Researchers discover earliest brood care in insects

BEIJING, July 18 (Xinhua) -- Chinese researchers have traced the earliest brood care among insects dating back to the Middle-Late Jurassic period, according to a recent research article published in the journal Proceedings of the Royal Society B.

The founding pushed back the evidence of insect brood care by more than 38 million years, the China Science Daily reported.

Brood care is an important adaptive behavior referring to parental protection, care, and feeding of eggs or offspring. It has evolved independently multiple times in animals such as mammals, birds, dinosaurs, and arthropods, especially various lineages of insects.

The researchers from the Nanjing Institute of Geology and Palaeontology under the Chinese Academy of Sciences analyzed the biota of Karataviella popovi with adult females bearing clutches of eggs on their left mesotibia.

The 30 fossilized eggs appeared in five to six rows, each measuring a length of 1.14 to 1.2 millimeters.

Karataviella popovi bore eggs to provide physical protection and effectively prevent dryness and hypoxia during hatching, according to the report. The unselfish maternal behavior was crucial for the evolution and breeding of the eggs while increasing the predation risk for the adult female insects.

Bearing eggs might reflect the insects' adaptation to the ecological environment of the habitat or their response to the changes in the ancient lake ecosystem.

The breeding strategy of bearing eggs with the foot has not been discovered among other existing and extinct insects, but it is common in aquatic arthropods, noted the report.