Just to back track a bit here but how common is this squash borer and what is the best way to deal with it? I have met another roof-top farmer who told me his squash/zucchini was going great until the squash borer set it and it killed his plants. I have some leafs that have been beaten up by the wind but he hinted that I might want to keep an eye out for the squash borer mildew/fungus. I've included a picture of the zucchini leaves below and wondering if anything looks suspicious. Also, what the best way to take care of this plant - trim older leaves from the top / spray fungicide - is there any natural fungicide, etc???
I know there's some great experience on this site. Thanks in advance for your help...
It seems there's some confusion here regarding 3 separate issues. The squash vine borer does just that. It burrows into the stem close to ground level and the burrowing larvae destroy the internal vascular tissue and cause the whole plant or the invaded runner to wilt and die.
The squash bug is one of the most common and troublesome pests attacking squash and pumpkin plants. Both nymphs and adults suck sap from the leaves and stems, apparently at the same time injecting a toxic substance into the plant causing a wilting known as Anasa wilt of cucurbits. This closely resembles bacterial wilt, a true disease. After wilting, vines and leaves turn black and crisp, and become brittle.
The cucumber beetle (striped, spotted) causes bacterial wilt, squash mosaic virus.
Then there is powdery mildew.
The squash vine borer does not cause mildew/fungus. Depending on the specific problem, there are different controls. Fungicide is one to use regularly as a preventative, but keeping a close eye on the stems looking for signs of 'sawdust' from boring larva and for the other pests will help minimize damage.