Citronella essential oil is a natural repellent against common pests, including flies, mosquitoes, fleas and spiders. Since it comes from a natural source, the lemon grass plant, citronella oil is environmentally friendly and safe to use around children and pets. Make an effective biopesticide spray to repel spiders from the entrances of your home with a combination of water and lemon soap and citronella oil.
Pour one quart of water into a spray bottle.
Add five drops of citronella oil.
Add one to three drops of lemon scented dish soap.
Shake the mixture well. Spray around the desired area to repel spiders.