232 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I4I 



information. However, Abeille de Perrin simply presumed that R. 

 boissyi parasitized E. pallidiis because he collected this cockroach in 

 the same habitat as the beetle. Abeille de Perrin suggested that the 

 species of the genus Ripidiiis lived in the bodies of cockroaches, but 

 there are no rearing records, as far as v^e know, oi R. boissyi from 

 cockroach hosts. 



Ripidius denisi Chobaut 



Chobaut (1919), in France, collected both R. denisi and Ectobius 

 pallidus when beating an oak tree. Because of the known association 

 of other species of Ripidius with cockroaches, he presumed that this 

 beetle was parasitic on E. pallidus, a cockroach common in this beetle's 

 habitat. 



Ripidius pectinicornis Thunberg 



Synonymy. — Symbius blattarum Sundevall [Leng, 1920]. 



Natural hosts. — Blattella gcrmanica, on shipboard (Sundevall, 

 1831) ; Germany (Aclogue and Fowler, in Burr, 1899a) ; on steam- 

 ship "Samui" (Stamm, 1936) ; on cruiser "Duguay-Trouin" (Bar- 

 bier, 1947) ; Hawaii (Williams, 1946a) : This last record was based 

 on a specimen dissected from an adult German cockroach collected on 

 an airplane from the South Pacific. The parasite was reported as 

 Ripidius sp. by Williams, but Weber ( 1948) made the specific identifi- 

 cation. 



Ectobius pallidus f Abeille de Perrin ( 1909) stated that R. pectini- 

 cornis was first described by Sunders [sic] as blattarum because it had 

 been captured in the body of Ectobia livida. We presume that Abeille 

 de Perrin was referring to Sundevall 's work in which the host was 

 given as Blattella germanica. 



Periplaneta americana, on shipboard (Sundevall, 1831) : One 

 nymph only. 



With the exception of the single nymph of P. americana, R. pectini- 

 cornis apparently attacks only adult females and nymphs of B. ger- 

 manica. Barbier (1947) found only B. gernmnica parasitized, al- 

 though both Blatta orien talis and Supella supcllcctilium were prevalent 

 on board the ship. Primary larvae of the parasite failed to parasitize 

 Supella. 



Adult behavior. — The winged male is relatively active compared to 

 the apterous female ; it runs around, flies well, and jumps on the fe- 

 male when in her vicinity. The female remains stationary and lays 

 eggs around her by bending her long ovipositor (Sundevall, 1831). 

 The eggs (50-100) are laid among a network of silk fibers secreted by 



