Alliance hummm ..
(LVL 32-36) Plains Creeper Arathi Highlands 12-20% Drop Rate.

*Duskwood spiders (Black Widow Hatchling, Green Recluse, Carrion Recluse, Naraxis, Venom Web Spider, Pygmy Venom Web Spider) (LVL's 19-27) 6-12% Drop Rate.
Spider Silk: "214334"