Spinosad

📋 Key Facts at a Glance

Chemical Class

Naturalyte (biological origin)

Signal Word

Caution

OMRI Listed

Yes — approved for certified organic production

Mode of Action

Dual — nicotinic acetylcholine + GABA (unique — no cross-resistance)

Bee Toxicity

Moderate when wet; low once dried — apply in evening when bees aren't foraging

Aquatic Toxicity

Low

Residual Duration

7-14 days outdoor; longer indoors

🎯 Primary Uses in Pest Control

Spinosad is used for: fire ant bait (Fertilome Come and Get It, Monterey Garden Insect Spray), caterpillar/worm control in gardens, veterinary flea treatments (Comfortis, Capstar for dogs; Natroba for human lice), thrips control, and leafminer treatment. It's particularly valued where resistance to conventional insecticides is a problem.

🛡️ Safety Summary

Among the safest insecticides for mammals, birds, and most non-target invertebrates. Well-tolerated by dogs and cats at veterinary use rates. Approved for use around food crops close to harvest. Primary non-target concern: moderately toxic to bees when wet — apply in evening after bees have returned to hives.

🔬 Resistance Status

Limited resistance documented — the dual mode of action slows resistance development. Some resistance in diamondback moth (agricultural) after extended use. In structural pest control, resistance is not a significant concern.

🏷️ Common Products Containing Spinosad

Comfortis (fleas)Capstar (fleas)Conserve SCMonterey Garden Insect SprayFertilome Come and Get ItSpinosad Fire Ant Bait

❓ FAQ

Is spinosad safe for cats?

Spinosad is FDA-approved for veterinary use in cats at established dosage rates (Natroba shampoo for head lice treatment is safe for cats). Environmental applications at labeled rates are considered low risk for cats compared to pyrethroids.

Does spinosad kill beneficial insects?

Spinosad is toxic to most insects — it doesn't discriminate between pests and beneficials. It's toxic to bees when wet but relatively safe once dry. Apply in evening to avoid bee exposure. It breaks down in UV light, reducing residual activity compared to synthetic insecticides.

Spinosad Biopesticide Profile