220 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I4I 



unless live cockroaches were supplied. Parasitism was proved by de- 

 tecting radioactivity in mites that had fed on cockroaches which had 

 been previously fed radioactive NaCl (Cunliffe, 1952). 



The mites can destroy laboratory cultures of cockroaches (Piquett 

 and Fales, 1952; Edmunds, 1953a). A cockroach attacked by 25 

 mites succumbed after about an hour, falling on its back ; it died after 

 5 hours (Cunliffe, 1952). 



When found in homes and offices, these mites are an indication of 

 the presence of cockroaches ; the mite has been twice accused of biting 

 people (Baker et al., 1956). 



RECORDS OF UNIDENTIFIED MITES 



Natural hosts. — Aglaoptcryx fades, Puerto Rico (Sein, 1923) : 

 Four red "tick" nymphs found under wings of female. 



Blaberus craniifer, U.S.A., Florida (Hebard, 1917) : "A number of 

 lice [mites] are present on many of these specimens [28 ?$]." 



Blaberus discoidalis, adventive from West Indies, taken in Scotland 

 (Stewart, 1925) : A considerable number of mites were all over the 

 body and hind Vv^ings. 



Blatta orientalis, Germany (Cornelius, 1853) : Ex sexual organs 

 of male. 



Blattella germanica, U.S.A., in laboratory (Parker, 1939) : Under 

 conditions of high humidity, the cockroaches became heavily infested 

 with mites. In cages where the infestation was heavy, an abnormally 

 large number of females dropped their oothecae, and the percentage 

 of eggs hatching was low. 



Parcohlatta uhleriana, U.S.A., North Carolina (Hatcher, 1939) : 

 Hypopi of mites were found deeply embedded in the fat body of two 

 individuals. 



Mites in the hypopial stage attach to insects by which they are dis- 

 persed. Hypopi have been found in the gill chambers of a mollusk 

 and in the gonads of a millipede (Baker and Wharton, 1952). 



Periplaneta americana, U.S.A., in laboratory (Fisk, 195 1) : The 

 insects were sluggish and molted with difficulty. Gold Coast Colony 

 (Macfie, 1922) : Larvae of a tarsonemid mite were found in the feces. 



Pycnoscelus Surinam ensis, Hawaii (Illingworth, 191 5) : During the 

 summer the soil was literally swarming with young of various stages. 

 Early in September most of the adults were dead and all were covered 

 with mites. U.S.A., Connecticut, in laboratory (Zappe, 1918a). Ha- 

 waii, in laboratory (Schwabe, 1950) : Some of the cockroaches appar- 

 ently died from mite infestations. 



