Abstract:A lightweight tobacco aphid detection algorithm called GEB-YOLO v8n was proposed to address the problems in field image acquisition, such as dynamic changes in ambient light and image blurring. Firstly, GSConv and the efficient channel attention (ECA) mechanism were innovatively introduced into the backbone network, and the rich image feature information and target-oriented ability of tobacco aphids were jointly output. Secondly, the bidirectional feature pyramid network (BiFPN) was introduced into the neck network, and the semantic expression ability and spatial information quality of the model for detecting tobacco aphid feature maps were enhanced. Finally, WIoU was introduced as the bounding-box regression loss function, and the model was enabled to better generalize to new and challenging tobacco aphid detection scenarios by dynamically focusing on complex samples. After the model structure re-parameterization and hyperparameter optimization, a network architecture for field tobacco aphid detection was formed. The results showed that the mean average precision (mAP) and F1 value of the improved model reached 91.8% and 90.4%, respectively, the number of parameters was reduced by 42.8%, the model memory footprint and floating point operations (FLOPs) were reduced to 3.5MB and 4.1×109, respectively, and the average inference time reached 3.6ms. A system for tobacco aphid recognition and counting in small-scale fields was developed based on the GEB-YOLO v8n model. The system had the dual functions of online image detection and video detection, and can intuitively display the detection results of the number of tobacco aphids on the interface, meeting the requirements of real-time detection of tobacco aphids in small-scale fields and mobile-end deployment. The improved lightweight GEB-YOLO v8n model can provide a method reference for the identification and phenotypic analysis of tobacco plant diseases and pests in the field environment.