Introgression and Habitat Segregation in a Pair of Ladybird Beetle Species in the Genus Propylea (Coccinellidae, Coccinellinae) in Northern Japan Suga, Hiromu and Hirano, Wataru and Katoh, Toru and Matsubayashi, Kei W. and Katakura, Haruo, Zoological Science, 33, 603-610 (2016), DOI:http://dx.doi.org/10.2108/zs160062