Agriculture: Pear Pest Management Guidelines

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

Common name (Example trade name and formulation) Mode of action1 Selectivity2 (affected groups) Predatory mites3 General predators4 Parasites4 Honey bees5 Duration of impact to natural enemies6
abamectin (Agri-Mek EC) 6 moderate (mites, leafminers, psylla) H L M/H I long to predatory mites and affected insects
acequinocyl (Kanemite) 20B narrow (mites) III
acetamiprid (Assail) 4A moderate (caterpillars, sucking insects) 7 8 M/H II moderate
azadirachtin (Neemix) un broad (insects, mites) M L/M L/M II short
Bacillus thuringiensis ssp. kurstaki 11A narrow (caterpillars) L L L III none
bifenazate (Acramite) 20D narrow (mites) L L L II short
bifenthrin (Brigade) 3A broad (insects, mites) H H H I long
buprofezin (Centaur) 16 narrow (sucking insects) L H9 L II long
chlorantraniliprole (Altacor) 28 narrow (caterpillars) III
clofentezine (Apollo) 10A narrow (mites) L L L III short
clothianidin (Clutch) 4A M/H M/H I long
Cydia pomenella granulovirus (Cyd-X) un narrow (codling moth) none none none III none
diazinon (WP) 1B broad (insects, mites) L H H I moderate to long
diflubenzuron (Dimilin) 15 narrow (codling moth, katydids) L H L II short
dimethoate 1B broad (insects, mites) H H H I long
esfenvalerate (Asana) 3A broad (insect, mites) H M H I moderate
etoxazole (Zeal) 10B narrow (mites) 8 II short
fenpropathrin (Danitol) 3A broad (insects, mites) H H H I
fenpyroximate (Fujimite) 21A narrow (mites and some insects) H L L III short
formetanate hydrochloride (Carzol) 1A broad (insects, mites) M/H H H II long, unless washed off
hexythiazox (Savey, Onager) 10A narrow (mites) L L L II short to moderate
imidacloprid (Provado) 4A narrow (sucking insects) 7 H I short to moderate
kaolin clay (Surround) un broad (insects, mites) M M III long
lambda-cyhalothrin (Warrior) 3A broad (plant bugs, beetles, caterpillars) H H H I moderate
lime sulfur un narrow (mites, thrips) L/H L H II short
methoxyfenozide (Intrepid) 18 narrow (caterpillars) L L L II none
micronized sulfur un narrow (mites, thrips) L/H L/M H III short
neem oil (Trilogy) un broad (soft-bodied) insects) L L L II short
petroleum oil un broad (exposed insects, mites) L10 L L II short to none
phosmet (Imidan) 1B broad (insects, mites) H H H I moderate to long
pyridaben (Nexter) 21A broad (insects, mites) M/H M I short
pyriproxyfen (Esteem, Seize) 7C narrow (scale, beetles) L H9 L II long
spinetoram (Delegate) 5 broad (caterpillars, thrips, aphids, scales) L/M M M/H II moderate11
spinosad (Entrust, Success) 5 narrow (caterpillars, thrips, aphids, scales) L M L/M II short
spinosad (GF-120) 5 narrow (flies) L II short
spirodiclofen (Envidor) 23 narrow (mites) L II
spirotetramat (Movento) 23 narrow (aphids, scale) L L L II short
thiacloprid (Calypso) 4A moderate (sucking insects, larvae) 7 M/H M/H II moderate
thiamethoxam (Actara) 4A narrow (sucking insects) 7 M/H M/H I moderate
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 for insecticides and miticides (un=unknown or uncertain mode of action) 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 Toxicities are generally 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 factors including the application rate, environmental conditions, and life stage and species of parasite or predator.
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 May cause increases in spider mite numbers.
8 Acute toxicity low, but reproductive capacity impacted.
9 Kills lady beetles.
10 Rating depends on rate used.
11 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 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: 11/12