mesh-covered green beans

I came across the beautiful beans last week in a plot at the Belmont Victory Gardens. Why are they covered with mesh? Does this keep the bean beetles off? They sure look great with no signs of beetle damage, unlike most plots around here. But then the adjacent and uncovered pole beans look good too.

Very nicely mulched with salt hay, too. I bought some stray/hay mulch that I will be spreading today in my gardens. I hope it looks as nice as this.