Answer: I'm glad to hear that you're finding benefit from our service! And congratulations on your "sharing" attitude - it's a growing trend among American gardeners, and one we try to foster through education and understanding of the natural world, and our part in it.
There aren't many diseases that the cucumber, bean and tomato share (they're all in different plant families), and none that fit your description. Warm, humid/wet weather is favorable for the growth of fungal and bacterial diseases, and it's possible that your plants are suffering from some kind of infection. Late blight, caused by a fungi (Alternaria solani) doesn't infect beans or cukes. Bacterial spot (caused by Xanthomonas vesicatoria) does cause leaf spots on cukes and tomatoes, but doesn't affect beans. Since you describe the spots as the same on all the plants, I'll bet they're the cause of some pest insect (your first intuition!). Look for flea beetles, tiny, shiny black specks that disappear as you approach (they jump like fleas, hence their name). They'll eat most anything, and are most happy in dry, hot weather. They're not easy to control, but since their damage is mostly cosmetic, control is seldom necessary. If they start to defoliate your plants, that's cause for action. So keep sharing, and enjoy the harvest!
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