Crevice Fauna

The cockroaches considered crevice fauna are those that insert themselves into preexisting small voids in generally unyielding substrates. These include species found under bark, in bark fissures, in the bases of palm fronds and grass tussocks, in hanging dead leaves, empty cocoons, and hollow twigs, under logs and rocks, in piles of stones, rock crevices, and the excavated galleries of other insects. An example of the latter is the Malaysian cockroach Mar-gattea kovaci, which lives in bamboo internodes accessed via holes excavated by boring Coleoptera and Lepi-doptera (D. Kovach, pers. comm. to LMR). Burrowing and crevice-dwelling cockroaches can be categorically difficult to separate, particularly species that shelter under rotting logs, in rolled leaves, or in the litter wedged into the base of bunch grasses, spinifex, or the leaf axils of many plants. The spaces under rocks and stones are a particularly important microhabitat for cockroaches in un-

forested areas. Species of the genera Deropeltis and Pseu-doderopeltis, for example, are abundant under the boulders "bestrewing the Masai steppe country" (Shelford, 1910b). Rock-soil interfaces may also act as corridors between habitats, serving as oases for cockroaches moving between caves, or between patches of forest (Lawrence, 1953). Some cockroach species are morphologically specialized to inhabit the wafer-thin crevices under bark or rocks (Fig. 1.10). The incredibly flattened bodies of tropical Australian Mediastinia spp. allow them to slip into the unfolding leaves of gingers, lilies, and similar plants during the day. At night they move to new quarters as the leaves of their previous shelters unfold (D. Rentz, pers. comm. to CAN).

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