A 98-million-year-old praying mantis discovered in Myanmar amber shows the earliest fossil evidence of insects mimicking plant leaves, researchers said.
The specimen is named Folimantis hyalinala. Its abdomen closely resembles the extinct plant Selaginella grimaldii. This discovery appeared in the journal New Phytologist and suggests plant mimicry has been part of the mantids’ evolutionary toolkit for at least 98 million years.
The genus name Folimantis translates to ‘leaf mantis’. The species name hyalinala describes the glass-like transparency in the wings.
Researchers said insect-plant mimicry has likely evolved for at least 200 million years. But finding reliable fossil examples is difficult.
“Though the mimicry relationship between insects and plants has evolved over at least 200 million years, reliable fossil examples of insect-plant mimicry are scarce,” paleoentomologist Hongru Yang and colleagues wrote.
“The mimicry style of F. hyalinala with Selaginella has never been reported before, and there are no species that mimic Selaginella among modern Mantodea,” researchers wrote in the New Phytologist paper.
The mantis lived in a tropical rainforest during the mid-Cretaceous period. Flowering plants had not yet taken over the environment at that time, so its body evolved over generations to look like leaves instead. According to evolutionary theory, mantises that gained an advantage by appearing more like plants survived better. These insects could transmit their genes to the next generation.
A mantis with a closer resemblance to its host plant could ambush prey. It could also remain better hidden from its own predators.
The plants benefitted too. The mantid inhabitants protected them from herbivorous insects.
This specimen shows that plant mimicry has existed in mantids for at least 98 million years. Praying mantises share an ancestor with cockroaches from around 274 million years ago.
Scientists suggested that distinct mantises first appeared approximately 185 million years ago. This occurred during the Jurassic period while the supercontinent Gondwana was breaking up.
Kachin amber mining and trade is linked to sociopolitical turmoil in Myanmar. This discovery occurs as people scrutinize amber extraction in the region.
Worries exist that the amber trade provides funds for what the United Nations condemns as a “genocidal crime against humanity”.
Myanmar prohibited the exportation of fossils in 2015. However, specimens encased in amber have entered a legal grey area.
The Society of Vertebrate Paleontology issued a directive regarding the ethics of such finds after a military coup in 2021.
The organization called for a “hard moratorium on the publication of all fossil specimens in amber obtained from sources in Myanmar after January 2021”, according to ScienceAlert.