Are you looking for the best spider killing insecticides and sprays? Then you’ve come to the right place.

In this Pest Strategies product review you can expect to learn:

  • What kind of equipment to use
  • What kind of insecticides to use outside
  • What kind of insecticides to use inside
  • What kind of results to expect

Top 4 Best Spider Sprays Reviewed

Short on time or just want a quick answer?

Check out our list below for a summary of our results. Keep on reading to learn more about dust mites and the sprays and treatments that kill them.

  1. Cyper TC
  2. Bifen L/P
  4. Delta Dust

1. Cyper TC

The active ingredient in Cyper TC is Cypermethrin, another member of the pyrethroid family, but at 25.4% concentration in the bottle.

When you open it, the smell is very strong and we recommend this one only for outdoor use. The label says you can use it inside but the smell says otherwise.

Because it’s so concentrated and so cheap, it makes an excellent insecticide for yard spraying. You can use a lot of it to kill just about anything that comes into your yard.

Aside from its noticeable smell, this has all the same properties as Talstar and Suspend; a very fast knockdown (because it’s so concentrated), a good residual impact, and very strong resistance to wind, rain, and sun.

The Good:

  • Very fast knockdown
  • Good active ingredient
  • Broad spectrum insecticide
  • Excellent for doing yard sprays

The Bad:

  • Really strong odor


  • Crack and crevice spray
  • Broadcast spray for outdoor use
  • Up tp three months control

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2. Bifen L/P

Bifen L/P is a granular insecticide whose active ingredient is Bifenthrin. As a granule though, it’s formulated to be water activated.

This makes it a perfect product to use in wet, rainy conditions. The rain gradually melts the granules and they spread out over the ground forming a protective barrier just as if you’d sprayed Talstar or Cyper out of a tank.

The downside is that too much sun will scorch the granules and destroy them. If you spread this during the summer, make sure you water the yard after you spread them out with your hand spreader. They are a bit heavy though, so be prepared for that.

Granules are cheap and easy to use, but they are dusty. You’ll probably get granule dust all over you when you’re spreading them, as well as a bit of the granules themselves.

Pest control technicians take a shower after work to get all the chemicals off them; you’ll have to do the same thing.

The Good:

  • Easy to use
  • Water activated
  • Good active ingredient

The Bad:

  • Fairly heavy
  • Dust will get all over you
  • Must water the yard after treatment


  • Great choice for outdoor application
  • Granular insecticide
  • Water activated

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The active ingredient in D-Fence SC is Deltamethrin at 4.75%. Deltamethrin has a low odor, and when used in accordance with the label, it is non-staining. This pesticide does a fantastic job of controlling a broad spectrum of insects, including spiders and even some of the more difficult spiders to get rid of.

Because of its unique design, D-Fence SC can even treat ornamental plants and bushes around your property to take the fight directly to the source of your pest problem. You can even mix it with other products such as insect growth regulators to deal with multiple issues at once.

In addition to all of the other great points that we’ve made about this product, it can be used indoors or outdoors without any reduced effects.

It even has residual effects so that it keeps working for 90 days after it has been applied. If using it for a large area, it is best used outdoors, and if you are using it indoors, it is best applied to floors boards and as a crack and crevice treatment.

The Good:

  • Lasts for 90 days after it’s been applied
  • This is a broad-spectrum pesticide
  • Defence-SC can be mixed with many other products without clogging.

The Bad:

  • You will need a sprayer to apply it correctly.


  • Lasts for 90 days after it’s been applied
  • This is a broad-spectrum pesticide
  • Defence-SC can be mixed with many other products without clogging.

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4. Delta Dust

Delta Dust is a dry formulation of Deltamethrin, the same active ingredient in Suspend. This has to be used with the bulb dusters that were mentioned earlier.

And unlike the liquid form, it works quite well on wasps of all kinds. It also lasts for up to 7 or 8 months and doesn’t dissolve in water. This makes it perfect for outdoor use.

Fill the bulb duster about half full of dust, then put a nickel or a small marble in there to help break up the clumps that form in it. Shake it vigorously, immediately put the tip next to whatever crack or crevice you want to treat and squeeze gently.

We also call these puffer dusters because that’s what you want – a small puff of dust going into the cracks. If you squeeze too hard a big cloud of it will blow back into your eyes, nose, and mouth.


Because you have to be so gentle with it, we only recommend using this outside, in attics, or beneath pier-and-beam houses.

In attics, you can squeeze out huge clouds of dust to settle over everything, especially spider webs and wasp nests. The same thing holds true under houses as well.

Around the outside, use it along the edges of windows and doors, around dryer vents, plumbing intrusions, A/C pipes, electrical intrusions, and others. As mentioned earlier, it’s good in hedges.

You can also stand upwind of spider webs and puff a cloud of it all over the web. Gets ’em every time.

The Good:

  • Very fast knockdown
  • Good active ingredient
  • Doesn’t dissolve in water
  • Long residual effect of 7-8 months

The Bad:

  • Difficult to control sometimes
  • Dust clouds come back in your face


  • 2,000 sq.ft. coverage
  • Broad spectrum insecticide
  • Very fast knockdown

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What Sprayers Should be Used to Kill Spiders?

There are four main kinds of equipment that professionals use when spraying for spiders along with one additional piece that is sometimes used as a supplement to the rest.

We’ll examine each one in turn. They are tank sprayers, backpack sprayers, handheld sprayers, bulb dusters, and granule spreaders.

When using any of this equipment, always wear a long-sleeved shirt and disposable latex gloves. A wide-brimmed hat is an excellent addition when you’re spraying overhead because there will be drift coming down on you. Guaranteed.

Tank Sprayers

There are several kinds of tank sprayers available on the market today for outside spraying.

There are the big professional tank sprayers that pest control professionals use, which cost several thousand dollars.There are also smaller versions intended for homeowners, which are much, much cheaper.

In either case, they are relatively easy to use. You fill the tank about half full of water, add the correct amount of concentrated pesticide according to the mixing instructions on the label, then agitate the tank while you finish filling it.

Once the tank is full, you can begin spraying the eaves of your house, around the doors and windows, and the foundation all the way around it.

After that, begin spraying outward from the house (or other building) in an expanding spiral, making sure you overlap the previous spiral slightly on each pass to ensure complete coverage.

How much you’ll spray will depend on the pesticide you’re using, but as a general rule, a 10×10 square foot area should take about 1/4-gallon of finished product. Read the label carefully on the pesticide you’re using for exact details on area coverage.

Backpack Sprayers

As the name implies, this is a sprayer with shoulder straps that you can easily carry on your back. Backpack sprayers usually hold 3-4 gallons of water.

Hint: water weighs 8.3 pounds per gallon, so we’re talking about 25-33 pounds on your back, plus the weight of the sprayer itself.

Backpack sprayers usually have a handle on one side for pumping up the pressure in the tank, along with a long hose and wand for outside spraying up high on eaves, over doorways, etc.

They’re also very useful for spraying tall hedges, windows, and rose bushes. Rose bushes, with their terrible thorns, are the bane of every bug man’s existence. Long wands make it easier to spray them without getting snagged.

The method of filling and mixing a backpack sprayer is the same with the standard tank sprayer. Fill the tank half full of water, add the correct amount of pesticide, agitate the tank, and finish filling it.

Once it’s full, put the lid and agitate it vigorously for another minute or so to thoroughly mix the chemicals and the water.

You can use a backpack sprayer to treat the yard, but it’s a long job requiring multiple refills. Eventually, all that weight on your back will start to feel like a thousand tons.

Unless you don’t have any choice, reserve the backpack for right around the house, and the tank sprayer for the yard.

Handheld (Pump) Sprayers

For inside work, most professional pest control technicians use a handheld stainless steel sprayer from the B&G company. In fact, we usually just refer to them as a B&G, equating the manufacturer’s name with the product.

B&G’s are so tough that when we accidentally ran over one when it fell off the back of our work truck one time, it didn’t even get a scratch! We kept on using it for years after that.

Sprayers for most home users are considerably cheaper than a B&G. They’re normally made of plastic, which means they can’t hold as much pressure as a B&G, or spray as far.

The lighter pressure also means the individual droplets exiting from the tip of the wand will be fairly large, in turn meaning you’ll be using more chemical in the process.

The filling and mixing procedures for handheld sprayers is the same with the tank and backpack sprayers.

You can use them to spray around baseboards, up in the corners of rooms, around windows and doors, behind refrigerators, washing machines, dryers, hot water heaters, under and behind beds and other furniture, and beneath sinks.

Bulb Dusters

These bulb dusters are a valuable addition to your spider killing arsenal. You can use them to treat cracks and crevices around doors and windows with pesticides that are formulated as dry dusts.

Because you can put the tip directly up against cracks and crevices, you can squirt a puff of dust straight into them where liquid sprays might not be able to penetrate.

Bulb dusts really come in handy when treating inside heavy shrubbery. Squat down low, put your arm as far inside the shrub or hedge as you can, then, aiming the nozzle of the duster up, squeeze it sharply several times.

You’ll send a cloud of dust floating up inside the bushes where most liquid sprays simply can’t penetrate. Repeat this procedure every 4-5 feet along the length of the bushes or shrubs.

Granule Spreaders

The last piece of equipment you might want to use is a granule spreader. This equipment is reliable when you’re spreading granules around the yard.

Granules have the distinction of being water activated, so if you’re trying to kill spiders outside during the rainy months of the year when liquid pesticides would be washed away, this is a very good alternative treatment.

We’ve used this successfully on many occasions with pleasant results. It doesn’t work as long or as quickly as liquid treatments, but anything is better than nothing.

Why Are Spiders In My Yard?

Now that you’re ready for war with the spiders, you might want to know why there are so many of them in your yard. Maybe there’s some way of keeping them out.

Like they say in the Starkist commercials, “Sorry, Charlie.”

The spiders will never stop coming. You can keep them down to a dull roar, but you’ll never eliminate them completely. There are two main reasons for this.

Baby spiders float

The first reason is that when spiders hatch, they’re so lightweight they can throw out a line of silk and get picked up by the faintest breeze.

Then they can float for miles before being randomly deposited wherever the wind took them. You can’t stop the wind, or the spiders it carries, so your yard will never be 100% free of spiders.

“Mi casa Su casa“

Spiders firmly believe in Mi Casa Su Casa – my house is your house, only in reverse, that your house is theirs as well.

If you live in a house that’s less than five years old, the chances are that the contractors had to knockdown trees and bushes to clear the property for construction. Those trees and bushes held thousands of spiders, who are now homeless and looking for somewhere to live; i.e., your house.

What is the Best Insecticide for Outdoor Spiders?

The best spider killer for outdoors and in the yard is a pesticide that has good sticking power and a long-term residual effect.

It needs to be one that can resist breaking down because of the sun, rain, wind, and other environmental stresses. Because it’s outside, you can use a stronger, more pungent pesticide than you would indoors.

Pesticides are heavily regulated by the EPA. They have been mandated by law that most pesticides must be bio-degraded down to zero within 90-days of their application.

Some pesticides are allowed to remain in place longer than that (mainly termiticides) but as a general rule, most pesticides are required to be gone by the end of 3 months.

This is why most pest control professionals recommend quarterly treatments for their customers. This means you’ll need to re-spray your property, inside and out, once every quarter or every 3 months.

What is the Best Indoor Spider Spray?

Indoor pesticides should have little or no smell to them. While the pesticides are safe for use around human beings, some of the older ones have strong odors which can cause sneezing or other nasal irritation.

Some of them can leave a bad taste in your mouth just from smelling them. Obviously, you don’t want to spray those in your house.

Wettable powders should probably be avoided inside. When they dry, they can leave a white residue on the walls.

This was first noticed in a wettable powder called Demon WP (Wettable Powder), which gave rise in the pest control industry to the phrase “demon tracks” to describe the visible residue it left behind.

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