Most ladybirds have a one year life cycle, so you probably haven�t done any harm. Depending on when you decided to prune your shrub. If you are genuinely concerned, why not give the bits you prune a good shake to remove the existing life there? And if you have a real worry, why do it while the bugs are still there in large numbers? Wait till they leave of their own volition.
Ladybirds are very useful as they eat many of the creatures that eat our plants. Life�s wonderful cycle. Never kill anything that doesn�t need killing. Nature has its own way of dealing with stuff. It�s done well enough without us for the last few billion years! (�Til we came along and tipped the balance! - But she will recover. We may not be around to see it, but life will prevail.)