Agriculture: Lettuce Pest Management Guidelines

Relative Toxicities of Insecticides and Miticides Used in Lettuce to Natural Enemies and Honey Bees

Common name
(Example trade names)
Mode of action1 Selectivity2 (affected groups) Predatory mites3 General predators4 Parasites4 Honey bees5 Duration of impact to natural enemies6
abamectin (Agri-Mek SC) 6 moderate (mites, leafminers) M L M/H I long to predatory mites and affected insects
acephate (Orthene) 1B broad (insects, mites) H H M/H I intermediate
acetamiprid (Assail) 4A moderate (sucking insects, larvae) 7 8 II moderate
azadirachtin (AzaGuard, Neemix) 18B broad (insects, mites) M L/M L/M II short
Bacillus thuringiensis ssp. aizawai 11A narrow (caterpillars) L L L II short
Bacillus thuringiensis ssp. kurstaki 11A narrow (caterpillars) L L L III short
Beauveria bassiana (Mycotrol) broad (insects) L L/M L II
bifenthrin (Capture) 3A broad (insects, mites) H H H I long
chlorantraniliprole (Coragen) 28 narrow (primarily caterpillars) L L L/M III short
clothianidin (Belay) 4A — (lygus, aphids) M/H M/H I long
cyantraniliprole (Exirel) 28 narrow (thrips, leafminers) short
cyfluthrin (Baythroid XL) 3A broad (insects, mites) H H H I moderate
cyromazine (Trigard) 17 narrow (leafminers) L L L II short
diazinon (WP, EC) 1B broad (insects, mites) L H H I moderate to long
dimethoate (E) 1B broad (insects, mites) H H H I long
dinotefuran (Venom) 4A narrow (sucking insects) L L I short
emamectin benzoate (Proclaim) 6 narrow (caterpillars) I
esfenvalerate (Asana) 3A broad (insect, mites) H M H I moderate
flonicamid (Beleaf) 9C narrow (aphids) L L L III short
flupyradifurone (Sivanto) 4D narrow (aphids, leafhoppers) II
imidacloprid (Admire Pro) 4A narrow (sucking insects, beet armyworms, cutworms) L L I
indoxacarb (Avaunt) 22 narrow (caterpillars) L L L I moderate
insecticidal soap (M-Pede) broad (exposed insects, mites) M M M III short
lambda-cyhalothrin (Warrior II) 3A broad (plant bugs, beetles, caterpillars) H H H I moderate
malathion 1B broad (insects, mites) M H H I moderate
methomyl (Lannate SP, LV) 1A broad (insects, mites) H H H I moderate
methoxyfenozide (Intrepid 2F) 18A narrow (caterpillars) L L L II short
permethrin (Ambush, Pounce) 3A broad (insects, mites) L H H I long
permethrin (Permethrin Cutworm Bait) 3A broad (insects, mites)
polyhedral occlusion bodies (OBs) of the nuclear polyhedrosis virus of Helicoverpa zea (Gemstar) narrow (caterpillars)
polyhedral occlusion bodies (OBs) of the nuclear polyhedrosis virus of Spodoptera exigua (Spod-X) narrow (caterpillars)
pymetrozine (Fulfill) 9B narrow (aphids, whiteflies) L L L II short
spinetoram (Radiant) 5 narrow (caterpillars, thrips, whiteflies, aphids, leafminers) L/H M9 L/M II moderate10
spinosad (Success, Entrust) 5 narrow (caterpillars, whiteflies, aphids, leafminers) L M9 L/M II moderate9
spiromesifen (Oberon SC) 23 narrow (whiteflies) II
spirotetramat (Movento) 23 narrow (aphids, whiteflies) L L L II short
thiamethoxam (Actara, Platinum) 4A narrow (sucking insects) M I moderate
zeta-cypermethrin (Mustang) 3A broad (insects, mites) H M M I moderate
H = high    M = moderate    L = low     — = no information
1 Rotate chemicals with a different mode-of-action group number, and do not use products with the same mode-of-action group number more than twice per season to help prevent development of resistance. For example, the organophosphates have a group number of 1B; chemicals with a 1B group number should be alternated with chemicals that have a group number other than 1B. Mode-of-action group numbers are assigned by IRAC (Insecticide Resistance Action Committee).
2 Selectivity: Broad means it affects most groups of insects and mites; narrow means it affects only a few specific groups.
3 Generally, toxicities are to western predatory mite, Galendromus occidentalis.
4 Toxicities are averages of reported effects and should be used only as a general guide. Actual toxicity of a specific chemical depends on the species of predator or parasite, environmental conditions, and application rate.
5 Ratings are as follows: I–Do not apply or allow to drift to plants that are flowering; II–Do not apply or allow to drift to plants that are flowering, except when the application is made between sunset and midnight if allowed by the pesticide label and regulations; III–No bee precaution, except when required by the pesticide label or regulations. For more information, see Bee Precaution Pesticide Ratings.
6 Duration: Short means hours to days; moderate means days to 2 weeks; and long means many weeks or months.
7 May cause flare-ups of spider mite numbers.
8 Acute toxicity low but reproductive capacity is impacted.
9 Toxic against some natural enemies (predatory thrips, syrphid fly larva, beetles) when sprayed and 5 to 7 days after, especially for syrphid fly larvae.
10 Residual is moderate if solution is between pH of 7 to 8.

Acknowledgments: This table was compiled based on research data and experience of University of California scientists who work on a variety of crops and contribute to the Pest Management Guideline database, and from Flint, M. L. and S. H. Dreistadt. 1998. Natural Enemies Handbook: An Illustrated Guide to Biological Pest Control, ANR Publication 3386.

Text Updated: 04/17