BIOTIC ASSOCIATIONS OF COCKROACHES — ROTH & WILLIS 333 



mained almost constantly in groups during the first and second instars, 

 but less SO during the third instar. He believed that the aggregations 

 of young occurred because they could occupy narrow crevices where 

 the larger insects could not penetrate. At usual room temperatures the 

 older nymphs and adults lived completely isolated, but at certain 

 temperatures they gathered together in large, tightly pressed groups. 



Supella siipellectilkmi is said to be gregarious (Gould and Deay, 

 1940). The smaller nymphs aggregate in small groups in rearing 

 containers, but the older ones remain separate from one another 

 (Hafez and Afifi, 1956). Leucophaea maderae is sociable and rarely 

 found alone ; in their favorite hiding places, hills of these cockroaches 

 can be seen hanging together (Sein, 1923). Wolcott (1950) also 

 stated that L. maderae is gregarious. Annandale (1900) observed that 

 in the "Siamese Malay States" large colonies of Periplaneta australa- 

 siae conceal themselves in hollows of bamboo logs from which houses 

 are built. Moulton (1912) stated that he was astonished at the large 

 numbers of F. australasiae and Syniploce cavernicola that he saw 

 swarming on the sides of caves of Mt. Jibong, Borneo. 



Rehn and Hebard (1905) stated that in Key West, Fla., Eurycotis 

 fioridana fairly swarmed under the coquina boulders in the woods, in 

 groups of a dozen containing both young and adults ; Pycnoscelus 

 surinamensis was very abundant in the same type of habitat. Caudell 

 (1905) also found the young of E. fioridana with the mature in- 

 dividuals. Hebard (1917) in his discussion of Lattiblattella rehni 

 again mentioned finding frequent colonies of E. floridatm in Florida. 

 He also found many specimens of Blaberus craniifer under boards on 

 the ground at Key West. He found Parcoblatta lata numerous under 

 bark of dead pine trees in Alabama. However, Dowdy (1955), in an 

 ecological study of oak-hickory forest in Missouri, stated that ''Par- 

 coblatta [sp.] were never recorded as being gregarious, in fact they 

 were mostly solitary. However, in some cases two were found to- 

 gether," Yet Blatchley (1895) stated of Parcoblatta pensylvanica 

 that in the winter in Indiana "One cannot pull the loose bark from an 

 old log without dislodging a colony of from ten to a hundred of the 

 nymphs of various sizes." Males of Parcoblatta virginica were said 

 to be often gregarious beneath loose bark and under chunks and rub- 

 bish (Blatchley, 1920). 



Rehn and Hebard (1927) quoted observations made earlier by He- 

 bard on Byrsotria fumigata in Cuba : "I found the specimens under flat 

 stones, sometimes in colonies of 3 or 4 mature specimens and numbers 

 of immature individuals in all stages of development." These ob- 

 servers also reported that Aspiduchns borinquen was found in Puerto 



