Cucumber with Squash Experiment gone wrong

Well I tried planting both cucumber and squash in the same bed. Which is said to be a big no-no. The reason why you should not, is because they can attract the same pests. However I would think the same thing would apply with multiple cucumber plants in the same bed, or multiple squash in the same bed. But we all grow multiple plants of the same species in beds. I just didn't see how a squash, and cucumber bed would be any different than a bed filled with cucumber. So I tried it, and all the squash plants died from squash vine borers. Now these borers do plague my squash every year. They are very bad around here and it's almost impossible to keep these squash healthy. I will say however that these seemed to get hit quicker. But the borers do not go after the cucumber, and I just dont see how the cucumber could have increased the amount of these pests being attracted to the squash. Please let me know if you think so.
Now having to do with the cucumber. I believe the main reason why the cucumber didn't make it, was because they got blasted by the sun. We had 100+ degree days this past month, and usually we dont get our first 100 degree day until late July. But this year it hit early June, a full month before we are used to it. Cucumber do not like these temps and full blast of our south Texas sun. I should have covered them, but I didn't get to it quick enough and they suffered. This stressed out the cucumber which allowed diseases like powdery mildew to run ramped. At least this is my theory. Maybe having the squash near by could have affected the powdery mildew and caused it to increase faster? I am not sure really. Let me know what you all think on that.