Onslaught FastCap Spider and Scorpion Insecticide

Onslaught FastCap Spider and Scorpion Insecticide
Onslaught FastCap Spider and Scorpion Insecticide


Onslaught FastCap Spider and Scorpion Insecticide

Onslaught Fastcap Microencapsulated Insecticide is controlled release technology that provides long-lasting residual control of a broad spectrum of insects. Nothing is proven to work better on tough pests like bed bugs, spiders, and fleas.
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Quantity / Bulk
Pint ($3.74/ounce)
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Key Features:
  • Effective against bed bugs, spiders, scorpions, and more
  • Kills bed bugs on contact with a residual of up to 12 months
  • Low odor
  • Labeled for food and non-food areas

Bed Bug Supply Review - see what our experts have to say about this product

MGK has enhanced Onslaught’s fast-acting and long-lasting residual strength, for greater efficiency against a slightly narrower range of pests. They started with Onslaught’s active ingredient, esfenvalerate, a proven residual pyrethroid. Then, they added prallethrin for better control of flying insects, and mixed the two with Exponent for faster action and less resistance. The result is Onslaught FastCap, the residual of choice against spiders, scorpions, and more. It kills faster, lasts longer, and is more economical to use than its predecessor.

Similar to Onslaught, Onslaught FastCap has one of the most flexible labels in the industry. It is effective against over 170 insect species, and is labeled for food and non-food areas. Onslaught FastCap can be used as a broadcast or crack and crevice treatment, a perimeter spray, wall void injection, or in a tank mix. It can be sprayed on any surface that won’t be stained by water - to be sure, test the surface by spraying a small amount in an inconspicuous area.

To control bed bugs, we recommend using Onslaught FastCap as a spot treatment on places where bed bugs are likely to hide and travel. This includes headboards, floorboards, and where the walls meet the baseboard. Focus your spray on cracks and crevices to ensure that they get filled with the mixture.

Product Information

Onslaught Fastcap is a microencapsulated residual insecticide. What that means is that the chemicals are encapsulated, and slowly release over time. That slow release allows for an incredibly effective residual protection. Onslaught Fastcap's flexible label allows for use against a broad range of tough pests, like bed bugs, roaches, scorpions, spiters, and more.

For use against bed bugs, start by thoroughly cleaning and sanitizing the mattress and box spring, and treating them first with a contact killer. Then, apply Onslaught Fastcap as a spot treatment to cracks and crevices around baseboards, floorboards, headboards, and wall voids.

Treating for mosquitoes / Zika virus prevention:

Onslaught Fastcap is quickly becoming the premier option for mosquito control to help combat the current Zika epidemic. Pest control operators that are experienced in mosquito elimination and prevention recommend using NyGuard IGR in a tank mix with Onslaught Fastcap. NyGuard mimics juvenile hormones to effectively break the reproductive cycle of mosquitoes and other pests.

To combine NyGuard and Onslaught Fastcap in a pump sprayer, mix 4 mL of NyGuard with 4 mL of Onslaught Fastcap per 1 gallon of water. This will give you a combination of knockdown, residual kill, and residual growth regulation for up to 1,000 square feet of treated space.

Onslaught Fastcap Microencapsulated Bed Bug Spray

Insects Controlled:

  • Alfalfa Caterpillars
  • American Plum Borers
  • Angoumois Grain Moths
  • Annual Bluegrass Weevils
  • Ants
  • Aphids
  • Apple Maggots
  • Armyworms
  • Artichoke Plum Moth
  • Asian Lady Beetles
  • Bagworms
  • Balsam Woolly Adelgids
  • Bed Bugs
  • Bees
  • Beet Armyworms
  • Beetles
  • Billbugs
  • Biting Flies
  • Blow Flies
  • Blueberry Spanworms
  • Boxelder Bugs
  • Brown Marmorated
  • Brown Marmorated Stink
  • Bugs
  • Cadelles
  • Carpenter Ants
  • Carpenter Bees
  • Carpet Beetles
  • Cherry Fruit Flies
  • Cherry Fruitworms
  • Chiggers
  • Chinch Bugs
  • Cigarette Beetles
  • Clothes Moths
  • Cockroaches
  • Codling Moths
  • Confused Flour Beetles
  • Cowpea Curculios
  • Cranberry Fruitworms
  • Cranberry Weevils
  • Crane Flies
  • Crickets
  • Cucumber Beetles
  • Cutworms
  • Dark Mealworms
  • Deathwatch Beetles
  • Deer Flies
  • Deer Ticks
  • Diamondback Moths
  • Dog Ticks
  • Dried Fruit Beetles
  • Drugstore Beetles
  • Earwigs
  • Elm Leaf Beetles
  • European Pine Sawflies
  • Face Flies
  • Fall Webworms
  • Filbert Worms
  • Fire Ants
  • Firebrats
  • Flat Grain Beetles
  • Flea Beetles
  • Fleas
  • Fruit Flies
  • Fungus Gnats
  • Furniture Beetles
  • Gnats
  • Grain Mites
  • Grain Moths
  • Granary Weevils
  • Grasshoppers
  • Green Cloverworms
  • Green Fruitworms
  • Gypsy Moth Caterpillars
  • Hickory Shuckworms
  • Horn Flies
  • Hornets
  • Houseflies
  • Imported Cabbageworms
  • Indian Meal Moths
  • Japanese Beetles
  • Lace Bugs
  • Leaf Feeding Caterpillars
  • Leaf Miners
  • Leaf Rollers
  • Leaf Tiers
  • Leafhoppers
  • Lesser Appleworms
  • Lesser Grain Borers
  • Lesser Peach Tree Borers
  • Lice
  • Loopers
  • Lygus Bugs
  • Maize Weevils
  • Meal Moth Larvae
  • Mealy Bugs
  • Mediterranean Flour Moths
  • Merchant Grain Beetles
  • Mexican Bean Beetles
  • Midges
  • Millipedes
  • Mites
  • Mole Crickets
  • Mosquitoes
  • Naval Orangeworms
  • Northern Pine Weevils
  • Old House Borers
  • Oriental Fruit Moths
  • Painted Lady Caterpillars
  • Pea Weevils
  • Peach Tree Borers
  • Peach Twig Borers
  • Pear Psyllid
  • Pear Slugs
  • Pecan Leaf Phylloxera
  • Pecan Nut Casebearers
  • Pecan Spittlebugs
  • Pecan Stem Phylloxera
  • Pecan Weevils
  • Pepper Weevils
  • Periodical Cicadas
  • Pickleworms
  • Pillbugs
  • Pine Chafers
  • Pine Coreid Bugs
  • Plant Bugs
  • Plum Curculios
  • Powder Post Beetles
  • Psocids
  • Red Flour Beetles
  • Red Pine Sawflies
  • Red-headed Pine Sawflies
  • Red-striped Fireworms
  • Rice Weevils
  • Rindworms
  • Round-headed House Borers
  • Rusty Grain Beetles
  • Salt Marsh Caterpillars
  • Sap Beetles
  • Saw-toothed Grain Beetles
  • Scales
  • Scorpions
  • Silverfish
  • Skippers
  • Small Flying Moths
  • Sod Webworms
  • Sowbugs
  • Spider Beetles
  • Spider Mites
  • Spiders
  • Spittlebugs
  • Springtails
  • Square-necked Grain Beetles
  • Stink Bugs
  • Stinkbug
  • Swarming Termites
  • Tarnished Plant Bugs
  • Tent Caterpillars
  • Thrips
  • Ticks
  • Tobacco Hornworms
  • Tobacco Moths
  • Tufted Apple Bud Moths
  • Velvet Bean Caterpillars
  • Walnut Husk Flies
  • Wasps
  • Waterbug
  • Western Bean Cutworms
  • Whiteflies
  • Yellow Jackets
  • Yellow Mealworm

Questions and Answers

Q: About how long will fastcap last on outside for spider control? And is this the best that you carry for outside spider control or should I use something you can rec?
Asked by: Dave - 1/22/2014
Onslaught FastCap will last for up to 12 months, depending on the weather and sunlight that it's exposed to. We only specialize in bed bugs here at Bed Bug Supply, so we can't make any recommendations on what to use against spiders.
Q: What is the active ingredient in this pesticide?
Asked by: Meet - 9/30/2018
This is a multi-action compound. The active ingredients are esfenvalerate and prallethrin.
Q: Does this get rid of lady bugs?
Asked by: Linda - 2/27/2020
This product is labeled for use against Asian lady beetles, which are similar but not identical to common lady bugs. Use against a species that the product isn't labeled for is not advised.

Customer Reviews

Write a Review View All Reviews
5/ 5stars
The fascap product worked better than everything else we tried. it kept our issues at bay for 7 days to sometimes only 3 days--but 3 full nights' sleep without "issues" is a significant progress. Not only that, but the price was better than anything else we have tried. Still not positive what we have--but to have ANY relief is H U G E !!! THANK YOU.
Reviewed by:  from ohio.
5/ 5stars
onslaught review
Best price and fast shipping great combo thanks!!
Reviewed by:  from Reseda.
5/ 5stars
Great product... works as it says it does
Reviewed by:  from Milford.
5/ 5stars
I purchased the spray mainly because of the scorpions we have in the SW. We had noticed a couple in the house and after an internet search the Onslaught FastCap seemed to be recommended quite frequently. A product search brought up your site, among others, and when ordering online I do like to use PayPal. I also appreciated the 2 business day delivery. The package arrived in excellent condition and I would most definitely order from B B Supply again. I haven't seen any dead scorpions laying around yet, but then I haven't seen any live ones either. Jim Petersen Las Cruces, NM
Reviewed by:  from las cruces, nm.