title: Species clarification of Ogasawara cockroaches which inhabit Japan.
abstract: The so-called "Ogasawara cockroaches" were examined by morphological observations and by breeding experiments to elucidate their actual taxonomical status. Fourteen groups (isolate) of "Ogasawara cockroaches" collected from Iwoto-A, Iwoto-B, Hahajima, Chichijima, Nishijima, Nakodojima, Tokunoshima-A, Tokunoshima-B, Okinawato- A, Okinawa-B, Amamiooshima, Miyakojima, Ishigakijima and Hawaii, were bred and passaged in our laboratory. Cockroaches collected from the field were first reared individually and the sexes of their offspring examined. Cockroaches collected from Iwoto, Tokushima and Okinawa, were found to consist of two groups; those whose offspring were all female and the other whose offspring consist of both male and female. Cross-breeding experiments showed that individuals from the group that did not produce any male but only female offspring were parthenogenetic. On the contrary, the group that have bisexual individuals produced both male and female offspring in a ratio of 1:1. Our results show that the so-called "Ogasawara cockroaches" consist of 2 species, namely, Pycnoscelus surinamensis and Pycnoscelus indicus. There are areas in which both species co-habitated together and there are also areas in which either only one of the two species can be found. The group that reproduces only female offspring and only through parthenogenesis was identified as P. surinamensis. The group that reproduces heterosexually and produce male and female offspring was identified as P. indicus. Thus, the so-called "Ogasawara cockroaches" found in Japan actually consist of 2 species, namely, P. surinamensis and P. indicus, which can be differentiated using the solitary breeding method to demonstrate parthenogenesis in the former and the need for sexual reproduction in the latter.
authors: Civil International Corporation, 1-10-14 Kitaueno, Taito, Tokyo 110-0014 Japan.
authors: N
authors: N
authors: Komatsu
authors: Laboratory of Parasitology, School of Life and Environmental Science, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 252-5201 Japan.
authors: Y
authors: Y
authors: Kawakami
authors: Laboratory of Parasitology, School of Life and Environmental Science, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 252-5201 Japan.
authors: A
authors: A
authors: Banzai
authors: Laboratory of Parasitology, School of Veterinary Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 252-5201 Japan.
authors: H K
authors: HK
authors: Ooi
authors: Yamazaki Gakuen University, 4-7-2 Minami-osawa, Hachioji, Tokyo 192-0364 Japan.
authors: A
authors: A
authors: Uchida
mesh_terms: D000818:Animals; D003058:Cockroaches / Q000033:anatomy & histology / Q000145:classification* / Q000502:physiology; D005260:Female; D006824:Hybridization, Genetic; D007564:Japan; D008297:Male; D008853:Microscopy; D010312:Parthenogenesis