BIOTIC ASSOCIATIONS OF COCKROACHES — ROTH & WILLIS 2ig 



Family PODAPOLIPODIDAE 



Locustacarus sp. 



Natural hosts. — Diploptera punctata and Nauphoeta cinerea, U.S.A. 

 (Roth and Willis, unpublished data, 1954) : Mite genus determined 

 by Dr. E. W. Baker (personal communication, 1954). The mites 

 cluster thickly on intersegmental membranes, particularly around the 

 coxae and neck. Despite a heavy infestation, the colony of Nauphoeta 

 thrived for several years. This mite was found first on N. cinerea and 

 possibly transferred to D. punctata when the latter was brought into 

 the laboratory from Hawaii. 



Family lOLINIDAE 



lolina nana Pritchard 



Natural hosts. — Blaberus craniifer (originally from a culture at 

 Harvard University) and Diploptera punctata (originally from 

 Hawaii), U.S.A., Pennsylvania (Roth and Willis, unpublished data, 

 1953 ; Pritchard, 1956) : The mites usually attached near the wing 

 bases of the insects. Morphologically, the species is intermediate be- 

 tween certain predaceous and phytophagous mites (Pritchard, 1956). 



Family PTERYGOSOMIDAE 

 Pimeliaphilus podapolipophagus Tragardh 



Common name. — Cockroach mite. 



Natural hosts. — Parcoblatta sp., U.S.A. (Edmunds, 1953a). 



Periplaneta americana, U.S.A. (Piquett and Fales, 1952). 



Cockroaches. U.S.A. (Baker and Wharton, 1952). 



Experimental hosts. — Blatta orientalis, Blattella germanica, and 

 Periplaneta americana, U.S.A. (CunliflFe, 1952). 



Eggs of this mite (fig. 4) are usually laid indiscriminately in the 

 rearing cages, rarely on the host. Eggs are coated with a sticky secre- 

 tion which enables those laid on the host to adhere. Hatching occurs 

 in 6-1 1 days at 90-95° F., and in 9-1 1 days at 80° F. The newly 

 hatched larva starts to feed immediately on the cockroach. Larval 

 stage lasts 4-6 days, rests 2-3 days, and molts. During the single 

 nymphal instar, the mite feeds on the host and moves about for 6-7 

 days. The mite then rests 3-4 days before molting. Entire life cycle 

 covers a period of 28-32 days. Adult mite lives 2-3 weeks, during 

 which time it can produce 2-3 batches of from i to 20 eggs ; the usual 

 batch is about 12 eggs. The mites are unable to live on cockroach 

 feces, cast skins, or dead cockroaches. Mites died within 4-5 days 



