Does Permethrin Kill Spiders (Hobo & Brown Recluse)?

There has been recent news on how effective spider repellents are in preventing bites from dangerous spiders like tarantulas, black widows, and brown recluses.

Permethrin is one natural agent used as an insecticide which is also known as NIX (a prescription skin cream) when applied topically over clothing or bedding; this chemical provides protection against insects such as ticks, fleas, spiders, and mosquitoes for up to 24 hrs.

Does Permethrin Kill Spiders?

Yes. Permethrin is effective at killing spiders both by contact and also by ingestion.

studies looking at the effect of permethrin on the spider Cybaeus show that it reduces locomotor activity, causes profound coxal rigidity, decreases survival time, produces drooping abdomens, and eventually leads to death.

Permethrin will kill spiders on contact because it is toxic to Arthropods (because it contains the active ingredient permethrin).

The EPA has granted general registration for most outdoor residential uses of this product, including lawns, turfgrass, and ornamental plants.

There is little to no risk with using this product outdoors. Before application outdoors, re-read label restrictions.

Limitations may apply to:

  • Hedges or trees that are close together or next to the home;
  • After applying an insecticide with live activity;
  • Before fogging;
  • Within 72 hours after treatment of any insects with bacillus thuringiensis products;
  • Stone walls, concrete fences, and other concrete surfaces adjacent to property lines that are less than 8 feet high above the ground.

It is important to note that permethrin is not lethal to humans, but it can be toxic if you are exposed for a prolonged period of time. It will take about two weeks for the permethrin to break down and leave your body.

If you have any questions or concerns, contact your doctor immediately.

FAQs on Permethrin for Spiders

Does permethrin kill spider mites?

Yes, it does. A majority of plant disease control products use some permethrin active ingredient.

For normal garden pests the usual advice is the following: Spray on a warm sunny day, in the late evening when insect pest activity is minimal between 6 – 8 pm, but before sunset in case of long days – this will allow for passive blow-down and hot temperatures to be effective.

Make sure that everyone stays off weeds for 24 hours after spraying (especially children) and that there are no pet animals in the area when spraying; use exclusion netting during treatment if necessary, to avoid contact with treated plants; do not water within 2 hours of application.

There are many excellent brands of permethrin products available today, and you can find one in the home supplies store near you.


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