A brief review of the fossil history of plant masquerade by insects
published: Oct 4, 2010
Defensive strategies of insects against visual hunting predators include crypsis, aposematism, and mimicry. In the extant fauna, many cryptic insects mimic leaves or twigs; these include several groups of grasshoppers and katydids (Orthoptera), stick and leaf insects (Phasmatodea), praying mantises (Mantodea), and moths and butterflies (Lepidoptera). Their masquerade is not only perfected by many morphological adaptations but also by specialised behaviour. Reliable records of plant masquerade by fossil insects are lacking from the Palaeozoic and early Mesozoic. The oldest definitive fossil record of stick mimicking in Orthoptera (Orthoptera: Proscopiidae) comes from the Early Cretaceous Crato Formation, Brazil, while the first records of stick mimesis in Phasmatodea are from Eocene Baltic amber and the Eocene Messel pit in Germany. The oldest fossil record of leaf mimicking was found in a phasmid insect (Phasmatodea: Phylliinae) from the Eocene of Messel. Several species of advanced leaf-mimicking katydids (Orthoptera: Tettigoniidae: Pseudophyllinae) are recorded from the late Eocene-early Oligocene of France and England. All in all, fossil records of plant mimicking by insects are still quite scarce, but recently discovered fossils show that there is much waiting to be discovered.