The most famous of the insect fakes is sometimes called “Piltdown” Fly, a reference to a famous human skull fake. Piltdown fly was in a piece of 38 million year old amber that was collected by the London Museum of Natural History. This specimen attracted the attention of renowned systematist, Willi Hennig. Hennig could detect no sign of fakery. The fly was indistinguishable from the latrine fly, Fannia scalaris. Hennig wrote a paper using the fake as an example of how little this fly had changed over time. The fake was good enough to fool many experts.
30 years later, another scientist was studying the specimen when it cracked under the heat of a microscope light. It then became apparent that someone had hollowed a chamber in the piece of amber, inserted the filth fly, then covered the hole and fly with resin.