BIOTIC ASSOCIATIONS OF COCKROACHES — ROTH & WILLIS 35 



The above list does not exhaust the available outdoor microhabitats 

 that cockroaches find suitable for their continued existence, but it is 

 fairly representative. Although we have no measurements to substan- 

 tiate this conclusion, we suggest that the microhabitats cited above 

 have a more constant temperature and a relatively higher humidity 

 than is provided by the surrounding macrohabitats. We would ex- 

 pect insects such as cockroaches, whose water balance is dependent 

 on a continuous supply of fluid water or moist food, to seek moist 

 environments or to avoid situations in which their transpiration might 

 increase. Deviations, presumably brief, from this expected behavior 

 must occur to account for the cockroaches that are found under rela- 

 tively unfavorable environmental conditions. Despite the apparent 

 preference for cryptic habitats, some cockroaches are found in hot 

 sunlight (Ellipsidion spp. ; Tepper, 1893); Rehn (1945) has stated 

 that many kinds are diurnal rather than nocturnal. Movement of 

 cockroaches between habitats may be assumed to occur; but move- 

 ment from an unfavorable environment to a more favorable one, 

 following a shift in water balance, has not been observed in nature ; 

 however, laboratory experiments suggest that the mechanism for 

 mediating such behavior is present in some species of cockroaches 

 (Gunn and Cosway, 1938; Roth and Willis, 1952a). Obviously, addi- 

 tional research is needed on the bionomics of all species. Further con- 

 clusions based on current limited knowledge can only be speculative 

 and possibly misleading. 



COCKROACHES FROM OUTDOOR HABITATS 



(Except Amphibious, Desert, and Cavernicolous Forms) 



Aglaopteryx absimilis 



Puerto Rico. — Living in rotten, wooden fence ; living between 

 leaves of Samanea saman and in abandoned cocoons of Megalopyge 

 krugii on bucare trees (Wolcott, 1950). 



Leeward Islands. — On coconut tree (Princis and Kevan, 1955). 



Aglaopteryx fades 



Puerto Rico. — As diaphana, in dead branch 10 feet above the 

 ground on Mona Island (Hebard, 1917). In trunks of trees under 

 bark and very often in abandoned cocoons of the "plumilla" (Sein, 

 1923). On rotten, wooden fence; in empty cocoons of Megalopyge 

 krugii on trunks of bucare trees, Erythrina glauca; on trunk of Inga 

 laurina; in larval tents of Tetralopha scabridclla on Inga vera (Wol- 

 cott, 1936). In large numbers in nests of the gray kingbird (Wolcott, 

 1950)- 



