The onion aphid, Neotoxoptera formosana, poses a significant threat to Allium crops worldwide, causing considerable economic losses and quality degradation. To develop effective pest management strategies, it is crucial to understand the feeding behavior and life history of this pest on different Allium crops. In this study, the electrical penetration graph (EPG) technique was used to monitor the thorn-feeding behavior of the onion aphid on 4 Allium crops: leek, chive, garlic, and shallot. The EPG data revealed distinct feeding patterns, with garlic and shallots being more preferred hosts than chives. Additionally, the aphids primarily fed on the phloem in garlic and shallots. Analysis of life history trait showed that chives provided the most favorable conditions for aphid development and reproduction, while leek exhibited relatively unfavorable conditions. Examination of leaf histology also revealed differences among the crops, which may influence aphid feeding behavior. This study provides valuable insights into the interaction between the onion aphid and different Allium crops, aiding in the development of comprehensive pest control strategies to minimize crop damage and economic losses. The use of advanced techniques like EPG contributes to a more detailed understanding of aphid behavior and shows promise for improving pest management in other plant-pest interactions.