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Demon WP Insecticide

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Demon WP Insecticide

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Demon WP Insecticide kills large roaches, spiders, crickets and more. Demon WP Insecticide has been a number one seller for many years due to it's convenience of use. Simply drop the packets in the envelope in water (they dissolve). Demon WP Insecticide contains cypermethrin 40% and works well for a variety of insects, lasting up to 3 months.
Demon  WP - Envelopes

Demon WP - 1 Envelope - 0.3 oz (9.5 grams) packets

  • Buy 2 for $8.45 each and save 23%
  • Buy 12 for $7.95 each and save 28%


Demon WP Insecticide

Demon WP Insecticide, with cypermethrin 40.0% kills large roaches, spiders, crickets and more. It can be used inside or outside. Demon WP Insecticide in its envelopes has been a number one seller for many years due to it's convenience of use. Simply drop the packets in the envelope in water (they dissolve). Demon WP Insecticide works well for a variety of insects, lasting up to 3 months. A gallon of finished of Demon WP mix usually completely covers a 2,000 to 2,500 sq. foot home.

  • Demon WP 1 lb tub has been discontinued by the manufacturer.
  • Cyper WSP ( packets) have the same label as Demon WP, but are more economical.

Demon WP and Cyper WSP are classified as a long-term residuals. Demon WP and Cyper WSP may be used inside and outside. They are authorized by the USDA for use in inedible product areas in federally inspected meat, poultry and egg processing plants. They will last 2 to 3 months as a sprayed residue, however, use all that you mix in your sprayer. As with most insecticide concentrates, they will not hold up in a water solution.

Demon WP and Roaches

For the small German Roaches, choose a high quality roach bait like Maxforce Impact Roach Bait or Invict Roach Gel . German Roaches have grown immune to most insecticides like Demon WP.

Childen and Pet Safe ?

Yes, when used as directed. Keep off of wet surface until they dry.

Additional Information

Additional Information

Pro Tips Demon WP packs are easy to use, just mix them into water. Mix well in your sprayer, and use the finished solution within a couple of days. Demon was a good German Roach killer, but they seem resistant to it now. Gel and powder baits are the best choices for the German Roach.

Cyper WSP ( packets) have the same label as Demon WP but are more economical. Both Demon WP and Cyper WSP are classified as a long-term residual insecticides.
Packaging envelopes, each envelope contains 4 x 0.3 oz (9.5 grams) packets
Manufacturer Syngenta
Product Label Label
Target Pest ants, boxelder bugs,carpenter ants, centipedes,cockroaches, crickets,firebrats, millipedes,silverfish,scorpions,spiders,wasps and certain other insect pests.
Active Ingredient (s) Cypermethrin 40.0%
For Use : For you in an around buildings and structures for listed pests.Residential, institutional, public, commerical, agricultural and industrial buildings
Yield One envelope of Demon WP yields 2-4 gallons | 1 lb of Demon WP yields 24-48 gallons
Mixture|Application N/A

A general surface, crack and crevice and/or spot treatment for residual control. Use between 1-2 packets (Envelopes) or 1-2 scoops(Tubs) per gallon of water for a concentration of 0.1%-0.2% of active ingredient. Demon WP leaves a white powdery film that is especially noticeable on dark surfaces.Use D-Fense SC Insecticide too avoid visible residues

Retreatment Every 2-3 months, more often during heavy rainfall
Shipping Restrictions CT, NY
A suggested alternative would be Fenvastar Cap
More Instructions

Demon WP leaves a white powdery film that is especially noticeable on dark surfaces.Use D-Fense SC Insecticidetoo avoid visible residues.

We sell only professional pest control products. Demon WP Insecticide is not available in home improvement centers or hardware stores such as Home Depot, Lowes, or Ace Hardware.

An another product called: * Cyper WP has the exact same label, but is less expensive than Demon WP.

Demon WP and Cyper WP are extremely toxic to fish. Do not apply directly to water or to areas where surface water is present or to intertidal areas below the mean high water mark. Wet liquid contact with skin may result in transient tingling and reddening of the skin. Remove contaminated clothing and wash before reuse. Always have dependable equipment to avoid leakage.


Customer Reviews 48 item(s)

Very satisfied!
Great product! It even kills pesky ants in mounds around the yard! Ordering is easy and reliable. Customer service is excellent for questions regarding products. Also great for spraying around your porch for wasps. It continues to work for months. Wasps don't go near an area that has been sprayed, and if they land on that area, they soon die.
Review by The Terminator / (Posted on 10/9/2015)
used it once 2 years ago and now....
used this stuff once 2 years ago for a infestation of roaches. I also combined it with a IGR and a gel bait. Well now it is 2 years after and I have not seen a bug in FOREVER....well we are about to move so I had to order some more for the new house just in case. Great product and I am just ready for my next shipment.
Review by erica / (Posted on 9/17/2015)
have used for years always woks great
Review by art / (Posted on 8/8/2015)
Texas Cricket Massacre
Infestation of small crickets in vacant lot next to my business; they were invading nightly causing havoc to my customers. Sprayed a 1 foot band on a curb between me and the vacant lot and next morning there was a carpet of dead crickets measuring 10 ft x 40 ft. Residual effect kept killing and now no cricket problem. Demon- aptly named- and thank you!
Review by Buck / (Posted on 7/29/2015)
Great item
Well went on to doing my second treatment of Demon WP. This product is by far really effective. First started with the two packets in one gallon. I had a scorpion proplem in my new home. These things were just about everywhere. Ever since my first treatment i have yet to see one! I've went around doing the second treatment and its once again great! I does leave a white residue behind so becareful of furniture or items you don't want sprayed!!! All in all well worth it!
Review by Rene / (Posted on 7/8/2015)
cost effective beneficial insecticide
Very useful comprehensive insecticide for indoor and outdoor use. Long lasting effect indoors. Particularly effective against roaches.
Review by Summary / (Posted on 7/4/2015)
We've been using Demon WP for all of our bug problems both in the South and now the Midwest. We've been using it for well over ten years. It is the best out there! If you are like me, I don't like to see bugs in my house, use this product. No need to pay for pest control services when you can do it yourself. And it works much better and lasts longer than what they use.
Review by Lee Ann / (Posted on 6/30/2015)
Excellent and Easy
Demon WP was just what the doctor ordered! Have not seen a scorpion since we sprayed. Thanks so much.
Review by WOW / (Posted on 6/27/2015)
Excellent product
Over the past 17 years we have been fighting box elder bugs and Asian lady beetles among a variety of other random insects that like to frequent our 145 year old home. Last year a colony of carpenter ants took up residence in a 200+ yr old maple tree and soon expanded to other trees and our home. We have tried everything to win this insect battle and after ordering and applying Demon WP we only saw one bee in our attic window. We consider this a miracle, if we had only known about Demon years ago it would have saved us many hours of grief and a lot of wasted money. Thank you.
Review by Kathleen / (Posted on 6/8/2015)
demon wp A+
long story short
we decided to move north to western maine .
after moving in we had a problem with those Japanese lady bugs
and also cluster flies, went to the box stores we bought and tried several things which to be honest had no affect.
after doing some research online we decided to buy demon wp.
all I can say is incredible! those Japanese lady bugs are no longer
and cluster flies is reduced 90% this stuff really works when applied
as directed. I sprayed around the foundation, all my eves and around the roof line.
worth every penny in my book great product.
Review by turbocoupe / (Posted on 5/11/2015)
Great product I reecomend it.
Have been using this for a few years for ants really gets rid of them I would recommend it for anyone to use.
Review by Faithie / (Posted on 5/11/2015)
Great stuff!
I have been using this product for years. It does a great job and saves us a bundle on exterminator costs.
Review by Burt / (Posted on 2/4/2015)
Great product
Fast delivery
Review by Judi / (Posted on 11/15/2014)
very satisfied
Easy to use and effective.
Review by mp / (Posted on 11/4/2014)
comment on purchase of Demon
Demon is the best bug, fly, crawl killer I have ever used. We live in Florida and we have bugs that that have ten legs 8 wings and many
more . Demon will kill them.The best!
Review by johnnie / (Posted on 10/31/2014)
5 star
Great product for ant and spider control. Convenient and easy to use!
Review by efort / (Posted on 10/24/2014)
Best stuff out there
I've been using Demon for years and it works! I don't use anything else.
Review by Phill / (Posted on 10/21/2014)
excellent product
Works like a charm. I have used it for years and love this product. keeps away the Japanese beatles
Review by codger / (Posted on 10/18/2014)
great product i highly recomend demon wp!
best product that I have ever used, for years we were plagued with the big oriental cockroaches but since the first application ive seen only dead bugs belly up and less to virtually no more of these bugs dead or alive
Review by mike / (Posted on 7/26/2014)
Demon is the best
Been using Demon for over 30 yrs. Still the best stuff I've ever used.
Review by John / (Posted on 6/18/2014)
Well pleased with product.
We have used this product for years and are very happy with the results. Only bugs we see are DEAD ones.
Review by BLT / (Posted on 6/16/2014)
So so
I have no fleas spiders, roaches, wasps , but has not worked as well as I was hoping for the fire ants, that are a major re occurring problem on the lawn, front and back, I think I will try a new product

DIY RESPONSE: Demon can be used on Fire Ants, however you have to apply it using the drench method. If this doesn't work acephate products work well against fire ants: http://store.doyourownpestcontrol.com/active-ingredients/acephate-insecticide-products

Fire Ants (Mounds):
For individual fire ant mounds, apply DEMON WP as a
drench. Gently sprinkle (watering can) a total of 1 gallon over the surface
of mounds up to 12 inches in diameter and 2 gallons for larger mounds.
Thoroughly wet mound and surrounding area. Treat new mounds as they
appear. Pressurized sprays may disturb the ants and cause migration. If
possible, applications should be made on warm days after recent rainfall. All
colonies in the vicinity should be treated, including those that have not yet
constructed a mound.
Review by Puccinismum / (Posted on 6/10/2014)
Demon Gets the Job Done Right
Been using on a friend's recommendation, when I had a problem with roaches. I remembered a friend never had a problem and also used on his mother's home, that I had been to many times, so I asked what he used. Now, my brother, sister and a friend wouldn't use anything else. My brother lives in Florida, always had a problem with the large roaches flying in from outside, and I was afraid to stay there. After I sprayed his house inside and out, the only roach you will ever see, if any, is a dead one. Yea Demon!
Review by Donna / (Posted on 5/26/2014)
Half bug will travel
Bugs come out from hiding and die. This product is very good for that.

Prompt delivery by Do-it-Yourself is great.
Review by pacaarmijo / (Posted on 3/25/2014)
good product
We have used Demon WP for years and would encourage anyone to use it as a self pest control product.
Review by Chickadee / (Posted on 10/26/2013)
Bugs are running scared
I finished application of 1 gallon of Demon WP a few minutes ago and the giant nasty american cockroaches that plague Georgia are running away from the house in droves. I have a cedar sided home with a partial crawlspace and the roaches have been horrible this year. I'm finding the twitching little b@$t@rds all over the basement and outside in the pinestraw. I will definitely buy Demon WP again. I was very pleased and surprised to find the little $10 pack I purchased contained multiple application packets as I was expecting only enough for one application. DIYPC shipped my purchase the same day and it arrived within 48 hours! Awesome product, Awesome Customer Service!
Review by aric / (Posted on 8/10/2013)
Still Killing the bugs
Been using this stuff for years. Works great, easy to mix
Review by Bruce / (Posted on 8/7/2013)
Beyond Awesome
When we moved into our new farm house we quickly discovered that we had a big wasp problem. I mean we had thousands of them.

We tried everything without success and finally we stumbled across Demon WP. Not only did it take care of the wasps in kills but also spiders, ants, you name it.
Review by Scott in SC / (Posted on 8/5/2013)
More effective than home depot sprays
I had a gallon of the home defense bug spray and used it two weeks ago. Saw some dead roaches around. Tried this on a friends recommendation and had triple the roaches on their backs. Will have to wait to see how long it lasts. The other raters make me hopeful.
Review by Tim / (Posted on 7/21/2013)
Best Stuff
My dad 20 years ago told us to get Demon wp to kill the scorpions in our garage when we moved in our first new home together. We've used this stuff literally around our house, not inside, just outside around the perimeter of the home and we never have any bugs of any kind to deal with, EVER. Use it and you will be hooked on the quality and dependability of it.
Review by Toodles / (Posted on 5/28/2013)
Great Stuff
Sprayed this around our house 2 months ago and have had no Scorpions in our house. Use to have dozens every year.
Review by Eddy / (Posted on 5/4/2013)
Used it for over 25 years
I started using this back in the 80's I was working in the pest control field when I first started using it and used it for just about everything from one time treatments to monthly treatments. It worked great on every type of insect from flying to crawling.
I would recommend that you swap up every few years in Pesticides to make sure the insects in your area do not get immune to any specific type.
This product does leave a slightly off white residue on wood floors and trim. The odor is very slight and only lasts for a day or so. Still its a lot better than oil base pesticides.
It doesn't work for German roaches, however.
Review by James / (Posted on 4/19/2013)
Demon works great
I have been using Demon for quite some time. it was first recondmended to me for an infestation of fleas. It worked great indoors and outdoors but if using indoors it does leave a residue.
It is a great product and affordable. If you have pets be sure to let it dry before letting your pets walk in the treated area
Review by Rick / (Posted on 2/26/2013)
Works really well
I was introduced to this product by a friend. I was having an issue with american cockroaches. The roaches were seen scurring across the baseboards and even climbing the walls. I sprayed as directed all around my house, the next morning I woke and there were over 10 large dead bugs. Slowly over the next few days I upon waking I noticed less and less dead bugs. Now, I use the product as maintenance. It has almost eliminated my infestation. I also use it to exterminate fire ant mounds that appear in my yard, I just take the sprayer and soak the mound, it's almost an instant kill for the whole nest. Works well on spiders, too!
Review by Justin / (Posted on 10/20/2012)
Finally found something that works on Box Elder Beetles
Tried a number of products but have never found anything that works as well as Demon WP on BOX ELDER BUGS.
Spray the ground under where you see the Box Elders in the Fall and they will not come back the following year
Review by Duke / (Posted on 9/29/2012)
First Time User
I used this product on a black widow infestation. Mixed using the instructions on the package for killing spiders, sprayed on a Saturday, went back under the house on Wednesday and everything under the house was dead. Only gripe is the white residue.
Review by Brad / (Posted on 8/14/2012)
Super product
I have been using Demon WP for several years now. I spray my outdoor balcony for hornets, and spray inside for centipedes. I haven't seen bugs in years. Yeah!!!
Review by Debbie / (Posted on 7/28/2012)
best ever
For years i have had spiders on the north side of my house and have tried everything. Had to wash house every two weeks. Sprayed once and have not had spiders for two years. Think i will spray again but i am not sure why.
Review by boots / (Posted on 7/14/2012)
Out standing product
I have use the product in the past and I am very, very happy to have tried it and very happy to say that it is a out standing product.
Review by Veronica / (Posted on 7/11/2012)
I were introduced to this at an local garden center. I have been using this for a week this is a great product.
Review by Leroy / (Posted on 6/29/2012)
Works great
Have been using this product for years, works great and I save a bundle not using an exterminator.
Review by Steve-0 / (Posted on 5/28/2012)
tried demon
I read on the website to use this product for German roaches and was quite ready to be rid of my "new roommates." This did nothing to them. It killed the babies that were so tiny you could barely tell it was a dead bug but had no effect on any others. Works well on the ant piles in the yard though and as a preventative for other bugs around the home. Completely useless on my roach problem though. I just ordered a bait called invirt and I'm hoping that will kill them.
Review by Lindsay / (Posted on 5/28/2012)
This stuff kills all the creepy crawlies!
Nothing harder to kill than brown recluse spiders. You can read why on your own. I captured a brown recluse spider in my outdoor garage and put it in a baby food jar after spraying some of this in the jar. 15 minutes later it was dead.
This stuff also kills everything else in the state of Alabama bug wise.
Love it!
Review by CyberHuie / (Posted on 5/19/2012)
no bugs
This stuff is FANTASTIC! I usually buy it at the feed store, but, our feed store closed down. I only have to buy it every two or so years, spray around the house and no bugs. It's been about two years so I got it here, cheaper, with free shipping.
Review by Nick / (Posted on 5/11/2012)
Not a bug in 3 years!
I battled ants in my kitchen and bathrooms and was beginning to see small roaches and an assortment of other pests in my garage. For three years now my house and garage have been bug free.

This product is virtually odorless, non-staining and very easy to use.

Unbelievably effective!

BUT do not get carried away and use it on your plants in the garden. I saw from the label that it could be used in the grass and no harm was done. It completely wiped out my beds of well established and previously healthy english ivy. (Not smart on my part!)
Review by Mom in Dallas / (Posted on 5/8/2012)
Best stuff I ever used
Used for carpenter ants and scorpions. Fantastic. Collateral action on other insects and spiders. Well worth the money.
Review by howardd / (Posted on 5/1/2012)
great product
I have been buying this product since the mid 90s and found it to work great. Friends and family that I introduced to it have agreed it is awesome.
Review by Misha / (Posted on 4/19/2012)
I have ordered Demon WP several times
I have ordered Demon WP several times in the last 10 years and am very satisfied with how it kills my spiders Do It Yourself Pest Control has helped me consistently. It last a long time and theprices are always good.
BM Review by Barb / (Posted on 3/5/2012)

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