Agriculture: Asparagus Pest Management Guidelines

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

Common name (trade name) Mode of action1 Selectivity2(affected groups) Predatory mites3 General predators4 Parasites4 Honey bees5 Duration of impact to natural enemies6
acetamiprid (Assail) 4A broad (many insects) II moderate
Bacillus thuringiensis ssp. aizawai 11A narrow (caterpillars) L L L II short
carbaryl (Sevin) bait 1A narrow (cutworms, armyworms) L L L III short
carbaryl (Sevin XLR Plus) 1A broad (insects) L H H I long
chlorantraniliprole (Coragen) 28 narrow (primarily caterpillars) L L L/M III short
chlorpyrifos (Lorsban) 1B broad (insects, mites) M H H I moderate
methomyl (Lannate) 1A broad (insects) H H H I moderate
permethrin (Ambush, Pounce) 3A broad (insects) L H H I long
narrow-range oil (JMS Stylet Oil) un broad (exposed insects) L7 L L II short
pymetrozine (Fulfill) 9B narrow (aphids) L L L II short
pyrethrin (PyGanic) 3A broad (insects) M M I short
spinetoram (Radiant) 5 narrow (caterpillars, thrips, aphids) L/H M8 L/M II moderate9
spinosad (Entrust, Success) 5 narrow (caterpillars, thrips, aphids) L/H M8 L/M II short to moderate8
H = high          M = moderate            L = low           — = no information             un = unknown or uncertain mode of action
1 Rotate insecticides 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 the development of resistance. For example, the organophosphates have a group number of 1B; insecticides with a 1B group number should be alternated with insecticides 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. Where differences have been measured in toxicity of the pesticide-resistant strain versus the native strain, these are listed as pesticide-resistant strain/native strain.
4 Toxicities are averages of reported effects and should be used only as a general guide. Actual toxicity of a specific insecticide 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 about pesticide synergistic effects, 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 Rating depends on rate used.
8 Toxic against some natural enemies (predatory thrips, syrphid fly and lacewing larvae, beetles) when sprayed and up to 5 to 7 days after, especially for syrphid fly larvae.
9 Residual is moderate if solution is between pH of 7 to 8.

Acknowledgements: 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 Guidelines 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: 08/19