Understanding the sublethal effects of insecticides on non-target insects is essential for integrated pest management (IPM). This study aimed to evaluate the differentially expressed genes (DEGs) in the testes of Ceraeochrysa claveri adults exposed to pyriproxyfen during the larval stage. Larvae (0–12 h) were fed Diatraea saccharalis eggs treated with pyriproxyfen (50 and 100 mg a.i. L⁻¹) for 10 days. After this exposure, the larvae were fed untreated eggs until pupation. The testes from the adults were extracted for RNA extraction, library construction, and sequencing. The reads were de novo assembled, and the genes annotated based on their ORF homology. A total of 46 DEGs were identified for the 50 mg a.i. L⁻¹ vs. control, 47 DEGs for the 100 mg a.i. L⁻¹ vs. control, and 64 DEGs for 50 mg vs. 100 mg a.i. L⁻¹ treatments. To validate the DEGs through RT-qPCR, the genes BPHL, Large2, MLX, and Talin-1 were selected. The results indicate that the exposure of C. claveri larvae to pyriproxyfen could alter the gene expression and lead to delayed effects in adults. This study provided a novel approach for assessing the sublethal effects of pyriproxyfen C. claveri and contributed valuable information to enhance IPM strategies.