Terro 2300 Aerosol Spider Killer
From a name you know and trust, TERRO Spider Killer Spray will get the job done. It is made with two synthetic pyrethrin ingredients, which act as neurotoxins, so although not natural, it still breaks down and is relatively environmentally friendly. The carrier is a mineral oil based substance, so once sprayed, it offers a residual effect that keeps killing spiders for up to 12 weeks. It comes complete and ready to use in a can, spray it on webs or where spiders are lurking, and let the active ingredients do the rest.