I put so much Sevin on those squash you couldn’t see that the plant was green. All it did to the bugs was give them a snow day. Think I saw a few of em making snowmen.Have you tried growing them vertically? I have not done it, don't grow squash, but have seen some videos and it makes sense. Get the plant up off the ground and keep the lower limbs pruned off to prevent hiding places for the bugs.
Sevin dust isn't what it used to be, it no longer contains carbaryl and now contains zeta-cypermethrin.