Mechanisms Responsible for Larval Diapause in Anastatus japonicus Ashmead, Shown by Integrated Transcriptomic and Proteomic Analyses

Diapause enables insect survival in unfavorable environments. The parasitic wasp A. japonicus, a natural enemy of several fruit-tree pests, undergoes larval diapause. Previous work has shown that larval diapause in A. japonicus can be induced by medium temperatures in combination with short-day photoperiods; however, the molecular functions associated with this response remain poorly understood. Here, integrated transcriptomic and proteomic approaches were employed to investigate the molecular signatures associated with larval diapause in A. japonicus. The identification of 3399 differentially expressed genes and 3112 differentially expressed proteins was carried out between diapause and non-diapause larvae. Among these, five gene–protein pairs showed consistent differential expression, including farnesol dehydrogenase, crystallin (associated with longevity-related pathways), forkhead-associated (FHA) domain-containing proteins, and the detoxification enzyme cytochrome P450. These findings show that larval diapause in A. japonicus is accompanied by extensive physiological and biochemical remodeling, and juvenile hormone-related signaling is likely involved in this process. In summary, these results provide insights into future gene function research, especially with regard to the mechanism of larval diapause in A. japonicus.