Chromosomes of the Pycnoscelus Indicus and P. Surinamensis Complex (Blattaria: Blaberidae: Pycnoscelinae)

The chromosome numbers of both parthenogenetic and bisexual forms of Pycnoscelus surinamensis (L..) have been reported to be 38 () and 37 o by Matthey I945, specimens from the botanical garden and crocodile house in Berlin; I948, specimens rom Kuala Lumpur, Malaya), and 36 ( parthenogenetic) by Suoma.lainen (I945, specimens from the botanical garden and crocodile house in Berlin). Reproductive behavior (Roth and Willis, I968), and crossing experiments (Roth, I967) have shown that the parthenogenetic and bisexual "strains" are physiologically sexually isolated from one another and Roth (I967) applied the name Pycnoscelus indicus (F.) to the’ bisexual taxon from which the parthenogenetic form (P. surinamensis) apparently arose. The specimens used in the I967 study originated from Florida, Hawaii, Australia, and Indonesia. In this paper we report the results of a study of the numbers and morphology of the chromosomes of P. indicus, and clones of P. surinamensis from different geographical areas. Pycnoscelus surinamensis is cosmopolitan, whereas P. indicus appear.s to. be restricted mainly to the Indo-Malayan region.