Beginner Gardening: Similar leaf symptoms on squash, tomatoes, and beans, 1 by Hortlove

Hortlove wrote:
Hi all. This is my second year vegetable gardening and I did a few things different this year than last (like not planting 10 squash plants), but I have noticed a drying, pitted pattern on the leaves of my beans first, then the tomatoes, and finally the squash. They are all in the same bed which leads me to believe that the same pest has merely moved on to infest the other plants. However, while I know I have mild whitefly and aphid problems (I grow organically and had control until the weather began heating up), I don't think they are the cause of these leaf symptoms. Overall, the plants seem like their vigor is reduced, since I have only just now set tomatoes, there are few squash flowers, and the beans keep dropping their flowers. Any and all advice is appreciated!