Natural and experimental vectors.Blatta orientalis, Italy (Cao, 1898, 1906; Spinelli and Reitano, 1932).

Periplaneta americana, U.S.A. (Gier, 1947): The organism was pathogenic to the cockroach when injected.

† Spirillum periplaneticum Kunstler and Gineste

Habitat.Periplaneta americana, France? (Kunstler and Gineste, 1906): From intestinal tract.

† Spirillum α, β, and γ Dobell

Habitat.Blatta orientalis, England (Dobell, 1911, 1912): From hind gut.

Spirillum sp.

Habitat.Blatta orientalis, U.S.S.R. (Zasukhin, 1930): From intestinal tract.

Cockroaches, Venezuela (Tejera, 1926): From digestive tract.

* Vibrio comma (Schroeter) Winslow et al.