Cyper WSP and Demon WP are the same product in every way that matters. They share the same active ingredient (40% cypermethrin), the same wettable powder formulation, and the same water-soluble packet delivery. The only real differences are the manufacturer and the price: Demon WP is the original name brand made by Syngenta, while Cyper WSP is a generic version made by Control Solutions Inc. at roughly half the cost.
Same Active Ingredient, Same Concentration
Both products contain 40% cypermethrin, a synthetic pyrethroid that attacks the nervous system of insects on contact and through ingestion. The remaining 60% consists of inert ingredients that help the powder dissolve and disperse in water. The cypermethrin in both products uses the same cis/trans isomer ratio (a maximum of 55% cis and minimum of 45% trans), which determines how the molecule behaves once applied. In practical terms, you get identical insecticidal performance from either product.
What They Kill and How Long They Last
Cypermethrin wettable powders provide both a fast knockdown effect and residual protection on treated surfaces. The list of target pests is broad: roaches, ants, spiders, scorpions, crickets, silverfish, flies, mosquitoes, wasps, and dozens of other crawling and flying insects. Both products work well for indoor crack-and-crevice treatments, perimeter sprays around foundations, and outdoor surface applications.
Residual control typically lasts several weeks to a few months depending on where you apply it. Indoor surfaces that stay dry and out of direct sunlight hold the residue longest. Outdoor applications break down faster from rain, UV exposure, and wind. Cypermethrin shows good persistence on most surfaces at standard application rates, though porous materials like untreated wood or concrete may absorb more product and reduce surface availability over time. Wettable powders generally leave a visible white residue, which is part of what makes them effective: the powder particles sit on the surface longer than liquid concentrates, extending the kill time.
Mixing Rates and Coverage
Both products come in pre-measured water-soluble packets, so you drop the entire packet into water without opening it. The standard mixing rate is one to two packets per gallon of water, depending on the pest and severity of the infestation. One packet is enough for lighter problems; two packets per gallon is appropriate for heavier pressure or harder-to-kill pests like scorpions or large roach populations.
Coverage depends on how you dilute it. For outdoor perimeter treatments, one to two packets mixed into one to five gallons of water covers up to 1,600 square feet. For general surface sprays outdoors, one packet per gallon treats roughly 1,000 square feet. Indoor applications use less volume since you’re targeting cracks, crevices, and baseboards rather than broad surfaces. Always shake the sprayer periodically during use, as wettable powders tend to settle.
Price and Availability
This is where the two products genuinely diverge. Demon WP, as the original name-brand product from Syngenta, carries a premium price. Cyper WSP from Control Solutions typically costs about half as much for the same quantity of packets. Both are widely available through online pest control retailers, and both are sold in envelopes containing multiple packets or in larger tubs for high-volume users.
Because the formulations are functionally identical, the price gap is purely a brand markup. Pest control professionals frequently use whichever is cheaper or more readily available from their distributor. For homeowners buying a single envelope, the savings may only amount to a few dollars, but if you’re treating regularly or covering a large property, the difference adds up.
Safety and Handling
Cypermethrin wettable powders carry a “Caution” signal word, the lowest toxicity category on the EPA’s scale. That said, the powder form demands respect during mixing. Full protective equipment is recommended when handling: long sleeves and pants (ideally coveralls), chemical-resistant gloves, protective eyewear, and closed-toe shoes with socks. A respirator is advisable when mixing the powder, particularly indoors or in poorly ventilated spaces.
Once the spray has fully dried on treated surfaces, the risk to people and pets drops significantly. The general guideline is to keep everyone out of treated areas until the application has dried completely. For agricultural or commercial settings, formal re-entry intervals of 48 to 72 hours may apply. In residential use, most labels instruct you to wait until surfaces are dry to the touch before allowing people and pets back into the area. Avoid applying where cats spend extended time on treated surfaces, as cats metabolize pyrethroids more slowly than dogs or humans.
Which One Should You Buy
If performance is your only concern, it doesn’t matter. Both products deliver the same concentration of the same active ingredient in the same formulation type. Cyper WSP is the better value for most buyers simply because it costs less. Demon WP has stronger brand recognition in the professional pest control industry, but that recognition doesn’t translate into better results on your baseboards or around your foundation. Pick whichever is cheaper or more readily available, and you’ll get identical pest control.