Best Spray For Caterpillars On Trees: 10 Options Compared

#1 · Best Overall

1. Bonide Captain Jack's BT

• Form: Spray
• Weight: 2.3 lb
• Warranty Description: Warranty

Best for: Ready-to-use tree and garden spray.

Why it ranks #1: Ready-to-use BT lists tent caterpillars and use on shade trees and ornamentals; directions specify covering both tops and undersides of leaves.

Ready-to-use Bacillus thuringiensis spray lets you treat caterpillars on shade trees and ornamentals without first preparing a concentrate. Bonide Captain Jack’s lists tent caterpillars, cabbage loopers, and hornworms among its targets, making this 32-ounce option relevant for gardeners protecting trees alongside fruits and vegetables.

The ready-to-use bottle can be applied directly to the tops and undersides of leaves, so you can focus coverage on foliage where caterpillars feed. For broader application, the product can also be mixed with water and used with a hose-end sprayer, pressurized sprayer, or mist blower. Its listed use on shade trees, ornamentals, fruits, and vegetables gives it a range beyond tree care, while the stated effect on birds, earthworms, and beneficial insects is limited to no harm as described.

Skip it if you want a concentrate as your only application option; this bottle is supplied ready to use, though it can also be mixed with water.

Choose this Bonide spray if you want a ready-to-use caterpillar treatment for tree foliage and garden plants, with sprayer options for mixed application. It suits buyers who can cover both sides of leaves.

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

#2 · Best Hose-End

2. Summit Caterpillar and Webworm Control

• Form: Spray
• Warranty Description: Warranty

Best for: Hose-end treatment for trees.

Why it ranks #2: Its hose-end quart is described for shade and fruit trees and yields 12 to 24 gallons of spray when mixed with water.

A hose-end quart is the defining convenience of Summit Caterpillar and Webworm Control, connecting tree treatment to ordinary watering equipment rather than a separate pressurized sprayer. The biological control is mixed with water and yields 12 to 24 gallons of spray, giving shade- and fruit-tree owners a practical way to cover foliage.

The hose-end format supports a straightforward workflow for treating shade and fruit trees: attach the unit, mix with water, and spray the target foliage. Summit describes the control as biological and says a quart yields 12 to 24 gallons of material, which helps buyers gauge its potential coverage for tree work. The listed focus is caterpillars and webworms, so this is a more targeted choice than a general multi-insect garden spray.

Skip it if you need a ready-to-use bottle for treating individual plants; Bonide Captain Jack’s BT Ready-to-Use Spray is supplied for direct application.

This Summit option fits owners treating shade or fruit trees who value hose-end application and the stated 12-to-24-gallon yield. Pick it for caterpillars and webworms, not as a general-purpose pest spray.

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

#3 · Best Tree-Pest Range

3. Monterey B.t. Caterpillar Killer

• Form: Oil

Best for: Caterpillar spray for varied foliage.

Why it ranks #3: Lists shade trees and ornamentals along with bagworm, gypsy moth, fall cankerworm, and elm spanworm among its target caterpillars.

Coverage spanning shade trees, ornamentals, and named vegetable crops makes Monterey B.t. a flexible foliage treatment for caterpillars and worm-type insects. This 32-ounce spray lists pests such as bagworms, gypsy moths, and cabbage loopers, connecting tree protection with edible-garden use.

Monterey lists shade trees and ornamentals alongside broccoli, celery, cabbage, turnip greens, cauliflower, melons, lettuce, and tomatoes, so the same product can address caterpillar problems across varied plantings. Its target list includes bagworms, gypsy moths, fall cankerworms, and elm spanworms. The supplied safety information directs users to wash thoroughly after mixing and applying, and to wash contaminated clothing separately before reuse, making cleanup part of the application routine.

Skip it if you want a ready-to-use bottle requiring no mixing; Bonide Captain Jack’s BT Ready-to-Use Spray is supplied for direct application.

Monterey B.t. fits gardeners treating caterpillars across shade trees, ornamentals, and listed vegetables. It makes sense when that broad foliage range matters and you can follow the stated washing precautions after mixing and application.

Listed on Amazon as: Monterey B.t. Organic Caterpillar Killer Spray, 32 oz with Spoon

#4 · Concentrate Option

4. Monterey BT Concentrate

• Form: Oil
• Weight: 16 oz

Best for: Concentrate for tree and crop foliage.

Why it ranks #4: This 16-ounce BT concentrate lists shade trees and ornamentals and names several tree-feeding caterpillars, including bagworm and gypsy moth.

A 16-ounce Monterey BT concentrate with a bundled measuring spoon gives caterpillar-focused gardeners a format for preparing spray as needed. Its listed uses span shade trees, ornamentals, and vegetables, while the named targets include bagworms, cabbage loopers, and gypsy moths.

The concentrate format and included measuring spoon support preparing measured batches instead of relying on a ready-to-use bottle. Monterey lists shade trees and ornamentals as well as crops including cabbage, cauliflower, lettuce, and tomatoes, offering flexibility across ornamental and edible plantings. Its pest list includes fall cankerworms and elm spanworms in addition to bagworms and cabbage loopers. The safety directions call for washing after mixing and applying, a relevant step in the spray workflow.

Skip it if you want direct application without preparing a batch; Bonide Captain Jack’s BT Ready-to-Use Spray is supplied ready to use.

Choose this Monterey concentrate if you treat trees and garden crops and prefer measured batch preparation with the bundled spoon. It suits buyers comfortable mixing spray and following the stated cleanup directions.

Listed on Amazon as: Monterey BT – Bacillus Thuringiensis for Organic Worm and Caterpillar Control Bundled with Measuring Spoon – Concentrate for BT Spray – 16 oz

#5

5. Southern Ag Thuricide HPC

• Form: Liquid
• Weight: 0.27 g

Best for: Compact concentrate for tree use.

Why it ranks #5: The 8-ounce concentrate is listed for trees, shrubs, and ornamentals, and its description says it controls listed caterpillars and worms.

Southern Ag Thuricide HPC is an 8-ounce concentrate explicitly listed for trees, shrubs, citrus, nuts, and ornamentals. Its supplied directions give a mixing rate of 2 to 4 teaspoons per gallon, helping buyers prepare a batch for caterpillars and worms across varied plantings.

The stated rate of 2 to 4 teaspoons per gallon gives a concrete starting point for preparing the liquid concentrate, while the listed use spans vegetables, citrus, nuts, shrubs, trees, ornamentals, and flowering plants. Its described active ingredient is Bacillus thuringiensis, and the product is identified as an organic insecticide with low toxicity to humans and animals. The concentrate format can serve mixed gardens, but application requires measuring and dilution.

Skip it if you prefer a ready-to-spray hose-end product for tree coverage; Summit Caterpillar and Webworm Control uses a hose-end format.

This Southern Ag concentrate fits gardeners treating trees alongside crops and ornamentals who want a stated dilution rate. It is a practical match for batch preparation, not for direct spraying from the bottle.

Listed on Amazon as: Southern Ag 100520028 13021 Caterpillar Control, 8 oz

#6 · Longest Listed Control

6. BioAdvanced Tree & Shrub Insect Killer

• Form: Liquid
• Weight: 2.1 lb

Best for: Longer-lasting tree pest coverage.

Why it ranks #6: Ready-to-spray for trees and shrubs, it lists caterpillars and says control of listed insects continues for up to two weeks.

Up to two weeks of control after one application is the key distinction of BioAdvanced Tree & Shrub Insect Killer. Its ready-to-spray bottle connects to a garden hose, helping tree and shrub owners apply a listed caterpillar treatment without mixing a concentrate first.

The hose-connected ready-to-spray bottle simplifies setup for outdoor trees and shrubs, while the stated fast-acting contact formula addresses caterpillars alongside aphids, adult Japanese beetles, and whiteflies. BioAdvanced says one application can continue killing and controlling listed insects for up to two weeks. That combination may suit buyers who want a broader pest list and a stated duration of protection, while keeping the use focused on trees and shrubs.

Skip it if you need a caterpillar treatment specifically listed for vegetables; Monterey B.t. Organic Caterpillar Killer Spray lists several vegetable crops.

Choose BioAdvanced if you want hose-connected application on trees and shrubs plus a listed two-week control period. It fits buyers addressing several named pests, but its supplied plant-use focus is trees and shrubs.

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
• Warranty Description: Warranty

Best for: Organic gardening concentrate.

Why it ranks #7: Its BT kurstaki concentrate targets caterpillars, gypsy moth larvae, worms, and cabbage loopers, though the supplied data does not specify tree use.

OMRI listing and use up until the day of harvest distinguish Safer Brand Caterpillar Killer II for organic gardeners treating caterpillars. This 16-fluid-ounce concentrate contains Bacillus thuringiensis var. Kurstaki and lists tomato hornworms, gypsy moth larvae, worms, and cabbage loopers among its targets.

As a concentrate, this product is a fit for buyers willing to prepare a spray rather than use a ready-to-spray bottle. Its listed targets include tomato hornworms, gypsy moth larvae, worms, and cabbage loopers, giving the treatment a defined caterpillar focus. Safer says it can be used up until the day of harvest and, when used as directed, has no effect on birds, earthworms, or beneficial insects such as honeybees and ladybugs.

Skip it if you want a ready-to-spray hose connection; BioAdvanced Tree & Shrub Insect Killer comes in a hose-connected ready-to-spray bottle.

Safer Brand suits organic gardeners who need a caterpillar-focused concentrate for garden or field use and value the stated harvest timing. It is less suited to buyers seeking a ready-to-spray application.

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

#8

8. Southern Ag Thuricide BT

• Form: Liquid
• Weight: 9.9 oz

Best for: Liquid biological caterpillar control.

Why it ranks #8: This liquid biological insecticide uses Bacillus thuringiensis, but the supplied product details do not list target tree types or application format.

A liquid Bacillus thuringiensis biological insecticide gives Southern Ag Thuricide BT a focused role in caterpillar control. This 16-ounce pint is identified as using the same active ingredient as Dipel, making it a straightforward option for buyers seeking a liquid Bt product rather than a multi-purpose garden spray.

The supplied information describes this Southern Ag product as a biological insecticide made from a bacterium toxic to certain pests, with Bacillus thuringiensis in liquid form identified as its active ingredient. That focused description suits buyers specifically seeking BT caterpillar control, rather than a spray whose stated purpose spans fungi or mites. The product details do not provide a named list of target insects or specific tree-use directions, so buyers have less supplied guidance on those points.

Skip it if you need named target pests and listed tree-use directions; Monterey B.t. Organic Caterpillar Killer Spray specifies both.

This Southern Ag pint suits buyers seeking a liquid Bt biological insecticide for caterpillar control. Choose it when that focused product type is the priority, while recognizing that the supplied information gives few application specifics.

Listed on Amazon as: Southern Ag Thuricide BT Caterpillar Control, 16oz – Pint

#9

9. Safer Garden Insect Control

• Form: Spray
• Weight: 1.7 lb
• Warranty Description: Warranty

Best for: Natural-oil multi-insect plant spray.

Why it ranks #9: The natural-oil spray lists caterpillars and use on trees, but it is a broad multi-insect formula rather than a focused BT product.

Natural oils and a broad named pest list distinguish Safer Brand Garden Insect Control from caterpillar-only treatments. This 24-fluid-ounce spray lists caterpillars along with aphids, beetles, earwigs, spider mites, and stink bugs, with stated use on trees, shrubs, fruits, and vegetables.

The spray’s broad pest list can suit gardeners addressing more than caterpillars, while its listed plant range includes trees, shrubs, ornamentals, houseplants, fruits, and vegetables. Safer describes the formula as made with natural oils and gentle on plants, and says it is safe around children and pets when used as directed. The product can be used up to the day of harvest, which may be useful for edible plantings as well as ornamental trees.

Skip it if you need a Bt-focused caterpillar product for tree foliage; Monterey B.t. Organic Caterpillar Killer Spray lists shade trees and caterpillars.

Safer Brand fits gardeners who want one natural-oil spray for caterpillars and other listed pests across trees and edible plants. It suits broader pest care, rather than a focused Bt caterpillar-control approach.

Listed on Amazon as: Safer Brand Garden SG5110 Insect Control and Killer Spray – Kills Aphids Beetles, Boxelder Bugs, Caterpillars, Earwigs, Spider Mites, Stink Bugs & More – Natural Oils Gentle on Plants – 24 fl oz

#10

10. Bonide Captain Jack's Neem Oil

• Form: Liquid
• Weight: 2.3 lb
• Warranty Description: Warranty

Best for: Multi-purpose neem oil plant spray.

Why it ranks #10: Neem oil is listed for trees and claims control of all insect stages, but the supplied details do not specifically name caterpillar pests.

Three roles in one bottle—fungicide, insecticide, and miticide—make Bonide Captain Jack’s Neem Oil Spray broader than a caterpillar-only treatment. The ready-to-use 32-ounce spray is listed for trees, shrubs, fruits, nuts, and vegetables, and its neem oil targets multiple insect life stages.

The ready-to-use format lets you apply the spray directly to plants without mixing a concentrate, and the directions call for covering all surfaces, including leaf undersides. Its neem oil is described as controlling listed pests at egg, larval, and adult stages, while also addressing mites and fungal diseases such as powdery mildew. That breadth can suit gardeners managing several plant problems, though the product is not presented as a caterpillar-specific Bt treatment.

Skip it if you want a Bt caterpillar-specific product for tree foliage; Bonide Captain Jack’s BT Ready-to-Use Spray lists tent caterpillars.

Pick this Bonide neem oil spray if you want one ready-to-use product covering insects, mites, and fungal diseases on trees and other garden plants. Its broad role may not fit a Bt-specific caterpillar plan.

Listed on Amazon as: Bonide Captain Jack's Neem Oil Spray for Plants, 32 oz Ready-to-Use