Abstract: Objective This study aimed to elucidate the evolutionary characteristics of key genes in digestion-related proteases in Eocanthecona furcellata and their adaptive mechanisms to predatory feeding habits， so as to provide a theoretical foundation for artificial mass rearing and biocontrol applications of Eocanthecona furcellata.Method Two predatory stink bugs （Arma custos and Eocanthecona furcellata） and two phytophagous stink bugs （Nezara viridula and Riptortus pedestris） belonged to Hemiptera： Pentatomomorpha were used to identified gene families of three digestion-related proteases （aspartic proteases， serine proteases， and cysteine proteases） across the four species using genome data. Key genes were screened through phylogenetic tree， collinearity analysis， and protein sequence conservation analysis. The expression of key digestion-related protease genes during different developmental stages were detected via quantitative reverse transcription PCR （qRT-PCR）. Weighted gene co-expression network analysis （WGCNA） was employed to explore the gene expression patterns of Eocanthecona furcellata across developmental stages and delineate the modular regulatory networks of digestion-related protease genes.Result Phylogenetic analysis of the digestion-related gene families of the four Hemiptera insects revealed that digestion-related protease genes were classified into three gene families， which were serine protease， cysteine protease， and aspartic protease families. Eocanthecona furcellata exhibited significant orthologous relationships with Arma custos in digestive protease genes （excluding self-clustering nodes）， while Nezara viridula showed closer orthologous relationships with Riptortus pedestris. Based on previous literature and observations during the rearing of Eocanthecona furcellata， combined with heatmaps of expression patterns in development stages of Eocanthecona furcellata， six key digestion-related protease genes were selected and designated as EfAP1， EfCP1， EfCP2， EfSP1， EfSP2， EfSP3. qRT-PCR results demonstrated that： the six genes were not expressed at egg stage； at the 1^st instar nymph stage， the relative expressions of the selected genes were significant higher than those at 2^nd to 5^th instar nymph stages and adult stage （P<0.05） except for EfCP2 （P>0.05）. Such results were consistent with the change patterns of FPKM of transcriptomic data. WGCNA analysis identified 35 co-expression modules， with aspartic pro-tease genes were predominantly clustered in the MEyellow module， cysteine protease genes in the MEturquoise module， and serine protease genes in the MEblue module， indicating that different protease genes possess independent regulatory networks.Conclusion This study preliminarily reveals the evolutionary characteristics of digestion-related protease genes， identifies， and screens three digestion-related protease gene families and six key digestive protease genes for Eocanthecona furcellata. The modular co-expression patterns of these genes suggest that the six genes are close related to adaptation to predatory feeding habits of Eocanthecona furcellata.