title: Debris-carrying camouflage among diverse lineages of Cretaceous insects.
abstract: Insects have evolved diverse methods of camouflage that have played an important role in their evolutionary success. Debris-carrying, a behavior of actively harvesting and carrying exogenous materials, is among the most fascinating and complex behaviors because it requires not only an ability to recognize, collect, and carry materials but also evolutionary adaptations in related morphological characteristics. However, the fossil record of such behavior is extremely scarce, and only a single Mesozoic example from Spanish amber has been recorded; therefore, little is known about the early evolution of this complicated behavior and its underlying anatomy. We report a diverse insect assemblage of exceptionally preserved debris carriers from Cretaceous Burmese, French, and Lebanese ambers, including the earliest known chrysopoid larvae (green lacewings), myrmeleontoid larvae (split-footed lacewings and owlflies), and reduviids (assassin bugs). These ancient insects used a variety of debris material, including insect exoskeletons, sand grains, soil dust, leaf trichomes of gleicheniacean ferns, wood fibers, and other vegetal debris. They convergently evolved their debris-carrying behavior through multiple pathways, which expressed a high degree of evolutionary plasticity. We demonstrate that the behavioral repertoire, which is associated with considerable morphological adaptations, was already widespread among insects by at least the Mid-Cretaceous. Together with the previously known Spanish specimen, these fossils are the oldest direct evidence of camouflaging behavior in the fossil record. Our findings provide a novel insight into early evolution of camouflage in insects and ancient ecological associations among plants and insects.
authors.affiliation: State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China.; Steinmann Institute, University of Bonn, 53115 Bonn, Germany.; Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.affiliation: Nanjiao Bieshu 394, Shanghai 201108, China.
authors.forename: Fangyuan
authors.initials: F
authors.lastname: Xia
authors.affiliation: Division of Entomology, Natural History Museum and Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Engel
authors.affiliation: CNRS UMR 6118 Géosciences and OSUR, Université de Rennes 1, 35042 Rennes, France.
authors.forename: Vincent
authors.identifier: 0000-0002-7973-0430
authors.initials: V
authors.lastname: Perrichot
authors.affiliation: State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Gongle
authors.identifier: 0000-0003-3374-6637
authors.initials: G
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China.
authors.forename: Haichun
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China.; Institute of Geology and Paleontology, Linyi University, Linyi 276000, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China.; Department of Earth Sciences, Natural History Museum, London SW7 5BD, UK.
authors.forename: Edmund A
authors.initials: EA
authors.lastname: Jarzembowski
authors.affiliation: Steinmann Institute, University of Bonn, 53115 Bonn, Germany.
authors.forename: Torsten
authors.identifier: 0000-0003-1592-0988
authors.initials: T
authors.lastname: Wappler
authors.affiliation: Steinmann Institute, University of Bonn, 53115 Bonn, Germany.
authors.forename: Jes
authors.identifier: 0000-0001-6970-3490
authors.initials: J
authors.lastname: Rust
mesh_terms: D000222:Adaptation, Physiological; D018647:Amber; D000818:Animals; D001522:Behavior, Animal; D005075:Biological Evolution; D000067558:Biological Mimicry; D005580:Fossils; D007313:Insecta; D007814:Larva; D010163:Paleontology
chemical_list: D018647:Amber
keywords: Cretaceous; camouflage; paleobotany; paleoecology; paleoentomology