BIOTIC ASSOCIATIONS OF COCKROACHES — ROTH & WILLIS 1 5 



roaches with long ovipositors may have inserted their eggs singly 

 into trees and other plants, rather than protecting the eggs with an 

 ootheca. However, Laurentiaux (1951), although conceding the 

 possibility of egg laying in vegetable material, suggested that ovi- 

 position into the earth is more probable because of the unbending 

 nature of the ovipositor. 



Although the ecological associations of modern cockroaches should 

 be well known from direct observation, actually most species are still 

 little more than names on museum specimens, and our knowledge of 

 them is fragmentary. All too frequently ecological observations have 

 been only incidental to taxonomic or faunistic studies; yet the bio- 

 logical information that is contained in such papers is all that we know 

 of many species. For this reason we have cited these observations in 

 some detail, especially when they were brief; longer accounts of cock- 

 roach bionomics, of necessity, have been abstracted. 



Very few exclusively ecological studies of insects have included 

 cockroaches. The native woodroaches (Parcoblatta pensylvanica, P. 

 uhleriana, and P. wrginica) of the northern United States were in- 

 cluded in ecological studies of the Orthoptera by Hubbell (1922), 

 Strohecker (1937), and Cantrall (1943). Fifteen species of cock- 

 roaches were included in an ecological study of the Orthoptera of 

 northern Florida by Friauf (1953). The original papers should be 

 consulted for detailed descriptions of the habitats and accounts of the 

 associated plants and other Orthoptera. 



In this chapter the cockroaches are grouped into those that have 

 been found in man-made structures and those that occur in other 

 habitats. Certain species may appear in several categories because 

 they live both indoors and out. The structural pests are divided into 

 cockroaches that occur in land-based structures, those on ships, and 

 those in aircraft. The nonstructural cockroaches are divided into 

 those that occur in quite specific habitats (caves, water, and deserts) 

 and those that occur generally out of doors. Nests of various arthro- 

 pods serve as microhabitats of commensal cockroaches; these latter 

 associations are discussed on pages 310-318. 



In this chapter our discussion is limited to the physical environment 

 and specific habitats of cockroaches, and only very general references 

 are made to associated organisms. The relationships of cockroaches 

 to the biota are examined in detail in subsequent chapters. To show 

 the full extent of the associations, the associates, from bacteroids to 

 vertebrates, are arranged phyletically. These associate-centered clas- 

 sifications serve admirably to relate various species of cockroaches 

 within common bounds, but fail to give an integrated account of the 



