Gain access to personalized product screening, the best pricing, rewards, and more!
Create An Account, Or Sign In.
Your Product Analysis:
Home
Grass
Property
Kids or Pets
You Need:
$5.00
For your -- home1
Your Cost:
Your Cost:
$5.00
Price per
application2
application2
MGK
Onslaught FastCap Insecticide
Onslaught FastCap Insecticide is a microencapsulated insecticide concentrate that delivers fast-acting and long-lasting residual control of spiders, scorpions, and a broad spectrum of other common household insects. It is easy to mix and apply.
As low as
$65.05
Only %1 left
SKU
Onslaught FastCap Insecticide
Min : 65.05 - Max : 418
+
Price as of
09/16/25
09/16/25
Price Transparency
See how our pricing compares to other online retailers for this item.
Onslaught FastCap Insecticide, manufactured by MGK, is a microcap insecticide with controlled-release technology for treating a wide range of common intruding pests.
This product's controlled release technology ensures long-term residual control, decreasing frequent applications. As a fast-kill and residual control insecticide, Onslaught FastCap Insecticide will control pests such as ants, aphids, and sod webworms.
Onslaught FastCap Insecticide is a fast-acting insecticide that contains a unique formulation to control indoor and outdoor pests within 7-14 days.
Tools Needed
You will need a hose-end sprayer, handheld pump sprayer, backpack sprayer, or spray rig. We recommend a handheld 1-gallon pump sprayer for small household jobs or a 4-gallon backpack sprayer.
How to Use
- Step 1: Insect control on lawns, turf grass, and turf will do well to be mowed at least 1 to 2 days prior to treatment. Determine how much Onslaught FastCap Insecticide to use by measuring the square footage of the treatment area. You can do this by measuring the treatment areas' length and width in feet, then multiplying them together (length X width = square footage). Depending on the target insect, Onslaught Fastcap Insecticide can be mixed from 0.5 to 1.0 fl. oz. per gallon of water to treat 1,000 sq. ft. So, for example, if you wanted to treat for fleas (0.5 fl. oz. rate) and calculated a 2,500 sq. ft. treatment area, you will need to mix 1.5 fl. oz. of Onslaught in three gallons of water.
- Step 2: Based on your calculations, fill your sprayer halfway with the required amount of water, then add the appropriate measured amount of Onslaught Fastcap Insecticide. Fill the sprayer with the remaining half of the water, close the top, and agitate the sprayer to mix the solution well. You are now ready to spray.
- Step 3: Apply the solution as a coarse, wet spray in the areas where pest infestations are present. Use it as a broadcast surface spray, crack and crevice treatment, spot treatment, or inject into wall voids.
- Step 4: Keep pets and people off of treated areas until dry. Onslaught should kill pests in 1-2 days and is still active for up to 90 days after application.
Where to Use
Onslaught FastCap Insecticide can be used inside homes, offices, and other man-made structures. It is also safe and effective outdoors on turf and livestock sites. Apply a band 10 feet wide around the perimeter and up to 3 feet high on a foundation and around windows, doors, and roof overhangs.
Indoors, you can apply a coarse, low-pressure spray to areas where these pests hide, such as baseboards, corners, storage areas, closets, around water pipes, doors and windows, attics, eaves, and behind appliances.
DO NOT allow spray to contact food or food-containing surfaces, feed, or water supplies.
When to Use
You should use Onslaught FastCap Insecticide when pest activity is high. For most areas of the country, this is between March and October. Depending on rain and pest pressure, you should spray every 30-90 days.
Safety Information
Onslaught FastCap Insecticide is safe to use around children and pets when applied according to the product label instructions. Always wear the appropriate personal protective equipment (PPE) when mixing or applying this product.
Remove pets and cover fish aquariums and pets' food and water dishes before spraying.
Do not permit humans or pets to contact treated surfaces until the spray has dried.
DO NOT SPRAY PETS WITH THIS PRODUCT.
Special Considerations
Onslaught FastCap Insecticide is a microencapsulated product concentrate that can settle out once diluted in water. Because of this, we recommend that anything you mix up be used on the same day. Continuously agitating the solution in a spray tank during treatment is also necessary.
| Availability | Online |
| Restricted Use | No |
| Shipping Restrictions | 1 Gallon: AK, CA, CT, HI, IN, MI, NY, OR, RI, SC, VT 16 Ounce: AK, CA, CT, HI, IN, MI, NY, OR, RI, SC, VT |
| Brand | MGK |
| Keith's Pro Tips | "Onslaught is a great broad-spectrum liquid insecticide if you want a professional quality treatment around the home. For indoor roach problems, you may need to use a gel bait like Apex Cockroach Bait to get full control. Make sure not to apply Onslaught where you have applied bait." |
| Product Drawbacks | Onslaught FastCap Insecticide can settle out once diluted in water so it will need to be constantly agitated during application so it can remain suspended. |
| Target Pests | 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 StinkBugs, Brown Marmorated Stinkbug, 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, Diamondback Moths, Dark Mealworms, Deathwatch Beetles, Deer Flies, Deer Ticks, 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, 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, and Yellow Mealworm. |
| Application Equipment | Backpack Sprayer, Pump Sprayer |
| Application Methods | Broadcast Spray, Crack & Crevice, Spot Treatment |
| Active Ingredient | Esfenvalerate 6.40%, Prallethrin 1.60%, and Piperonyl butoxide 8.00% |
| Product Type | Insecticide |
| Formulation | Microencapsulated |
| Application Rate | For general applications, use 0.5 oz. of Onslaught FastCap Insecticide per gallon of water per 1,000 sq. ft. Heavy infestations, apply 1.0 oz. of product per gallon of water per 1,000 sq. ft. |
| Shelf Life | Onslaught can last up to 3 years in storage when stored in a cool, dry area under lock and key. Store away from food, pet food, feed, seed, fertilizers, and veterinary supplies. Place liquid formulations on lower shelves and dry formulations above. |
| Yield | If Onslaught FastCap is used at the higher rate of use each pint size bottle will treat an estimated 16,000 square feet of surface. |
| Use Sites | Indoors, Outdoors |
| Time to Kill | Onslaught FastCap Insecticide provides immediate results but may take up to several treatments to gain full control of infestation depending on target pest. |
| Comparable Products | Cyzmic CS, Fenvastar EcoCap |
| EPA Registration # | 1021-2574 |
| Restricted Use | No |
|---|---|
| Shipping Restrictions | AK, CA, CT, HI, IN, MI, NY, OR, RI, SC, VT |
| Availability | Online |
| Signal Word | CAUTION |
| Keith's Pro Tip | "Onslaught is a great broad-spectrum liquid insecticide if you want a professional quality treatment around the home. For indoor roach problems, you may need to use a gel bait like Apex Cockroach Bait to get full control. Make sure not to apply Onslaught where you have applied bait." |
| Target Pests Multi | Red Pine Sawflies, Alfalfa Caterpillars, American Dog Ticks, American Plum Borers, Angoumois Grain Moths, Annual Bluegrass Weevil, Ants, Aphids, Apple Maggots, Armyworms, Artichoke Plum Moth, Asian Lady Beetle, Bagworms, Balsam Woolly Adelgids, Bed Bugs, Bees, Beet Armyworms, Beetles, Billbugs, Biting Flies, Blow Flies, Blueberry Spanworms, Boxelder Bugs, Cadelles, Carpenter Ants, Carpenter Bees, Carpet Beetles, Cherry Fruit Flies, Cherry Fruitworms, Chiggers/Red Bugs, 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, 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 Beetle, Fleas, Fruit Flies, Fungus Gnats, Furniture Beetles, Gnats, Grain Mites, Granary Weevils, Grasshoppers, Green Cloverworm, Green Fruitworms, Gypsy Moth Caterpillars, Hickory Shuckworms, Horn Flies, Hornets, House Flies, Imported Cabbageworms, Indianmeal Moths, Japanese Beetle, Lace Bugs, Leaf Feeding Caterpillars, Leafhoppers, Leafminers, Leafrollers, Leaftiers, Lesser Apple Worms, Lesser Grain Borers, Lesser Peach Tree Borer, Lice, Loopers, Lygus Bugs, Maize Weevils, Meal Moth Larvae, Mealybugs, Mediterranean Flour Moth, Merchant Grain Beetles, Mexican Bean Beetles, Midges, Millipedes, Mites, Mole Crickets, Mosquitoes, Moths, Navel Orangeworms, Northern Pine Weevils, Old House Borer Beetle, Oriental Fruit Moths, Painted Lady Caterpillars, Pea Weevils, Peach Tree Borers, Peach Twig Borer, Pear Psyllid, Pear_Slugs, Pecan Leaf Phylloxera, Pecan Nutcasebearers, Pecan Spittlebugs, Pecan Stem Phylloxera, Pecan Weevils, Pepper Weevils, Periodical Cicadas, Pickleworms, Pillbugs, Pine_Chafers, Pine_Coreid_Bugs, Plant Bugs, Plum Curculio, Powder Post Beetle, Psocids, Red Flour Beetles, Red-Headed Pine Sawflies, Redstriped Fireworms, Rice Weevils, Rindworms, Round-Headed House Borers, Rusty Grain Beetles, Salt Marsh Caterpillars, Sap Beetles, Saw-Tooth Grain Beetles, Scales, Scorpions, Silverfish, Skippers, Sod Webworms, Sowbugs, Spider Mites, Spiders, Spider_Beetles, Spittlebugs, Springtails, Square-Necked Grain Beetles, Stink Bugs, Swarming Alates Termites, Tarnished_Plant_Bugs, Tent Caterpillars, Thrips, Ticks, Tobacco Chocolate Moths, Tobacco Hornworms, Tufted Apple Bud Moths, Velvet Bean Caterpillars, Walnut Husk Flies, Wasps, Waterbugs, Western Beancutworms, Whiteflies, Yellow Jackets, Yellow Mealworms |
| Time to Kill | Onslaught FastCap Insecticide provides immediate results but may take up to several treatments to gain full control of infestation depending on target pest. |
| Chemical Type | Insecticide |
| Formulation | Microencapsulated |
| Application Methods | Broadcast Spray, Crack & Crevice, Spot Treatment |
| Product Drawbacks | Onslaught FastCap Insecticide can settle out once diluted in water so it will need to be constantly agitated during application so it can remain suspended. |
| Active Ingredient | Esfenvalerate 6.40%, Prallethrin 1.60%, and Piperonyl butoxide 8.00% |
| Application Equipment | Backpack Sprayer, Pump Sprayer |
| Mix Rate | For general applications, use 0.5 oz. of Onslaught FastCap Insecticide per gallon of water per 1,000 sq. ft. Heavy infestations, apply 1.0 oz. of product per gallon of water per 1,000 sq. ft. |
| Use Sites | Indoors, Outdoors |
| Yield | If Onslaught FastCap is used at the higher rate of use each pint size bottle will treat an estimated 16,000 square feet of surface. |
| EPA Registration No. | 1021-2574 |
| Shelf Life | Onslaught can last up to 3 years in storage when stored in a cool, dry area under lock and key. Store away from food, pet food, feed, seed, fertilizers, and veterinary supplies. Place liquid formulations on lower shelves and dry formulations above. |
| Comparable Products | Cyzmic CS, Fenvastar EcoCap |
| Children or pets? | No |
| Property Characteristics | None |
*Price does not include freight. We guarantee our rate plus shipping will be less than anyone else's price.