Caves

As discussed in the following chapter, caves are at one end of a continuum of subterranean spaces frequented by cockroaches, with the border between caves and other such habitats often vague. Variation in wing reduction, as well as associated morphological changes, may reflect different degrees of adaptation to these specialized habitats. In Australian Paratemnopteryx, species found in caves usually exhibit some degree of wing reduction (Table 2.2). Several species in this genus are intraspecifically variable; both macropterous and reduced-wing morphs of Para. howarthi can even be found in the same cave (Roth, 1990b). Epigean species in the genus living under bark or in leaf litter are often macropterous, but also may exhibit wing reduction. The area of the cave inhabited (deep cave versus twilight zone), nutrient availability (is there a source of vertebrate excrement?), and length of time a population has been in residence all potentially influence the morphological profiles of the cave dwellers. Like other invertebrates, cockroaches that are obligate cavernicoles (troglobites) typically exhibit wing reduction or loss.

Table 2.2. Wing development in cavernicolous and epigean species of the Australian genus Paratemnopteryx, based on Roth (1990b), Roach and Rentz (1998),and Slaney (2001). Those species described as epigean were found under bark and in litter.

Species

Habitat

Wing condition

Para. atra

Cavernicolous, in mines

Slightly reduced

Para. australis

Epigean, one record from termite nest

Reduced

Para. broomehillensis

Epigean

Macropterous

Para. centralis

Epigean

Macropterous

Para. couloniana

Epigean, in houses

Variably reduced, some males macropterous

Para. glauerti

Epigean

Male macropterus, female reduced

Para. howarthi1

Cavernicolous

Macropterous and

and epigean

reduced males, females reduced

Para. kookabinnensis

Cavernicolous

Reduced

Para. rosensis

Epigean

Male macropterous, female reduced

Para. rufa

Cavernicolous and epigean

Reduced

Para. stonei

Cavernicolous and epigean

Variably reduced2

Para. suffuscula

Epigean

Macropterous

Para. weinsteini

Cavernicolous

Reduced, female more so

1Brachypterous and macropterous morphs can be found in same cave. 2Female wings slightly longer than male's.

1Brachypterous and macropterous morphs can be found in same cave. 2Female wings slightly longer than male's.

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