1, if you don't water it for a long time, there will be white spots on the onion leaves, and you will feel concave when you touch it with your hands.

2. If white spots appear when the moisture is normal, and there is a protruding feeling when you touch it with your hands, it is that you are sick, or you have bugs and can't eat them.

Extended data:

1, the white spots on onion leaves may be caused by pests and diseases, namely gray mold, thrips and liriomyza sativae. The common feature of these three diseases is that there are irregular white spots on the leaves of plants at the time of onset, so it is necessary to distinguish them in the prevention and treatment of diseases in order to prescribe the right medicine.

2. At the onset, round or oval white spots appear on the leaves, which extend downward from the tip of the leaf. In severe cases, the leaves curl and die, usually in a high temperature and rainy environment. During control, 750-fold solution of 10% acetamiprid, 2% avermectin 1500-fold solution, 50% procymidone 800-fold solution, 50% acetamiprid 4000-fold solution and 30% mirex 1000-fold solution are mixed every 5 ~.

3. Also known as onion leaf fly, it belongs to Diptera leaf miner, which mainly harms onions, leeks, onions and other vegetables. When this pest appears, you can see winding tunnels on the leaves. After the leaves are eaten, only two layers of white and transparent leaf epidermis are left. In the early stage of this pest, many white spots can be seen. In severe cases, onion leaves only leave the epidermis, which affects the growth of plants.