A new study led by a team of paleobiologists from the University of Leicester has found that not all grasshoppers are herbivorous, as scientists initially thought. By identifying startling similarities between the mouths of some species of grasshopper and mammal teeth, the researchers have shown that many of the 11,000 known species of grasshopper may even be carnivorous.
Finding out what grasshoppers eat usually requires detailed investigations of the contents of their guts or painstaking, time-consuming observations of what they feed upon in the wild.
“Knowing what animals eat is fundamental to understanding ecosystems, but working this out can be difficult and time consuming, especially if the animals you study are rare, small, or move quickly,” said study lead author Christopher Stockey, a postgraduate researcher at the University of Leicester.
However, Stockey and his colleagues have found a better, faster, and less invasive method of discovering more about grasshoppers’ diets: they used sophisticated three-dimensional imaging techniques to precisely map the shape of the mandibles of museum grasshopper specimens and to compare them with mammals’ teeth.
“One of the advantages of our method is the powerful comparisons that it provides,” said Stockey. “Surprisingly, comparing the mandible landscapes of grasshoppers with mammal’s teeth allows grasshopper diet to be predicted with 82 percent accuracy – pretty amazing when you consider that the mouthparts of mammals and grasshoppers have evolved independently for 400 million years, and were not present in their common ancestor.”
These measurements revealed clear differences linked to diet between various species of grasshopper. “Mandibles from carnivorous grasshoppers that eat soft flesh have steeper slopes and sharper cliff edges, while those that eat tough plant material, such as grass, have mandibles with complex undulating ‘landscapes,’” explained Stockey.
“This study is a great example of combining modern analytical methods with historical samples from museum collections to help understand the biodiversity of our planet,” said Dr. Ben Price, a senior curator at the Natural History Museum. “As technology advances additional uses of museum collections become possible and this non-destructive approach could reveal the diet information for thousands of species, decades after the specimens were collected.”
The study is published in the journal Methods in Ecology and Evolution.
By Andrei Ionescu, Earth.com Staff Writer