Spinosad: What It Kills, Bee Safety and How to Use It in the Garden

Updated November 12, 2026

Spinosad is one of the two common microbial insecticides home gardeners reach for, along with Bt (UF/IFAS Gardening Solutions). It is a go-to for caterpillars, leafminers and thrips, but it misses whole groups of pests, it is hard on bees until it dries, and not every spinosad bottle is organic. Here is what it kills, how to spray it without hurting pollinators, how it compares with Bt, neem and spinetoram, and how to keep it working. For a side-by-side of all the low-risk sprays, see soap vs. neem vs. horticultural oil; for pest-by-pest plans, see organic pest control for vegetable gardens.

Use any product as the label directsUMN Extension: “Always follow the pesticide label directions ... Be sure that the plant you wish to treat is listed on the label ... And observe the number of days between pesticide application and when you can harvest your crop. Remember, the label is the law.”

What is spinosad?

• Made by a soil bacterium. NPIC: “Spinosad is a natural substance made by a soil bacterium that can be toxic to insects. It is a mixture of two chemicals called spinosyn A and spinosyn D.” It has been registered by the U.S. EPA for use in pesticides since 1997 (NPIC).
• No live bacteria. The bacterium, Saccharopolyspora spinosa, is grown in large vats and the active ingredients are harvested and formulated. Mississippi State: “The final product does not contain any live bacteria, only the toxins produced by the bacteria.” (Mississippi State Extension)
• How it kills. It “affects the nervous system of insects that eat or touch it”, causing paralysis and death, “typically within 1-2 days” (NPIC). UF/IFAS: “Feeding stops within minutes and death occurs within two days.” (UF/IFAS EDIS IN197)
• Eaten works better than touched. Cornell Cooperative Extension: it “has contact activity, but is even more active when ingested.” (Cornell Cooperative Extension)
• It moves a short way into leaves. UC IPM: spinosad “persists about 1 week and it has translaminar activity (is absorbed short distances into plant tissue).” (UC IPM)

What does spinosad kill (and what does it miss)?

Every source agrees on the core list: caterpillars, leafminers and thrips. Beyond that the lists differ, so match the pest to the product label before you spray.

About this table: Lists quoted or summarized from each source as published. Where they disagree, both are shown rather than merged.

Where sources disagreeSpider mites: UF/IFAS and NPIC list them; UC Master Gardeners (San Luis Obispo County) say spinosad does not work on mites. Stink bugs: Mississippi State says it is not effective on them, while UGA’s organic options table lists spinosad among choices for stink bugs (UGA Extension). Cucumber beetles: Mississippi State’s home-garden newsletter says spinosad does not control them, while Mississippi State’s guide for commercial organic farms lists it among foliar sprays for them (Mississippi State Extension). For cucumber beetles, start with the row cover and timing in our cucumber beetle section.

Fall and winter brassicas. Mississippi State notes that cabbage, bok choy, broccoli and collards grown in fall are attacked by armyworms, loopers, cabbageworms and diamondback moths, which “tend to be more abundant in the fall”, and calls spinosad “one of the most effective treatments available” (Mississippi State Extension; Mississippi conditions). Row cover from planting to harvest comes first: see organic cabbage worm control.

Is spinosad safe for bees?

Not while it is wet. Every source below agrees on that; they differ on how fast the risk drops.

• NPIC: “Spinosad is very highly toxic to bees. However, evidence suggests that spinosad has little or no effect on honey bees and other beneficial insects after sprays have dried.” (NPIC)
• UF/IFAS: it is “highly toxic to bees when the spray is wet, but dry residues have minimal effect”, so spray “during the early morning or late evening, or at night when pollinators are not actively foraging.” (UF/IFAS EDIS IN197)
• UC IPM: spinosad “can be toxic to certain natural enemies (e.g., predatory mites, Trichogramma wasps, and syrphid fly larvae) and bees when sprayed and for about 1-4 days afterwards; do not apply spinosad to plants that are flowering.” (UC IPM)
• UC IPM bee precaution rating: II. That means do not apply or let it drift onto flowering plants, including weeds, except between sunset and midnight where the label allows (UC IPM). See bee ratings for every organic spray.
• Butterflies too. Cornell Cooperative Extension says spinosad “should not be sprayed or allowed to drift in known habitats for threatened or endangered species of caterpillars and butterflies.” (Cornell Cooperative Extension)

How long after spraying is spinosad safe for bees? Sources disagree

About this table: Figures shown as each source states them. They measure different things (dried residues in field studies, product-to-product drying time, and a cautious window for natural enemies and bees), so do not average them.

Safest reading: don’t spray plants in bloom, spray when bees aren’t flying, let the spray dry, and follow the label.

Is spinosad safe for vegetables, people and pets?

• People and pets: NPIC: “Spinosad is low in toxicity to people and other mammals. However, if it gets on your skin or in your eyes it can cause irritation and redness.” The EPA classifies spinosad as not likely to cause cancer (NPIC).
• Drugs are separate products. Some FDA-regulated drugs contain spinosad and are used for head lice on people and fleas on dogs and cats (NPIC). A garden spray is not one of them: never use it on people or pets, and ask a doctor or veterinarian about those products.
• Edible crops: spinosad products are labeled for use on many vegetable crops (Mississippi State Extension). Check that your crop is on the label, and wait the pre-harvest interval (PHI), the time between spraying and harvest. UF/IFAS says the PHI for spinosad “is lower than most conventional pesticides, but still important.” (UF/IFAS Gardening Solutions)

Is spinosad organic?

• Some products are. NPIC: “Some of these products are approved for use in organic agriculture.” UC IPM says “the Entrust formulation of spinosad” is “acceptable for use on an organically grown crop” (UC IPM).
• Not every bottle. Mississippi State says some home products are approved for organic gardeners, but “some products contain inorganic inert ingredients that prevent them from being considered as fully organic.” (Mississippi State Extension) UGA: “spinosad products come in both “organic” products and conventional products.” (UGA Extension)
• What to look for. Cornell: “Some spinosad products are OMRI-listed and on the EPA Reduced Risk list.” (Cornell Cooperative Extension) Check the label for an OMRI listing or an organic-use statement, or ask your certifier if you sell certified organic produce.

How to use spinosad in the garden

1. Identify the pest first. UF/IFAS: “using Bt and Spinosad responsibly means identifying pests before you treat.” (UF/IFAS Gardening Solutions) Check that it is a pest spinosad controls (see the tables above) and that your plant is on the label.
2. Treat small, early. For caterpillars, UMN says “The best time to treat caterpillars is while they are still small” (UMN Extension).
3. Spot-treat. UF/IFAS: “Apply them to problem areas, not the whole garden.” (UF/IFAS Gardening Solutions)
4. Time it for bees. Spray in the early morning, late evening or at night when pollinators are not foraging (UF/IFAS IN197), never on flowering plants (UC IPM), and let it dry.
5. Follow the label for the rate, how often you may reapply, the number of applications per season and the crop’s pre-harvest interval (UF/IFAS).
6. Rotate. Alternate with other methods and with products outside insecticide Group 5 (see resistance below).

Spinosad vs Bt, neem oil and spinetoram

• Spinosad vs Bt. Bt (Bacillus thuringiensis subsp. kurstaki) works only on caterpillars, and UMN says “Caterpillars must eat it to be effective” (UMN Extension). Spinosad reaches more kinds of pests, and Mississippi State calls it “much more effective than the Bt products gardeners traditionally used for caterpillars” (Mississippi State Extension). The trade-off is bees: UC IPM rates Bt kurstaki III (no bee precaution beyond the label) and spinosad II (UC IPM).
• Spinosad vs neem oil. They do different jobs. Cornell Cooperative Extension describes azadirachtin, the active ingredient in neem, as an insect growth regulator and anti-feedant that “is effective at controlling insect immature stages” (Cornell Cooperative Extension); spinosad kills caterpillars, leafminers and thrips outright. UC IPM rates both II for bees (UC IPM). The full comparison is on soap vs. neem vs. horticultural oil.
• Spinosad vs spinetoram. Michigan State University Extension lists spinetoram (example: Radiant SC) and spinosad (example: Entrust SC) as IRAC Group 5 insecticides: “Switching between them does not constitute rotation to a different mode of action. Entrust is approved for use in organic production when used in accordance with organic certification requirements, but its mode of action is closely related to that of Radiant.” (Michigan State University Extension) UC IPM also rates spinetoram II for bees, the same as spinosad (UC IPM). So spinetoram is not a way to rotate away from spinosad.

Don’t overuse it: resistance

• UGA Extension: “Because spinosad is very effective against some pests, people tend to use it every time. Using the same product repeatedly increases the risk that the pest will develop resistance.” Rotate or combine it with other controls (UGA Extension).
• Colorado potato beetle: UMN: “Entrust (spinosad) resistance is present on some farms.” (UMN Extension) More on this on our Colorado potato beetle section.
• Spotted wing drosophila (commercial berries): Cornell advises rotating to a different active ingredient after “no more than two or three (depending on the crop label) Entrust (group 5 insecticide) sprays” (Cornell University). That advice is for commercial fruit growers, but the principle carries over to home plantings.

What happens to spinosad in soil and water

• Sunlight breaks it down. “Spinosad is broken down rapidly by sunlight.” In sunlight its half-lives on leaves are 2 to 16 days (NPIC).
• Soil. Soil half-lives of 9 to 17 days have been reported. It sticks to soil and has “a very low potential to move through soil towards ground water” (NPIC).
• Water life. NPIC: it is “practically non-toxic to moderately toxic to fish depending on the species”, “very highly toxic to eastern oysters” and “moderately toxic to earthworms.” Keep spray and rinse water out of ponds, streams and storm drains (NPIC).

Spinosad alternatives by pest

• Small caterpillars only: Bt kurstaki, sprayed so caterpillars eat it (UMN). UF/IFAS warns that butterfly caterpillars are as vulnerable to Bt as pest caterpillars, so avoid plants that host butterflies, such as milkweed (UF/IFAS Gardening Solutions).
• Soft-bodied insects you can wet directly (aphids, whiteflies, mites): insecticidal soap or horticultural oil; see soap vs. neem vs. oil.
• Barriers and handpicking: floating row cover and picking pests into soapy water; see organic pest control for vegetable gardens.

More organic guides

Organic pest control Soap vs. neem vs. oil Bee ratings before you spray Organic broccoli Organic cabbage Organic gardening hub