Denise from Avondale writes
Southern Ag Pyrethrin Concentrate is labeled for spiders as a surface spray and should be mixed at 1 part concentrate with 4 parts water for severe infestations and 1 part concentrate to 9 parts water for maintenance applications. Pyrethrins do not leave a long residual. For spiders, since they die primarly through eating insects that have crossed the treated area, we recommend using a microencapsulated insecticide that will leave a longer residual like Cyzmic CS. Our Spider Control Kit has everything you need.
Answer last updated on: 12/19/2017