Here's a tactic.

That would not be good idea. Once they are glued to the wall they barely pose any treat. She would uselessly spend mp that are used for tread manipulation as well. Aside from that if it is even similair to real spider poison, it would corrode her own tread.

But if they die like that it would raise her experience and she could level up and restore her mp. And between thread manipulation and poison synthesis she is draining her mp too fast anyway. She needs a move that is more effective and wide spread so she can focus her energy on the Bugaretch.