In agricultural production, pest control is essential to ensure stable crop yields. In recent years, especially in the planting process of China's four major staple grains - rice, wheat, corn, and potato, the frequent occurrence of major pests and diseases such as wheat scab and stripe rust, rice sheath blight, and corn spot disease has brought great challenges to agricultural production. These diseases not only directly threaten the safety of grain and oil production, but also may lead to a significant decline in crop yield and serious damage to quality, which in turn hurts the overall development of the agricultural industry. It is predicted that by 2024, the pest and disease situation of these food crops will be even more severe. It is estimated that the area of major pests and diseases of wheat, rice, corn, potatoes, and other food crops will reach a staggering 2.04 billion mu nationwide, an increase of 15% over the average level in 2023. This means that more than 70% of food crop-producing areas will be threatened by these pests and diseases, and agricultural production is facing unprecedented risks and challenges. To cope with this critical situation and improve agricultural production efficiency, timely detection and early prevention of plant diseases have become crucial.
With the rapid development of artificial intelligence and computer technology, deep learning algorithms have shown strong potential in many fields, such as agriculture and forestry, medicine, finance, and other fields. Deep learning has become a popular research direction and has achieved excellent results in the fields of natural language processing (NLP), image processing, and object detection. In the field of pest identification, we try to use deep learning algorithms and computer vision technology to realize the automatic identification and classification of pest and disease images, which greatly improves the accuracy and efficiency of pest and disease identification.
Among the many deep learning models, convolutional neural networks (CNNs) have performed well in the field of pest and disease identification due to their unique advantages. At present, a variety of CNN-based pest identification methods have been proposed, such as AlexNet, VGGNet, ResNet [1–3], etc., and these models have achieved excellent results in the field of pest and disease identification. For example, Cheng et al.[4]achieved remarkable results with the application of improved AlexNet in the classification of strawberry pests and diseases, with an accuracy rate of 98%. At the same time, the work of Alatawi et al.[5]also revealed the great potential of the VGGNet model in plant disease identification.
With the deepening of research, it is found that the expressive ability of the model can be further improved by designing deeper neural network structures, to extract more discriminating depth features. However, this also poses a problem: a deeper network structure means more model parameters and higher computational complexity, as well as higher requirements for storage devices and computing resources. This makes existing deep learning models face certain challenges in practical applications, especially when deployed on end-user mobile devices with limited resources.
To solve this problem, researchers have begun to explore how to reduce the complexity and computational cost of the model while ensuring the accuracy of the model[6–7]. Among them, the proposal of a knowledge distillation (KD) method[8] has attracted extensive attention. This approach guides the learning process of a smaller, less parameter-rich model (the student model) by utilizing a larger, parameter-rich model (the teacher model). During the training process, the teacher model "distills" the knowledge and feature information it has learned into the student model so that the student model has lower complexity and computational cost while maintaining high accuracy. To let the students better imitate the teacher, we also set the temperature parameter T to be dynamically adjusted according to the predicted value output by the student model and the loss value of the true label. This method can not only simplify the model structure on the premise of ensuring the accuracy of the model but also improve the feasibility and generalizability of the model in practical application. Therefore, the pest classification method based on knowledge distillation provides a new idea and method for solving practical problems in the identification of crop diseases and pests.
The rest of this article is organized as follows: First, we reviewed the work in Section 2. Then, in the third section, we will elaborate on the details of the ideas and models presented. We then present the experimental results and comparisons in Section 4 and finally summarize our work in Section 5.