Cockroache; Ecology, behavior & history - W.J. Bell

Fig. 3.1 Occupation of different habitats by cockroaches in a reserve near the town of Welaka
in northeastern Florida. Of the habitats examined, only four contained no cockroaches: ponds,
lawns, and dry and moist sparsely vegetated sand. Based on information in Friauf (1953).
HABITAT SPECIFICITY
Sorting out habitat specificity in a secretive taxon like
cockroaches is a daunting task. Although some species are
known to be habitat specific and have associated morphological,
physiological, behavioral, and life history
modifications, many are much more flexible in their living
conditions. Of 19 examined habitats that contained
cockroaches in a reserve in northeastern Florida, Parcoblatta
virginica, Parc. lata, and Arenivaga floridensis were
each found in just one habitat, and five cockroach species
were found only in structures (Fig. 3.1) (Friauf, 1953).
Cariblatta lutea, on the other hand, was found in 15 of
the habitats, and nymphs of this species have also been
recorded from the burrows of small vertebrates (Hubbell
and Goff, 1939). In Jamaica Car. lutea is found in leaf litter,
under debris of every kind, in dead agaves, and in
bromeliads (Hebard, 1916a). Even closely related cockroaches
may vary widely in habitat choice (Table 3.1),
making the detection of phylogenetic trends problematic.
ONTOGENY OF HABITAT USE
Although nymphs generally live in the same habitats as
adults (Mackerras, 1970), there are several cockroach
species that exhibit ontogenetic niche shifts. The most
common pattern is that of females, female-nymph combinations,
and groups of young nymphs reported from
burrows, shelters, and other protected sites, often in or
near a food source. These sheltered sites serve as nurseries,
with the habitat of youngest nymphs determined
by the partition 3 behavior of the mother; subsequently,
nymphs may or may not disperse from their natal area. In
all species of Gyna, for example, adults are found primarily
in the canopy, while nymphs are found at ground
level, often burrowing in the dust of treeholes, abandoned
insect nests, and caves (Corbet, 1961; Grandcolas, 1997a).
Juveniles of Capucina patula are restricted to the habitat
beneath loose bark of live or fallen trees; adults are occasionally
seen on nearby foliage (WJB, pers. obs.). Nymphs
of Car. lutea, and females and nymphs of Parcoblatta fulvescens
have been recorded from the burrows of pocket
gophers (Geomys sp.) (Hubbell and Goff, 1939). Adults of
both these species are found in a variety of above-ground
habitats. Adults of Parcoblatta bolliana are found in grass-
3. Partition is defined as the expulsion by the female of the reproductive
product, whether it is an egg or a neonate (Blackburn,
1999).
38 COCKROACHES