Imai, H. T.; Yosida, T. H. 1965. Chromosome observation in Japanese ants. Annual Report. National Institute of Genetics, Japan 15:64-66. PDF

Imai, H. T.; Yosida, T. H. 1966a. Chromosomes of male ants Aphaenogaster osimensis produced by parthenogenesis of workers. Annual Report. National Institute of Genetics, Japan 16:53-54.

Imai, H. T.; Yosida, T. H. 1966b. Polyploid cells observed in male and queen ants of Aphaenogaster osimensis. Annual Report. National Institute of Genetics, Japan 16:54.

Goñi, B.; Imai, H. T.; Kubota, M.; Kondo, M.; Yong, H.-S.; Tho, Y. P. 1982. Chromosome observations of tropical ants in western Malaysia and Singapore. Annual Report. National Institute of Genetics, Japan 32:71-73.

Goñi, B.; Zolessi, L. C. de; Imai, H. T. 1982. Chromosome observations of some Uruguayan ants (Hymenoptera: Formicidae). Annual Report. National Institute of Genetics, Japan 32:69-70.

Imai, H. T.; Brown, W. L., Jr.; Kubota, M.; Yong, H.-S.; Tho, Y. P. 1984. Chromosome observations on tropical ants from western Malaysia. II. Annual Report. National Institute of Genetics, Japan 34:66-69. PDF

Imai, H. T.; Kubota, M.; Brown, W. L., Jr.; Ihara, M.; Tohari, M.; Pranata, R. I. 1985. Chromosome observations on tropical ants from Indonesia. Annual Report. National Institute of Genetics, Japan 35:46-48. PDF

Imai, H. T. 1986a. Modes of species differentiation and karyotype alteration in ants and mammals. Annual Report. National Institute of Genetics, Japan 36:58-59.

Tjan, K. N.; Imai, H. T.; Kubota, M.; Brown, W. L., Jr.; Gotwald, W. H., Jr.; Yong, H.-S.; Leh, C. 1986. Chromosome observations of Sarawak ants. Annual Report. National Institute of Genetics, Japan 36:57.

Imai, H. T.; Taylor, R. W. 1986. The exceptionally low chromosome number n=2 in an Australian bulldog ant Myrmecia piliventris Smith. Annual Report. National Institute of Genetics, Japan 36:59-61. PDF

Imai, H. T.; Taylor, R. W.; Crozier, R. H.; Crosland, M. W. L.; Browning, G. P. 1988. Chromosomal polymorphism in the ant Myrmecia (pilosula) n=1. Annual Report. National Institute of Genetics, Japan 38:82-84.