Abstract: Eusocial insects, such as bees, ants and wasps of the Hymenoptera and termites of the Blattodea, have significant diversity in morphology, behavior and life cycle, although their genetic background and genetic basis are consistent in a population. Most eusocial insects show different caste structure and life span differentiation. In these structure, queens tend to have a longer life span than workers, and their reproductive capacity is only owned by one queen or several queens, while the other members of the group can only act as workers. However, in some species, the caste structure has certain plasticity, and individuals can switch from one caste or behavioral phenotype to another according to specific environmental clues. Due to the common genetic background between different castes, the diversity of eusocial insect populations is largely caused by the gene transcriptional differences between individuals. This means that epigenetic mechanisms characterized by modifying gene expression without changing the gene sequence may play an important role in eusocial insects. Evidence had shown that epigenetic regulatory mechanisms such as DNA methylation or RNA methylation, histone post-translation modification and non-coding RNA had been proven to affect eusocial insects in many aspects, such as caste structure, longevity differentiation and aging. In this article, we reviewed the research progress of these epigenetic regulatory mechanisms and their different roles in insects, so as to deepen the understanding and cognitive degree of the origin and behavior evolution of eusocial insects. In the future, epigenetic regulatory mechanisms have potential application value in the research and development of anti-aging drugs, treatment of aging-related diseases, and slowing down the aging process of organisms.

Key words: Epigenetics, eusocial insect, caste structure, longevity differentiation, aging