How to Manage Pests

UC Pest Management Guidelines


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

(Reviewed 11/12, updated 11/12)

In this Guideline:

Common name (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 I7 long to predatory mites and affected insects
acequinocyl (Kanemite) 20B narrow (mites) IV
acetamiprid (Assail) 4A moderate (caterpillars, sucking insects) 8 9 M/H IV moderate
azadirachtin (Neemix) 18B broad (insects, mites) M L/M L/M III short
Bacillus thuringiensis ssp. kurstaki 11.B2 narrow (caterpillars) L L L IV none
bifenazate (Acramite) 25 narrow (mites) L L L III short
bifenthrin (Brigade) 3 broad (insects, mites) H H H I-III10 long
buprofezin (Centaur) 16 narrow (sucking insects) L H11 L IV long
chlorantraniliprole (Altacor) 28 narrow (caterpillars)
chlorpyrifos (Lorsban EC) 1B broad (insects, mites) M H H I12 moderate
clofentezine (Apollo) 10A narrow (mites) L L L IV short
clothianidin (Clutch) 4A M/H M/H I long
Cydia pomenella granulovirus (Cyd-X) narrow (codling moth) none none none IV none
diazinon (WP) 1B broad (insects, mites) L H H I moderate to long
diflubenzuron (Dimilin) 15 narrow (codling moth, katydids) L H L IV short
dimethoate 1B broad (insects, mites) H H H I long
esfenvalerate (Asana) 3 broad (insect, mites) H M H I moderate
etoxazole (Zeal) 10B narrow (mites) 9 IV short
fenpropathrin (Danitol) 3 broad (insects, mites) H H H I
fenpyroximate (Fujimite) 21 narrow (mites and some insects) H L L IV short
flubendiamide (Belt) 28 L L L/M I short
formetanate hydrochloride (Carzol) 1A broad (insects, mites) M/H H H II13 long, unless washed off
hexythiazox (Savey, Onager) 10A narrow (mites) L L L IV short to moderate
imidacloprid (Provado) 4A narrow (sucking insects) 8 H II short to moderate
kaolin clay (Surround) broad (insects, mites) M M IV long
lambda-cyhalothrin (Warrior) 3 broad (plant bugs, beetles, caterpillars) H H H I14 moderate
lime sulfur narrow (mites, thrips) L/H L H IV short
methoxyfenozide (Intrepid) 18A narrow (caterpillars) L L L IV none
micronized sulfur narrow (mites, thrips) L/H L/M H IV short
neem oil (Trilogy) broad (soft-bodied) insects) L L L III short
petroleum oil broad (exposed insects, mites) L15 L L III 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 III short
pyriproxyfen (Esteem, Seize) 7C narrow (scale, beetles) L H11 L IV long
spinetoram (Delegate) 5 broad (caterpillars, thrips, aphids, scales) L/M M M/H III moderate16
spinosad (Entrust, Success) 5 narrow (caterpillars, thrips, aphids, scales) L M L/M III short
spinosad (GF-120) 5 narrow (flies) L III short
spirodiclofen (Envidor) 23 narrow (mites) L I
spirotetramat (Movento) 23 narrow (aphids, scale) L L L short
thiacloprid (Calypso) 4A moderate (sucking insects, larvae) 8 M/H M/H III moderate
thiamethoxam (Actara) 4A narrow (sucking insects) 8 M/H M/H II 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 the 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). For additional information, see their Web site at
2 Selectivity: Broad means it affects most groups of insects and mites; narrow means it affects only a few specific groups.
3 Generally, toxicites 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 chemical depends on the species of predator or parasite, environmental conditions, and application rate.
5 Ratings are as follows: I-Do not apply to blooming plants; II-Apply only during late evening; III-Apply only during late evening, night, or early morning; and IV-Apply at any time with reasonable safety to bees. For more information, see How to Reduce Bee Poisoning From Pesticides (PDF), Pacific Northwest Extension Publication PNW591.
6 Duration: Short means hours to days; moderate means days to 2 weeks; and long means many weeks or months.
7 If rate is 0.025 lb a.i./acre, rating is II.
8 May cause flare-ups of spider mite populations.
9 Acute toxicity low, but reproductive capacity impacted.
10 If rate is less than 0.04 lb a.i./acre, rating is III; if 0.04 lb a.i./acre, rating is II; if 0.06 lb a.i./acre, rating is I.
11 Kills lady beetles.
12 If rate is 0.05 lb a.i./acre or less, rating is III.
13 If rate is 0.5 lb a.i./acre or less, rating is III.
14 If rate is 0.02 lb a.i./acre, rating is II.
15 Rating depends on rate used.
16 Residual is moderate if solution is between pH of 7 to 8.



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Pear
UC ANR Publication 3455

General Information

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.

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