Wings can only heal other enemies on touch (and cannot be healed themselves), so pushing them away with your shield can prevent them from undoing the damage you've dealt. Due to their small size, they can easily be cornered or trapped between two Knights. They tend to either wander aimlessly or stay put unless there is a damaged enemy around, so they make easy targets. Poisoning enemies will reduce the Silkwing's ability to heal, and curse causes them to take damage for each heal tick they perform, taking them down quickly.
Most problems with Silkwings come with their habit of healing and following large, dangerous monsters such as Lumbers and Trojans and becoming hard to safely damage as a consequence. The easiest ways to amend this are either to use attacks with a large coverage area, to light the Silkwing on fire, to freeze the Silkwing (and by extension the larger, more dangerous monsters accompanying it), or to wait until it completely heals the monster and then kill the Silkwing before you damage other monsters (as previously mentioned, Silkwings either stay put or wander aimlessly if there are no damaged enemies nearby). Quickly taking out all the other enemies before killing the Silkwings can (sometimes) work as well.
In short, Silkwings are spawned with other strong monsters like Lumbers or Trojans most of the time. Try to defeat the Silkwings before focusing on the other monsters.
Quick Glance Gear:
Pending