text | "China Science News" reporter Shen Chunlei
Insects have maternal love, and their adaptive behavior of maternal care can be traced back to at least the Middle Jurassic.
This discovery was proved by the team of Huang Diying, researcher at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences.
They advance direct evidence of insect nursery behavior by nearly 40 million years.
html On July 13, relevant research results were published online in the British "Proceedings of the Royal Society, Series B".
Ecological recovery map of the Cara stink bug, painted by Sun Jie
Parental care is an important adaptive behavior, which refers to the protection, care and feeding of eggs or offspring by parents, etc., in mammals, birds, reptiles, arthropods , especially among social insects, which evolved independently many times.
Egg-carrying behavior is a form of parental care. It is usually the behavior of a single parent to carry eggs or larvae after laying eggs to provide protection, which can effectively improve the hatching rate and offspring survival rate.
Huang Diying's team conducted a systematic study on the fossils of Caracana in the Daohugou Biota of the Middle and Late Jurassic. They identified 30 egg-carrying female adult fossils among 157 fossils of Caracana and conducted functional morphology on them. Comprehensive analysis reveals the unique egg-carrying behavior of stink bugs in the Middle and Late Jurassic.
Huang Diying introduced that on the left tibia of some female individuals of the Calla stink bug, about 5 to 6 rows of closely arranged eggs, each row with about 6 to 7 eggs with a length of 1.14 mm to 1.20 mm, are attached to the tibia by the egg stalk. festival.
The left tibia of the female egg-carrying individual is thicker than the right tibia and that of the male.
Researchers speculate that the predation risk and periodic food sources caused by the large number of salamanders in the Daohugou biota have put the Kala's stink bug under great ecological pressure. The egg-carrying behavior may reflect the Kala's stink bug's impact on the habitat ecology. Environmental adaptation or response to changes in ancient lake ecosystems.
Huang Diying said: "The egg-carrying behavior of the Kala stink bug can provide physical protection for the eggs during the incubation process and effectively prevent the eggs from drying and hypoxia, which is of great significance to their evolution and reproduction. However, this kind of selfless maternal protective behavior There may be higher costs, such as increased risk of predation."
He also pointed out that the egg-carrying strategy has not been found in other living and extinct insect groups, but it is not found in aquatic arthropods. It is rare, and its fossil record can be traced back to the Chengjiang biota in the early Cambrian period.
However, the behavior of carrying eggs with one foot is an isolated case.
This study highlights the diverse and little-known nursery strategies of Mesozoic insects and helps to understand the evolutionary and adaptive significance of insect nursery behavior.
related paper information:
https://doi.org/10.1098/rspb.2022.0447
