If you're looking for the best insecticide for spiders, the Martin's 82031984 Cyonara Lawn & Garden Spider Insecticide is a broad spectrum 0.5% Lambda-Cyhalothrin product used for the control of spider mites. Capable of being used as a mosquito insecticide and ant insecticide, this formula is also effective against fleas, aphids, fire ants, mosquitoes, chinch bugs and more. Available in quart bottles.

• Spider insecticide can be used on roses, vegetables, outdoors, flowers, flowers, trees, shrubs, lawns, yards
• Can be used as a mosquito insecticide and ant insecticide for effective use against fleas, aphids, fire ants, mosquitoes, chinch bugs and more
• Broad spectrum 0.5% Lambda-Cyhalothrin product acts as the best insecticide for spiders
• Lasts up to 8 weeks