Geographic Distribution and Niche Divergence of Two Stinkbugs, Parastrachia japonensis and Parastrachia nagaensis

Parastrachiidae is a small stinkbug family containing only one genus and two species, Parastrachia japonensis (Scott) (Hemiptera: Heteroptera: Pentatomoidea) and Parastrachia nagaensis Distant. The geographic distribution of the genus has been poorly studied. Niche conservatism refers to that idea that closely related species are more ecologically similar than would be expected, whereas niche divergence predicts they occupy distinct niche spaces. The existence of only two species within one genus suggests niche conservatism or differentiation might exist among them. Herein, the distribution of the genus was mapped, potential distributions were predicted using ecological niche modeling, and climate spaces occupied by the two species were identified and compared. Our outlined map supports the general spreading route proposed by Schaefer et al. The potential distributions suggest that the genus' range could extend beyond its presently known distribution, and further investigation into this area could aid in their conservation, particularly P. nagaensis. The niche space inferred by ecological niche modeling suggests the two species do not occupy identical habitat, but the differences between their models could simply be due to the differential availability of habitat in the different regions that they occupy.