[Smart Farmers] Subvert the impression! This kind of "working" bees can also reproduce offspring

Recently, the Pollinator Reproduction and Pollination Application Innovation Team of the Bee Research Institute of the Chinese Academy of Agricultural Sciences, in collaboration with domestic and foreign universities and enterprises, found that bumblebee workers do not stagnate throughout their lives. This study challenges the law that "superorganic worker bees cannot mate for life before they emerge from the womb", and reveals an ancient mystery of the superorganic bumblebee caste evolution. This is a major leap forward in understanding the evolution of superorganisms. The relevant research results were published in Nature Communications.

Superorganism bumblebees belong to the intermediate differentiation group of social insects. One of the main evolutionary laws is that the queen bee determined by the pre-emergence type is destined to mate, while the worker bees never mate. The worker bees of superorganisms such as honey bees and ants have lost or only retained the degenerate spermathecae structure. However, although the superorganism bumblebees have evolved for 25 million to 40 million years, the worker bees still retain the complete spermathecae but cannot mate for life, which has become an unsolved mystery in academia for a long time.

Uncovering the mystery of bumblebee evolution: Worker bees can mate, give birth to female offspring, and reproduce bee colonies

To this end, the research team first verified through artificial insemination technology that the spermatheca of bumblebee workers still has reproductive functions such as storing sperm, releasing sperm, and promoting egg fertilization, and verified through transcriptome that their gene expression patterns before and after fertilization are similar to those of queen bees. Bumblebee workers retain reproductive characteristics similar to those of queen bees and are able to mate and create bee colonies. Secondly, the study found that isolated bumblebee workers after emergence are capable of mating, which means that the mating ability of worker bees is not lost before emergence, but is lost only after being inhibited by social factors in the bee colony. At the same time, through semi-field experiments, it was verified that worker bees in the queenless colony can get the opportunity to mate and reproduce female offspring. This may be a reproductive strategy to maintain the development of the bee colony and cope with the early loss of the queen bee. These research results challenge the view that worker bees in superorganisms do not mate for life. More importantly, they provide a new perspective for a deep and comprehensive understanding of superorganism evolution and provide new ideas for the protection of endangered bumblebee species.

This research was supported by the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences.

Scientific review: Li Jilian, researcher at the Institute of Bee Research, Chinese Academy of Agricultural Sciences

Editor: Xie Yun and Wu Yuetong