The cockroaches Cryptocercus and Panesthia both feed on wood, but the protozoa found in Panesthia resemble more closely the species in domestic cockroaches than those in Cryptocercus. The Clevelandellidae (from Panesthia) are closely related to Nyctotherus and have probably evolved from common ancestors. However, the separation of the Clevelandellidae from Nyctotherus must have taken place at a later date than the divergence of their hosts, otherwise representatives of that family would probably also be found in Periplaneta and Blatta (Kidder, 1937).
The protozoa of Cryptocercus can be transferred from one individual to another (Nutting and Cleveland, 1954). They can also be transferred to the termite Zootermopsis where they survive only until the host molts; the reverse is also true, Zootermopsis Protozoa can survive in Cryptocercus until the cockroach molts (Nutting and Cleveland, 1954a).
[VI. VIRUSES ASSOCIATED WITH COCKROACHES]
Annotations on some of the following observations may be found in Roth and Willis (1957a). Use of asterisk is explained in footnote [3], page [4].
POLIOMYELITIS VIRUSES
* Lansing strain
Experimental vectors.—Blattella germanica, U.S.A. (Hurlbutt, 1949, 1950).
Periplaneta americana, U.S.A. (Hsiang et al., 1952).