The growing threat of antimicrobial resistance calls for alternative strategies to conventional antibiotics. Insects represent a promising source of antimicrobial peptides (AMPs) due to their potent innate immune responses. In this study, we investigated the peptide extracts from hemolymph of Hermetia illucens larvae as a bioresource of infection-induced AMPs. Larvae were challenged with Gram-negative (Escherichia coli) and Gram-positive (Micrococcus flavus) bacteria, and hemolymph-derived peptides were extracted and fractionated via reverse-phase high-performance liquid chromatography (RP-HPLC). Antibacterial activity of peptide fractions was evaluated in vitro against a panel of pathogenic strains, including multidrug-resistance isolated such as carbapenem-resistant Klebsiella pneumoniae. The peptide fractions were further analyzed by SDS-PAGE and LC-MS/MS to identify candidate AMPs. In parallel, shotgun proteomics on unfractionated peptide extracts enabled quantitative comparison across experimental conditions. In silico analysis using ProP 1.0, APD3, and CAMPR4 prediction tools revealed physicochemical profiles and machine learning-based scores consistent with antimicrobial function. Our integrative approach confirms that bacterial infection induces a diverse and bioactive immunopeptidome in H. illucens, supporting its potential as a sustainable platform for discovery of novel antimicrobial agents.