Bizarre-looking insects used clutter as camouflage
Amber-trapped insects show that several carnivorous species have been cloaking themselves in clutter for more than 100 million years.
Dead insect prey, parts of plants, and grains of sand and soil were all hoarded to disguise their look and perhaps smell from their prey.
The earliest-known examples of this complex camouflage behaviour have been found by scientists at Nanjing Institute of Geology and Palaeontology and the Natural History Museum, London. They combed through 300,000 amber-trapped specimens from 90 to 130 million years ago to find 35 examples of the behaviour.
In addition to making hunting easier, the camouflage helped mask the insects from their own predators and offered a protective shield if attacked. The insects' modern descendants still use the same techniques today, yet no living species have the bizarre, extremely long tubules seen in the fossilised lacewings.
Professor Edmund Jarzembowski, an associate scientist at the Natural History Museum who worked on the specimens commented: 'The real surprise it that completely unrelated groups, the lacewings and the assassin bugs, had both already adapted this camouflage technique. This is an example of convergent evolution – they must have both been under the same selection pressures which made this type of behaviour a successful strategy.'
Like their modern counterparts, only the immature insects display this behaviour, as adult insects would find it hard to fly carrying extra material. Immature insects are rarely found as fossils, as they are less mobile and therefore less likely to get stuck somewhere suitable for fossilisation.
Nearly all the specimens were found in 100 million year-old Burmese amber, from northern Myanmar. This high quality, clear amber is now easier to access and is proving a treasure trove for Cretaceous fossil finds.
This study was part of the Museum’s research programme to understand the origins and diversity of life and the delicate balance of ecosystems, to better predict the impact of future environmental change.
Notes for editors
Original publication and extra files including images (Images © Bo Wang)
B. Wang, F. Xia, M. S. Engel, V. Perrichot, G. Shi, H. Zhang, J. Chen, E. A. Jarzembowski, T. Wappler, J. Rust, Debris-carrying camouflage among diverse lineages of Cretaceous insects. Sci. Adv. 2, e1501918 (2016). http://advances.sciencemag.org/content/2/6/e1501918
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