Scientists believe that insects carrying eggs on their bodies may indicate an adaptation to ecological environments or a response to changes in ancient ecosystem dynamics.
Chinese researchers have discovered the oldest evidence of the instinct for egg protection in insects.
Water beetle species. (Illustrative image: Flickr)
The research report published in the Proceedings of the Royal Society B on July 18 shows that insects have been caring for their eggs since the transition between the Middle Jurassic and Late Jurassic periods, over 161 million years ago, rather than just 38 million years as previous studies concluded.
Care for offspring “from the egg stage” is an important adaptive behavior related to parental protection and care for successive generations. This skill has evolved independently multiple times in various animal species, including mammals, birds, dinosaurs, arthropods, and especially insects.
Researchers at the Nanjing Institute of Geology and Palaeontology, part of the Chinese Academy of Sciences, analyzed fossil samples from the population of Karataviella popovi – a water beetle species that existed 160 million years ago.
These fossils show that female Karataviella popovi carried many egg sacs on their left legs. Detailed imaging analysis of one female Karataviella popovi revealed up to 30 fossilized eggs arranged in 5 to 6 rows, with each row measuring between 1.14 to 1.2 mm in length.
According to the study, Karataviella popovi carries eggs on its legs to physically protect them while effectively preventing oxygen deprivation during the incubation period. This behavior of mother Karataviella popovi is considered crucial for the development and reproduction of the eggs; however, it also increases the risk of predation for the mother water beetle.
