Similar Host Ant Species Differentiate Their Habitat Use in Areas of Sympatry in Japan

Myrmecophilus crickets (Myrmecophilidae, Orthoptera) are typical ant guests. In Japan, about 10 species are recognized on the basis of morphological and molecular phylogenetic frameworks. We focused on two of these species, M. kinomurai and M. kubotai, and compared their host and habitat use. Previous work based on a limited sampling effort suggested that these two species share some ant species as hosts, but that their habitat (open versus shaded) preferences differ. Here, on the basis of exhaustive sampling across Japan, we confirmed that M. kinomurai and M. kubotai do not differ in their host ant preferences: both prefer formicine ants as hosts. As for habitat preferences, M. kubotai occurred significantly more often in open habitats than in shaded ones (P < 0.05). In contrast, M. kinomurai showed no habitat preference in areas where M. kubotai did not occur. However, M. kinomurai showed an obvious preference for shaded environments in areas of sympatry with its potential competitor M. kubotai. This pattern suggests that interspecific competition between M. kinomurai and M. Kubotai is a factor causing habitat differentiation in areas of sympatry.