1st off, knock down their webs. It takes 1/2 of their bodies strength to build their web. If you do it twice....you get the pic. Then, if you want to try Agent Orange, or some other poison, in order to supplement go for it.
Personally, I'd use regular poison, nothing to strong...also, WD40 knocks em down, so that you can step on em.
John 14:6