Aphids are known to transmit plant viruses to various crops and plants, but they do not pose a direct threat to human health. These tiny insects can act as carriers or vectors for plant viruses, spreading them from one plant to another as they feed. Here are some of the diseases that aphids can transmit to plants: 1. Cucumber mosaic virus (CMV): This virus affects a wide range of plants, including cucumbers, tomatoes, peppers, and melons. Symptoms of CMV infection in young plants include mosaic patterns on plant leaves sometimes, stunted plant growth sometimes, and deformed fruits. 2. Potato virus Y (PVY): PVY is a common virus that affects potatoes, peppers, tomatoes, and other solanaceous crops. Infected host plants also may exhibit yellowing, leaf curling, and reduced yield. 3. Turnip mosaic virus (TuMV): TuMV infects a variety of plants, including turnips, radishes, and other cruciferous vegetables. Symptoms include mosaic patterns on leaves, stunted plant growth sometimes, and distorted or discolored foliage. 4. Bean yellow mosaic virus (BYMV): BYMV affects leguminous plants such as beans, peas, and lentils. Infected plants may show yellowing, mosaic patterns on leaves, and reduced yield. 5. Barley yellow dwarf virus (BYDV): BYDV primarily affects cereal crops such as barley, wheat, and oats. Infected plants may exhibit stunted growth, yellowing, and reduced grain quality. These are just a few examples of plant diseases and other insects that aphids can transmit harm plants. It’s important to note that not all aphids carry viruses, and the severity of the disease depends on various factors, including the specific virus, the host plant, and environmental conditions. However, aphid infestations should be taken seriously, as they can contribute to the spread of plant diseases and cause significant damage to crops and ornamental plants.