Biodiversity in and around Greenhouses: Benefits and Potential Risks for Pest Management

Aphid Recognition and Counting Based on an Improved YOLOv5 Algorithm in a Climate Chamber Environment

Due to changes in light intensity, varying degrees of aphid aggregation, and small scales in the climate chamber environment, accurately identifying and counting aphids remains a challenge. In this paper, an improved YOLOv5 aphid detection model based on CNN is proposed to address aphid recognition and counting. First, to reduce the overfitting problem of insufficient data, the proposed YOLOv5 model uses an image enhancement method combining Mosaic and GridMask to expand the aphid dataset. Second, a convolutional block attention mechanism (CBAM) is proposed in the backbone layer to improve the recognition accuracy of aphid small targets. Subsequently, the feature fusion method of bi-directional feature pyramid network (BiFPN) is employed to enhance the YOLOv5 neck, further improving the recognition accuracy and speed of aphids; in addition, a Transformer structure is introduced in front of the detection head to investigate the impact of aphid aggregation and light intensity on recognition accuracy. Experiments have shown that, through the fusion of the proposed methods, the model recognition accuracy and recall rate can reach 99.1%, the value mAP@0.5 can reach 99.3%, and the inference time can reach 9.4 ms, which is significantly better than other YOLO series networks. Moreover, it has strong robustness in actual recognition tasks and can provide a reference for pest prevention and control in climate chambers.

Effect of the Landscape on Insect Pests and Associated Natural Enemies in Greenhouses Crops: The Strawberry Study Case

Compared to open-field crops, the influence of the surrounding landscape on insect diversity in greenhouse crops has been poorly studied. Due to growing evidence of insect influx in greenhouses, identifying the landscape properties influencing the protected crop colonization by insect pests and their natural enemies would promote the improvement of both pest prevention and conservation biological control methods. Here, we present a field study on the effect of the surrounding landscape on the colonization of greenhouse crops by insect pests and associated natural enemies. By monitoring 32 greenhouse strawberry crops in the South West of France, we surveyed crop colonization by four insect pests and four natural enemy groups over two cultivation periods. Our results showed that the landscape structure and composition could have contrasting effects on insect colonization of greenhouse crops so there could be species-specific effects and not general ones. While the degree of openness of greenhouses and the pest management practices modulated insect diversity marginally, we also showed that seasonality represented a key factor in insect crop colonization. The various responses of insect pests and natural enemy groups to the landscape support the idea that pest management methods must involve the surrounding environment.

Installation of hedgerows around greenhouses to encourage biological pest control: Farmers' perspectives from Southeast Spain

The intensification of agriculture has led to the deterioration of various ecosystem services, including pest control. The installation of hedgerows around greenhouses is presented as a viable option to maintain and favour natural enemies of pests. Despite the economic and environmental advantages of this type of facility, farmers are reluctant to implement it. Therefore, it is necessary to determine the factors that influence the decision to install hedgerows and the most appropriate incentives to promote their establishment. This article analyses intensive agriculture in Southeastern Spain. The application of cluster analysis techniques allowed the detection of four types of farmers in relation to this practice. The factors that drive its installation are an increase in the effectiveness of biological control, a reduction in the use of pesticides and the possible economic and environmental benefits. As a barrier, a lack of knowledge of and confidence in the effectiveness of this practice stand out. Among the measures to encourage their installation, the most valued are training and advice and recurring payments for the ecosystem services generated. The results obtained can be useful for policy makers in regions in which the installation of non-crop vegetation is promoted.