I struggled with the same problem when I lived in the city... Just a guess, but I finally decided it was simply because there were not enough pollinators in my area.. neighbors and everyone around me sprayed and I think this simply killed too many pollinators. Out here in Catalina I don't have that problem ... I do use things to draw in bees and NEVER use anything that might kill a bee or worm. I line my garden fence with berries and of all things asparagus seems to draw more bees than anything else when blooming ... l've noticed in recent days that my humming bird feeder in the garden really attracts bees.... as you know its been really windy of late and this rocks the feeder and spills the sugar water and the bees love it. You might try setting a dinner plate in your squash row filled with 1 cup sugar in a cup or two of water I bet if you have many bees they will come to it. Be careful this time of year they are swarming and seem to be more active in early morning and late afternoon during cooler times. Also keep an eye out for ants because they love sugar water also.With pollinators I have good fruit set and much less misshapen fruit. I know its frustrating .. hang in there... I just planted my fall crop of tomatoes and finally have the first tomatoes just getting ready to turn red and getting excited about my first BLT...
