Best Bag Worm Spray For Trees: Compare 10 Spray Options

#1 · Best Overall

1. Fertilome Spinosad RTS

• Form: Spray
• Weight: 2.3 lb

Best for: Ready-to-spray multi-site control.

Why it ranks #1: Explicitly lists bagworms and describes use on ornamental trees; its ready-to-spray quart provides a convenient application format without mixing guesswork.

The ready-to-spray format and user-friendly, no-guesswork positioning make this Fertilome option convenient for buyers treating bagworms across several outdoor areas. Its listed sites include ornamental trees, shrubs, flowers, lawns, citrus, fruits, and vegetables, with named targets extending to tent caterpillars and other chewing insects.

Because this is identified as an RTS spray, it offers a simpler application workflow than a concentrate that must be diluted separately. Fertilome lists bagworms, tent caterpillars, armyworms, sod webworms, loopers, and other insects among its targets, and names ornamental trees and shrubs alongside lawns and edible plantings. That combination fits a yard with varied treatment sites. The product is a quart spray, but the listing does not state a hose-end connection, so do not assume that specific application method.

Skip it if you specifically need a hose-end tree sprayer; Summit 021-6 Caterpillar and Webworm Control is identified as hose-end ready to spray.

This RTS quart suits buyers treating bagworms and other listed insects across ornamental trees, shrubs, and additional yard or garden sites. Choose it for ready-to-spray convenience, not an explicitly listed hose-end setup.

Listed on Amazon as: Fertilome Spinsosad Bagworm, Tent Caterpillar and Chewing Insect Control, RTS, Quart

#2 · Best Bagworm Concentrate

2. Fertilome Spinosad Concentrate

• Form: Oil
• Weight: 16 oz

Best for: Organic-use spinosad concentrate.

Why it ranks #2: Names bagworms among its controlled insects and is designed for outdoor use on trees and shrubs; concentrate format suits buyers who mix spray.

OMRI-listed spinosad concentrate gives this Fertilome bottle a clear fit for buyers seeking an organic-use option for bagworms and other listed chewing insects. Its outdoor use spans trees, shrubs, flowers, fruits, citrus, and vegetables, making it relevant when one treatment product must serve several garden areas.

The 16-ounce bottle is a concentrate, and Fertilome identifies it as water-soluble, so buyers should plan for mixing rather than treating it as a ready-to-spray product. Its listed target range includes bagworms, tent caterpillars, leafminers, borers, leaf rollers, and thrips, while the stated outdoor application sites include trees and shrubs as well as fruits and vegetables. That breadth can suit mixed plantings, though the listing does not specify a ready-to-use hose-end workflow.

Skip it if you want a ready-to-spray spinosad treatment with no separate concentrate mixing; Fertilome Spinsosad RTS is listed as a user-friendly spray.

Choose this bottle if you want an OMRI-listed spinosad concentrate for bagworms across trees and other outdoor plantings. Its concentrate format means mixing is part of the application workflow.

Listed on Amazon as: Fertilome (16062) Spinosad Insecticide, Spinosad Bagworm, Tent Caterpiller & Chewing Insect Killer, OMRI Listed (16 oz.)

#3 · Best Bt for Trees

3. Monterey B.t. Killer

• Form: Oil

Best for: Measured Bt for shade trees.

Why it ranks #3: Lists bagworm among its target caterpillars and shade trees among suitable plants; the 8-ounce powder includes a measuring spoon.

A supplied spoon lets buyers measure Monterey B.t. Caterpillar & Worm Killer, an 8-ounce product listing bagworms among its targets. Its stated foliage uses include shade trees and ornamentals, so the small-format powder-and-measure setup may suit a gardener treating those plants for caterpillars and worm-type insects.

Monterey lists the product for caterpillars and worm-type insects, including bagworms, gypsy moth, and fall cankerworm, and names shade trees and ornamentals among its foliage sites. The included spoon provides a measuring tool for preparing an application, rather than a ready-to-spray hose-end workflow. Monterey also states it is safe for earthworms and bees when used as directed. Buyers should follow the supplied product directions and safety guidance when mixing and applying it.

Skip it if you want hose-end application without measuring; Summit 021-6 Caterpillar and Webworm Control is a hose-end quart for tree spraying.

Consider Monterey for measured application against listed caterpillars and worms on shade trees or ornamentals. It includes a spoon, but the listed format is not a ready-to-spray hose-end bottle.

Listed on Amazon as: Monterey B.t. Caterpillar & Worm Killer, 8 oz with Spoon

#4 · Best Hose-End Spray

4. Summit Caterpillar Control

• Form: Spray

Best for: Hose-end tree spraying.

Why it ranks #4: Its hose-end quart is designed for shade and fruit trees and yields 12 to 24 gallons; listed targets are caterpillars and webworms, not bagworms specifically.

The hose-end quart connects the application method directly to shade and fruit trees, so you can spray without first preparing a separate tank mix. Summit describes this as biological caterpillar and webworm control; mixed with water, the quart yields 12 to 24 gallons of material for outdoor use.

A hose-end component makes the product a practical fit for buyers who want to apply it through a garden hose, while the listed 12-to-24-gallon yield gives a stated coverage volume after mixing with water. Its target pests are caterpillars and webworms, and the description specifically calls out shade and fruit trees. The straightforward workflow suits tree spraying, but the application depends on access to a hose and water rather than a standalone ready-to-use trigger bottle.

Skip it if you need a ready-to-spray bottle without connecting a hose; BioAdvanced Tree & Shrub Insect Killer comes ready to connect to a garden hose.

Choose this Summit quart for caterpillar and webworm treatment on shade or fruit trees when hose-end application suits your setup. Its stated yield is 12 to 24 gallons, but it requires a hose and water.

Listed on Amazon as: SUMMIT 021-6 Caterpillar and Webworm Control-Hose End For Insects, 1-, Quart, White

#5

5. Natural Guard Spinosad Control

• Form: Oil
• Weight: 2 lb

Best for: Quart-size spinosad oil option.

Why it ranks #5: The title identifies Fertilome spinosad control for bagworms and tent caterpillars in a quart; the listing supplies few further application details.

The quart-size Fertilome Spinosad Bagworm, Tent Caterpillar and Chewing Insect Control Oil identifies its focus in the product name: spinosad treatment for bagworms, tent caterpillars, and other chewing insects. Its listed item form is oil, a relevant format detail for buyers comparing application products.

The product title names bagworms and tent caterpillars, making those targets directly relevant to a tree-pest roundup, and also describes control of chewing insects. Its quart size offers a larger listed quantity than the 8-ounce Monterey B.t. product, while the specified oil form distinguishes it from products explicitly identified as sprays or concentrates. The supplied facts do not establish a hose-end connection or ready-to-spray workflow, so buyers should not assume either application method from the title alone.

Skip it if you require an explicitly listed hose-end application; Summit 021-6 Caterpillar and Webworm Control identifies a hose-end format for trees.

This is a relevant option for buyers comparing quart-size oil products named for bagworms and tent caterpillars. The supplied facts do not specify a hose-end or ready-to-spray application workflow.

Listed on Amazon as: Fertilome Spinosad Bagworm, Tent Caterpillar and Chewing Insect Control Oil, Quart

#6

6. BioAdvanced Tree & Shrub Spray

• Form: Liquid
• Weight: 2.1 lb

Best for: Two-week tree and shrub protection.

Why it ranks #6: Ready-to-spray hose connection and tree-and-shrub use are convenient, and caterpillars are listed; bagworms are not named in the provided pest list.

Protection lasting up to two weeks after one application is the defining feature of BioAdvanced Tree & Shrub Insect Killer. Its ready-to-spray bottle connects to a garden hose, combining convenient outdoor application with contact control for listed pests including caterpillars, aphids, adult Japanese beetles, and whiteflies.

The hose-connected ready-to-spray bottle streamlines application on trees and shrubs without requiring a separate concentrate-mixing step. BioAdvanced states that one application quickly kills listed insects on contact and continues to kill and control them for up to two weeks. That interval is useful for buyers seeking ongoing coverage after spraying, while the listed pest range makes it relevant beyond bagworms alone. Its stated use centers on outdoor trees and shrubs, not a broad indoor treatment workflow.

Skip it if you want a concentrate for custom dilution and an OMRI-listed organic gardening option; Atticus Spliven is a spinosad concentrate approved for organic use.

This suits tree and shrub owners who want hose-connected spraying plus stated protection for up to two weeks. Consider whether that interval and its listed pest targets match your treatment needs before choosing it.

Listed on Amazon as: BioAdvanced Tree & Shrub Insect Killer Spray – Outdoor Pest Control – 32 oz

#7

7. Safer Caterpillar Killer II

• Form: Liquid
• Weight: 1 lb

Best for: Organic-use caterpillar concentrate.

Why it ranks #7: The concentrate kills caterpillars and worms and is OMRI Listed; its supplied description does not specifically name bagworms or tree use.

OMRI listing and use up until the day of harvest distinguish Safer Brand Caterpillar Killer II for gardeners treating leaf-feeding worms near harvest. The 16-fluid-ounce concentrate contains Bacillus thuringiensis var. kurstaki and targets caterpillars, gypsy moth larvae, worms, and cabbage loopers.

As a concentrate, this product calls for a mixing step, so it suits buyers comfortable preparing spray rather than seeking an immediate ready-to-use bottle. Its listed targets include caterpillars, gypsy moth larvae, worms, and cabbage loopers; the description explains that damaging caterpillars and worms stop feeding after ingesting it. OMRI listing and the stated ability to use it up until harvest are useful considerations for garden planning. Safer also states that, when used as directed, it has no effect on birds, earthworms, or beneficial insects.

Skip it if you want a ready-to-use Bt spray without mixing concentrate; Bonide Captain Jack’s Bt Thuricide is listed as ready to use.

This suits gardeners seeking an OMRI-listed caterpillar concentrate that can be used through harvest, subject to its directions. Account for the mixing step and confirm its listed targets fit your treatment need.

Listed on Amazon as: Safer Brand Caterpillar Killer II Concentrate Spray, 16 fl oz

#8

8. Bonide Captain Jack's Bt

• Form: Spray
• Weight: 2.3 lb

Best for: Ready-to-use caterpillar treatment.

Why it ranks #8: This ready-to-use Bt spray is listed for shade trees and tent caterpillars, but the supplied pest list does not specifically identify bagworms.

Captain Jack’s ready-to-use Bt spray targets worms and caterpillar-stage insects, including tent caterpillars, while its listed use includes shade trees and ornamentals. Bonide also states that it causes no harm to birds, earthworms, or beneficial insects such as honeybees and ladybugs when used as directed.

The 32-ounce ready-to-use spray avoids a concentrate-mixing step, and the directions support applying it directly to the tops and undersides of leaf surfaces. That leaf coverage guidance is relevant when treating foliage on shade trees and ornamentals. The listed target set includes cabbage loopers, hornworms, and tent caterpillars, while its stated impact on birds, earthworms, and beneficial insects is a useful selection consideration when used as directed. It is also listed for fruits and vegetables, extending use beyond trees.

Skip it if you need the listing to name fruit trees specifically; Summit 021-6 Caterpillar and Webworm Control explicitly describes shade and fruit trees.

Pick this Bonide spray for ready-to-use treatment of tent caterpillars on shade trees and ornamentals, with leaf-surface application guidance. Its supplied tree-use wording names shade trees and ornamentals rather than fruit trees.

Listed on Amazon as: Bonide Captain Jack's Bacillus Thuringiensis BT, 32 oz

#9

9. Atticus Spliven Concentrate

• Form: Liquid

Best for: Organic garden concentrate mixing.

Why it ranks #9: The 32-ounce spinosad concentrate is OMRI Listed and has easy-measure mix rates, but supplied details do not specify bagworms or tree use.

OMRI approval for organic gardening and a 0.5% spinosad active ingredient define Atticus Spliven for buyers planning garden insect control with a concentrate. Its easy-measure rates are provided for pint, quart, or gallon mixes, helping users prepare different batch sizes rather than rely on a ready-to-spray bottle.

Spliven is a liquid concentrate, and its listed measuring rates for pint, quart, or gallon mixes support preparing a quantity suited to the application at hand. The 0.5% spinosad content identifies its active ingredient, while OMRI listing supports its stated organic-gardening use. Those features make it relevant to buyers managing garden treatments across more than one batch size. The supplied information identifies garden insect control and organic use, but does not provide a specific tree-pest list in these facts.

Skip it if you want a ready-to-spray product specifically listing bagworms; Fertilome Spinsosad RTS names bagworms and comes in spray form.

This fits organic gardeners comfortable measuring concentrate for pint, quart, or gallon mixes. Its supplied facts support organic garden insect control, but do not identify a specific tree-pest list.

Listed on Amazon as: Atticus Spliven Organic Insecticide (32oz) Spinosad Concentrate for Gardens

#10

10. Summit and Spectracide Bundle

• Form: Spray

Best for: Two-product yard and tree set.

Why it ranks #10: The Summit component targets caterpillars and webworms on trees, but neither component is specifically described for bagworms; the bundle also adds unrelated lawn coverage.

This set pairs Summit’s hose-end caterpillar and webworm control with Spectracide’s QuickFlip-sprayer insect killer, covering distinct tree and yard workflows. Summit’s quart yields 12 to 24 gallons when mixed with water, while Spectracide is listed for 260-plus insects by contact across lawns, vegetables, fruits, flowers, trees, and shrubs.

The Summit component is specifically described for caterpillars and webworms on trees, with a hose-end sprayer and a stated 12-to-24-gallon yield after mixing. The Spectracide component adds contact control for more than 260 insects and a QuickFlip sprayer for lawns, extending the set beyond tree pests. This pairing may suit buyers managing multiple outdoor areas, but it combines two distinct products and application workflows rather than a single unified tree treatment.

Skip it if you only need a single-purpose caterpillar and webworm tree treatment; Summit 021-6 Caterpillar and Webworm Control is the tree-focused hose-end product.

Choose this set if you want Summit tree treatment alongside Spectracide coverage for lawns and other outdoor areas. Its two components have different targets and sprayers, so consider whether both workflows suit your yard.

Listed on Amazon as: SUMMIT Caterpillar & Webworm Control + Spectracide Triazicide Insect Killer (32 fl Oz)