How do you counteract spider webs?
Solution 1:
Necessary evil I'm afraid. There is no stat that reduces their effectiveness.
The best defense that I've found is more complete, tiered tower coverage. If you tier your towers such that you have your main line, and then longer range towers with their backs to walls or cliffs covering the empty space between the crystals and your main line, then they don't have any empty space to run amok. Of course this changes per map, tower setup, and toon, but I've found that Deadly Striker towers and some Huntress bombs/mines are especially good at dealing with them so you're more free to roam unmolested. :)
I'm definitely interested in hearing any other strategies for dealing with them as well!