This is a great example of working with nature! Our Beach Plum tree was under siege from aphids, until the ladybugs showed up. The ladybug larvae really cleaned up and the tree is doing just fine.
Honestly, I was a bit concerned. It can be upsetting to find your plants under attack. But we let nature do its thing! I’ve never seen so many ladybug larvae in one place before.
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The dowside is they'll disappear as soon as the bugs do and leave it open to be re-infested..
It's best to find out why you're having the problems in the first place, (with aphids it's usually overcrowding, sickly plants, or a poorly maintained garden/patch of weeds nearby.)
You don't typically get infestations on healthy & happy plants.
Some plant get overwelmed from aphids, even the plant was healthy before. Especially broad beans, cive, in springtime also elderberry trees. And the ladybug itselve isn't that good in eat that pest, it's the larva of them. If you're having water suppy nearby, you can rinse them aphids away with water at first glance, then the ladybugs and their larvas can do the rest.