Insect-transmitted plant diseases pose an important threat to food security worldwide, because insect vectors can transmit viruses, bacteria, fungi, and phytoplasmas. Insects, owing to their feeding behavior and adaptability, can spread disease-causing agents rapidly and cause large yield losses. Understanding vector–pathogen–host interactions is essential for developing sustainable solutions to insect-transmitted plant diseases and facilitating more effective control measures. Traditional diagnostic tools, such as symptom-based assessment and microscopy, can be useful, but tend to be slow and imprecise. Molecular diagnostics, including PCR, ELISA, isothermal amplification, next-generation sequencing, CRISPR-based assays, and biosensors, are powerful tools that allow land managers to implement sensitive and rapid field-deployable detection assays. Their availability will undoubtedly strengthen surveillance, early warning systems, and epidemiological monitoring. Management strategies need to adopt an integrated approach to simultaneously target vectors and pathogens. Cultural practices such as crop rotation, synchronized planting, and residue management reduce disease pressure and incidence. The use of physical barriers and mechanical methods reduces the number of vectors. Biological control and potential use of insect- and pathogen-resistant varieties, either through breeding or genome editing, provide long-term, sustainable, and environmentally responsible options. The judicious use of chemicals for biological control as part of an Integrated Pest and Disease Management (IPDM) context is important. Emerging molecular tools, such as RNA interference and paratransgenics, provide future avenues for control. This chapter has provided advances in diagnostic and integrated strategies, with a focus on cost-effective, eco-friendly, and scalable approaches that are important for reducing insect-mediated plant disease incidence and maintaining agricultural productivity.