Aphid problem

I have a lot of aphids in my garden this year. I don't spray them except for a sharp jet of water, and I do see many more ladybugs and other predators as the years have gone by. But this crop of aphids was overwhelming. Here they are on a Nassella pulchra (Purple Needle Grass) seedling. I thought that the native plants and particularly the hardy grasses would be immune. I was wrong.




















Closer.




















They ended up on my pole beans. Here's the bamboo trellis that I built with baby bean plants at lower left. Nearby bush beans seemed unaffected.