BIOTIC ASSOCIATIONS OF COCKROACHES — ROTH & WILLIS I97 



and Ackert, 1934) var. Indiana; L. appendiculata (Leidy, 1852) 

 (Chitwood, 1932) var. americana; L. appendiculata (Serrano San- 

 chez, 1947) var. hispana. However, Basir (1956) does not recognize 

 these varieties. The Russians recognize hispana (M. B. Chitwood, 

 personal communication, 1957). 



Natural hosts. — Blahcnis atropos, South America (Chitwood, 



1932). 



Blatta orientalis, Egypt? (Caleb, 1878) ; Europe (Biitschli, 1871) ; 

 U.S.S.R. (Sobolev, 1937; Sondak, 1935) ; U.S.A., Nebraska (Todd, 

 1944) ; Spain (Serrano Sanchez, 1947) : Recorded as var. hispana. 

 Czechoslovakia (Groschaft, 1956). England (Lee, 1958a). 



Blatta orientalis or Periplaneta americana, Brazil (Magalhaes, 

 1900). 



Periplaneta americana, U.S.A.: Texas (Todd, 1943); Nebraska 

 (Todd, 1944) ; Kansas (Dobrovolny, 1933; Dobrovolny and Ackert, 

 1934) ; North Carolina (Hatcher, 1939) ; Iowa, North Dakota, Michi- 

 gan (Hoffman, 1953). Czechoslovakia (Groschaft, 1956). Eng- 

 land (Lee, 1958a). 



Cockroach, Venezuela (Tejera, 1926). 



Cockroaches (Blatta orientalis, Blattella germanica, and/or Peri- 

 planeta americana) , U.S.A. (McAdow, 1931). 



Chitwood (1932) also listed China for distribution of the worm, but 

 we could not tell which host was involved. 



The worms are found in the colon and rectum of the host. Caleb 

 (1878) found as many as 20 individuals in a single B. orientalis. 

 Sobolev (1937) found 52 percent of B. orientalis infected with L. 

 appendiculata; the mean number of worms per roach was 1.5 and the 

 maximum 2. Dobrovolny and Ackert (1934) found 69 percent of 222 

 P. americana infected with this species. 



Two molts occur within the tgg during development of the larva. 

 The first molt occurs outside the host resulting in the formation of an 

 infective resting stage. The second molt occurs inside the cockroach 

 (Todd, 1941, 1944). 



Transmission of the nematode is direct, eggs in the resting em- 

 bryonated stage being infective (Dobrovolny and Ackert, 1934). 



Hoffman (1953) described a filamentous bacterium, Streptomyces 

 leidynematis Hoffman, which grows on the cuticle of L. appendiculata 

 in P. americana. Leidy (1853) noted the presence of simple, inarticu- 

 late, amorphous filaments, growing from nematodes infecting B. ori- 

 entalis. Biitschli (1871) and Magalhaes (1900) described similar 

 filaments adhering to the surface of oxyurids from cockroaches. 



