# Advancements and Prospects of Electronic Nose in Various Applications: A Comprehensive Review
## 3 Application Areas
### Disease Diagnosis
#### 3.3.3 Invasive Insect-Pest Infestations
[198] delved into the realm of forest pest management, with a particular focus on combating the threat posed by the Emerald ash borer (EAB). This highly destructive nonnative insect pest has emerged as a major concern, exerting a detrimental impact on various ash tree species since its introduction from Eurasia to the United States in the 1990s. The primary focus of their study was to assess the efficiency of a dual-technology electronic nose/gas chromatograph device for the early identification of EAB infestations in green ash trees. This technology offers the potential to enhance the planning and implementation of EAB pest control measures across various settings, including natural hardwood stands, plantations, and urban environments. Detecting concealed EAB galleries during the early stages of infestation is crucial for optimizing pest management strategies. [PERSON] et al. [198] investigated VOC emissions from sapwood to discern the presence of EAB infestations across distinct EAB decline class levels. They unveiled significant variations in VOC sapwood profiles among trees categorized under different EAB decline classes. VOC metabolites present in sapwood headspace volatiles exhibited varying types, quantities, and composition across different sample types. An important discovery emerged as they identified distinctive e-nose \"smellprint\" patterns, originating from diverse VOC compositions in the headspace volatiles of sapwood cores. These patterns provided insights into the severity of EAB infestations (decline classes) and functioned as chemical signatures of varying infestation levels. Moving beyond pattern identification, the study introduced specific VOC metabolites as chemical biomarkers for differentiating healthy trees from those infested by EAB. This breakthrough held promise for assessing the health status of individual trees based on their VOC emissions. Despite limited differentiation between ash decline classes using UHPLCMS for major bark phenolic compounds, the dual-technology e-nose exhibited significant capabilities in distinguishing between uninfested and EAB-infested trees through sapwood VOC emissions. Table 6 provides a comprehensive overview of various studies that utilize electronic nose technology for the early detection of invasive insect-pest infestations in plants. Each study employed distinct methods and approaches, resulting in valuable insights and potential solutions for managing such infestations. The results showcase the promising capabilities of electronic noses in contributing to improved agricultural practices and sustainable pest management. In summary, the application of electronic nose technology has demonstrated remarkable potential across diverse domains of pathology and diagnostics. From human clinical pathology to veterinary-wildlife pathology and invasive insect-pest infestations, these studies collectively highlight the versatility and effectiveness of electronic noses in detecting VOCs and unique odor profiles associated with diseases. By harnessing the power of