The problem with aphids: a) you have to hit them directly with the soap/neem, b) the soap/neem may not kill the eggs, and c) they lay their eggs in the soil as well. I just eliminated the aphids from my plants by giving in and releasing ladybugs inside my house. This particular package was difficult to figure out how to open, and I ended up accidentally releasing a lot more than I had intended. The first couple days, my house looked like ladybug central. But I have a sense of humor about it, and chalked it up to a learning experience. It's been about a week now, and I can hardly find ladybugs anywhere - they have eliminated the aphids and their eggs, and are starting to move on and/or die off. (I'm in a really old house, and know there are gaps in places like some of the windows where they can get out.) If your house is better sealed than mine, you will likely find them gathering at the windows trying to get out after the aphids are gone - just scoop them up and throw them outside.
Tips on releasing ladybugs inside the house:
- Put the package in the fridge for a bit before attempting to open it, which will cause them to go semi-dormant. Then when you do open the package, you can scoop out just however many you want, and put them where you want.
- Give them a cotton ball that's been soaked (but not dripping) in water after releasing them, as they will be thirsty.
- Some ladybugs come in a pouch-type of package, which you can just snip off the corner and release one at a time. The package I received was like a plastic butter tub with a mesh-type lid that had a ring around it. No instructions came with how to open it. There are two little tabs as part of the ring, and only one would come off. I thought this was like a milk jug ring, but it's not - the ring will not come off. Turns out all that removing the tab does is expose the edge of the lid - you can then pull the lid off from there, just don't bother trying to pull on the ring. There are likely many more package types out there, but the thing to keep in mind is that if they wake up while you're trying to figure how to open the pack, put it back in the fridge to calm them down again.
- Put the rest of the ladybugs back in the fridge, in case you find that you need to release more later.
- Don't expect them to stay where you put them - they're not trained animals, after all. They will stay on your plants until the aphids and eggs are gone, then they'll start searching for a new food source, so they'll start to be found all over. But like I said already, they'll soon congregate at the windows, trying to move on.
- Don't release the ladybugs right away after you've used soap/neem, as it will kill them, too.
There's likely someone out there who has done this more than once, and who has more tips, but this is what I've found so far. Hope it helps you.