The Pancake Syndrome

The dorsoventrally compressed morphotype typical of the "classic" cockroach has been taken to extremes in several distantly related taxa. These extraordinarily flattened insects resemble limpets and live in deep, narrow clefts such as those found under loose bark, at the log-soil in terface, under stones, or in the cracks of boulders and rocks. In most species, the borders of the tergites are extended, flattened, and held flush with the substrate so that a close seal is formed (Fig. 1.10). The proximal parts of the femora may be distinctively flattened as part of the overall pancake syndrome (Mackerras, 1967b; Roth, 1992). Included in this group are female West Indian Homalopteryx laminata (Epilamprinae) (Kevan, 1962) and several Australian taxa. A number of Leptozosteria and Platyzosteria spp. (Polyzosteriinae) live in deep, narrow clefts under rocks or bark (Mackerras, 1967b; Roach and Rentz, 1998). Members of the genus Laxta (Epilam-prinae) live under eucalypt bark and are common under large slabs at the bases of trees (Roth, 1992; Rentz, 1996). Some Central and South American Zetoborinae (e.g., Lanxoblatta emarginata, Capucina patula) and Blaberi-nae (e.g., Mon. biguttata nymphs) have a comparable body type and habitat (Roth, 1992; Grandcolas and Dele-porte, 1994; Pellens and Grandcolas, 2003; WJB, unpubl. obs.). Highly compressed morphotypes are associated

Fig. 1.10 (A) Ventral view of head and expanded pronotum and metanotum of an unidentified, dorsoventrally flattened cockroach collected under bark in Brazil; most likely a female or nymph of Capucina patula or Phortioeca phoraspoides (LMR, pers. obs.). Note debris attached to the pronotal edges, which were closely applied to the wood surface. Photo courtesy of Edward S. Ross. (B) Female of Laxta friedmani (named after LMR's urologist). Photo courtesy of David Rentz.

Fig. 1.10 (A) Ventral view of head and expanded pronotum and metanotum of an unidentified, dorsoventrally flattened cockroach collected under bark in Brazil; most likely a female or nymph of Capucina patula or Phortioeca phoraspoides (LMR, pers. obs.). Note debris attached to the pronotal edges, which were closely applied to the wood surface. Photo courtesy of Edward S. Ross. (B) Female of Laxta friedmani (named after LMR's urologist). Photo courtesy of David Rentz.

Fig. 1.11 Mechanisms of cockroach defense against ants. (A) Chemical defense by Diploptera punctata. Pogonomyrmex badius is attacking the cockroach on the left, whose defensive glands have been removed. The intact cockroach on the right was also attacked by the ants, but it discharged a spray of quinones and repelled the attackers. The spray pattern is shown by indicator paper on which the cockroach is standing. From Eisner (1958). (B) Defense by conglobulation. Adult female of Perisphaerus semilunatus from Thailand, protected from attack by rolling up into a ball. From Roth (1981b). (C) Defense by adhesion. A flattened Capucina patula nymph protected from attack by hugging the substrate. The body of the cockroach is clearly seen through the lateral extensions of the tergites. All photographs courtesy of Thomas Eisner.

Fig. 1.11 Mechanisms of cockroach defense against ants. (A) Chemical defense by Diploptera punctata. Pogonomyrmex badius is attacking the cockroach on the left, whose defensive glands have been removed. The intact cockroach on the right was also attacked by the ants, but it discharged a spray of quinones and repelled the attackers. The spray pattern is shown by indicator paper on which the cockroach is standing. From Eisner (1958). (B) Defense by conglobulation. Adult female of Perisphaerus semilunatus from Thailand, protected from attack by rolling up into a ball. From Roth (1981b). (C) Defense by adhesion. A flattened Capucina patula nymph protected from attack by hugging the substrate. The body of the cockroach is clearly seen through the lateral extensions of the tergites. All photographs courtesy of Thomas Eisner.

with defense against both abiotic and biotic hazards. In the intensely arid climate of Australia, these cockroaches squeeze into deep, narrow clefts and cracks to avoid desiccation (Mackerras, 1967b). In the Neotropical species, it has been demonstrated that compressed bodies confer protection against ant attacks (Fig. 1.11C). The insects become immobile and cling so tightly to the substrate that their vulnerable undersurfaces cannot be harmed (Grandcolas and Deleporte, 1994; Pellens and Grandco-las, 2003; Roth, 2003a).

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