330 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I4I 



mostly in colonies made up of mothers and their young. The duration 

 of these associations is not known. 



Saupe (1928) noticed that the newly hatched nymphs of Blaberus 

 craniifer (see footnote 11, p. 322) collected together under the body 

 of their mother and stated that this is as pronounced a case of brood 

 care as Zacher had observed with Pycnosceliis surinamensis. Nutting 

 (1953) stated that "A degree of maternal solicitude is exhibited by 

 this roach [5. craniifer], for many times I have observed the female 

 to remain motionless for an hour or more with her unpigmented 

 brood clustered around and beneath her body." We, too, have ob- 

 served similar behavior in laboratory colonies of J5. craniifer and 

 Leitcophaea maderae. 



Chopard (1950) noted that after hatching the young of Grompha- 

 dorhina laevigata remained grouped around the female for some time ; 

 the mother stood motionless, high on her legs, with her thorax curved 

 up to make room for the brood which hid under her body. We (unpub- 

 lished data, 1958) have seen young nymphs of Gromphadorhina por- 

 tcntosa also stay near their mother for some time after birth; the 

 mother at this time produced a characteristic hissing sound when she 

 was only slightly disturbed by the movement of our hand near her and 

 her brood. The sound is produced as air is expelled through the second 

 abdominal spiracle. We have seen recently hatched nymphs of Nau- 

 phoeta cinerea crawl beneath the mother, even under her wings, where 

 they remained about an hour (WiUis et al., 1958). Bunting (1956) 

 observed a female of Blaberus discoidalis collect a mound of debris 

 into which she inserted the tip of her abdomen ; he found young in 

 the mound later the same day. This female showed no maternal care 

 for the young after birth. Whole families of cockroaches may be 

 found in bromeliads in Brazil (Ohaus, 1900). Hebard (1920) ob- 

 served a colony of adults and young of Dendrohlatta sobrina on a 

 tree trunk in the Panama Canal Zone. 



Whether any of the above associations exemplify maternal care for 

 the newly hatched young is questionable. The behavior of the mother, 

 beyond placing her eggs in a suitable location, seems to be entirely 

 passive. The first-instar nymphs are the active partners in these 

 associations, and they may merely be seeking shelter under the nearest 

 convenient object rather than under the mother as such. More exten- 

 sive studies of some of these relationships will be needed before claims 

 for maternal care, as suggested by Scott ( 1929) , can be substantiated. 



GREGARIOUSNESS 



Casual statements that cockroaches are gregarious are often en- 

 countered in the literature. There has been some argument to the 



