Try oriental long squash(OPO), it is is easy to grow and is almost free from disease and insect attacks. Fruits are picked when immature and cooked like squashes. see the link

http://www.evergreenseeds.com/calgouropo.html

beshkie how big is your garden? Seriously, the plants you have had troubles with are all spreaders needing a good amount of room. If they are fighting each other for space above ground plus below ground fighting for the nutrients and the limited amount of good penetrating rain then they are stressed.

Stressed food production plants are like a beacon to be attacked by insect and fungal diseases.

Next year allot them more space and loosen a wider amount of soil for their roots to penetrate laterally as you plant them. More space gives YOU more space to get in there and check for borer holes you can fish out the larva, kill it and the plant will heal.