Protecting Honeybees From Pesticides
E-494 (Revised), June, 1990
Reviewed and reprinted September 1997
Dean K. McBride, Extension Entomologist
Grower Precautions
Applicator Precautions
Beekeeper PrecautionsRelative toxicity of pesticides to honey bees determined by laboratory and field tests:
Beekeeping is an important industry in North Dakota. Bees produce honey and they are equally important as pollinators so they aid in the production of fruits, vegetables, legume seeds and pasture crops.
The honey bee is the only insect that can be moved quickly and in the desired numbers to effect the pollination of cultivated crops, commercial gardens and orchards.
Many pesticides used to control weeds, plant diseases and insects can be poisonous to bees and other beneficial insects. Most insecticides are especially injurious.
Fortunately, pesticides and other agricultural chemicals are not incorporated into the honey. Bees that collect pesticide-contaminated nectar or pollen usually die away from the hive. If foraging bees return to the hive with contaminated nectar or pollen, there are natural provisions that protect the honey from contamination. Bees will usually leave the hive if they become poisoned. Pollen is stored in combs for feeding the brood (young bees). Contaminated pollen may kill the nurse bees and the brood.
Colonies of bees can be affected severely by improper use of pesticides. It may require several weeks before the working force (field bees) can return to suitable numbers. This can reduce honey production, especially if the bees are killed during a heavy nectar flow. To protect bees and other beneficial insects, always use the safest recommended pesticides.
Grower
Precautions
Use insecticides with low hazard to bees for pest control.
Farmers hiring an aerial applicator to spray their fields should alert beekeepers with hives in the intended spray area so they can take appropriate protective measures. Since the hives may have to be moved, the beekeeper should be given notice at least one to two days before spraying.
If hives cannot be adequately protected (moved or covered) before spraying begins, the aerial applicator should be alerted to the exact location of the hives so that they will not be contaminated by direct spraying or drift.
Timing of insecticide application is important. Never spray a crop in bloom unless it's absolutely necessary. If spraying a crop in bloom is necessary, do the spraying when there is minimal bee activity, preferably during the evening hours. During most summer evenings, honeybees leave fields by 8 p.m. and do not return until 8 a.m. or later the following day.
Hazards to bees can be reduced by controlling weeds in crop areas. Bees often forage on wild mustard and other weeds in bloom. Elimination of weeds will thus reduce bee kills during peak weed bloom.
All too frequently fields in North Dakota are sprayed unnecessarily with insecticides when insect population levels are not serious enough to warrant such treatment. Several sites in any given field should be accurately and carefully sampled to be absolutely sure that insect pest population levels are high enough to warrant control measures.
Applicator Precautions
Use insecticides that have low hazard to bees.
Timing of insecticide application: Never spray a crop in bloom unless it's absolutely necessary. If spraying a crop in bloom is necessary, spray when there will be minimal bee activity, preferably during the evening hours. Evening spraying also allows the insecticide to dry on the crop before bee activity begins the next morning.
Modify control programs according to weather. Cold temperatures prolong the residual of insecticide while warm temperatures break down insecticides more rapidly. Warm temperatures in late afternoon, early evening or early morning can "hold" bees in blooming fields for longer periods. Pay attention to wind direction and velocity in relation to nearby beeyard locations.
Applicators who are unsure of where beehives are located should find out by consulting with farmer-customers or contacting the state apiary inspector, North Dakota Department of Agriculture, in Bismarck. (Phone: 701/224-4997 or 701/224-2231)
When spraying close to beeyards when the hives cannot be moved or covered, use a drift reducing additive such as Nalco-Trol to minimize drift.
Bee research investigations in the state of Washington demonstrated that stickers such as Bond or Surstix will improve the safety of emulsifiable concentrate insecticides relative to bees (and other non-target organisms).
Beekeeper Precautions
If an insecticide with high toxicity to bees is to be used in an area where your bees are foraging, be prepared to take steps to reduce the poisoning risk:
Select an apiary location with low pesticide risk whenever possible.
Notify growers and commercial applicators in the area as well as the county agent and the office of the state apiary inspector at the North Dakota Department of Agriculture in Bismarck (phone: 701/224-4997 or 701/224-2231) of the exact location of your hives. Make sure your hive locations are registered with the North Dakota Department of Agriculture.
Make sure that your current address and phone number are legibly printed on your hives so that you can be quickly contacted prior to a pesticide spraying in the area of your apiary location.
Learn as much as you can about the pesticides being used in your area. If long residual pesticides with high bee toxicity are being applied to area crops, it may be best to move your hives out of the area if possible. The new site should be at least three miles away from the spray area.
If the pesticide being used has a short residual life, you may be able to confine your bees until the danger has passed. Be sure the hive does not overheat if you choose this method.
Pollen traps may help reduce the amount of contaminated pollen admitted to the hives and thus minimize losses.
Get to know the aerial applicators that spray near your beeyards. They are as interested in protecting your bees as you are.
Table 1. Relative toxicity of pesticides to honey bees determined
by laboratory and field tests.
(CALIFORNIA, 1950 through 1980) (Number-keyed notes on their uses can be found at the end of this section)
Group 1 -- Highly toxic:
Severe losses may be expected if used when bees are present at treatment time or within a day thereafter, except where noted to the contrary.------------------------------------------- Pesticides (trade name and/or common name) ------------------------------------------- aldrin2 Ambush� 2,18, permethrin arsenicals 1,2 Asana�, esfenvalerate Avermectin� 17 Azodrin� 1,2, monocrotophos Baygon� 2, propoxur Baytex� 2, fenthion Bidrin� 1,2, dicrotophos Bux�, bufencarb carbosulfan 2, FMC-35001 Cygon� 2, dimethoate Cythion� 2,4, malathion Dasanit� 5, fensulfothion DDVP� 2, dichlorvos Dibrom� 2,3, naled Decis� 2, decamethrin De-Fend� 2, dimethoate diazinon 2, Spectracide� dieldrin 1,2 Dimecron� 2, phosphamidon Dursban� 2, chlorpyrifos Ekamet�, etrimfos EPN 1,2 Ethyl Guthion�, azinphos-ethyl Famophos�, famphur Ficam�, bendiocarb Folithion�, fenitrothion Furadan� 2,5, carbofuran Gardona� 1,2, stirofos Guthion� 1,2, azinphos-methyl heptachlor 1,2 Imidan� 2, phosmet Lannate� 2, methomyl Lorsban�, chlorpyrifos malathion 2,4 Matacil�, aminocarb Mesurol�, methiocarb methyl parathion 1,2,11,12 Monitor� 2, methamidophos Nemacur� 5, fenamiphos Nudrin� 2, methomyl Orthene� 2, acephate parathion 1,2 Pay-Off� Phosdrin� 1,2,3, mevinphos phosphamidon 2, Dimecron� Pounce� 2,18, permethrin Pydrin� 2, fenvalerate resmethrin, Synthrin� Sevin� 2, carbaryl Spectracide 2, diazinon Sumithion�, fenitrothion Sumithrin�, d-phenothrin Supracide� 2, methidathion Tamaron� 2, methamidophos Temik� 1,2,5,7, aldicarb tepp 1,2,3 Vapona� 2, dichlorvos TM -------------------------------------------
Group II -- Moderately toxic:
Can be used around bees if dosage, timing, and method of application are correct, but should not be applied directly on bees in the field or on the hives.-------------------------------------------------- Insecticides (trade name and/or common name) -------------------------------------------------- Abate� 2, temephos Agritox�, trichloronate Bolstar�, sulprophos Carzol� 2, formetanate hydrochloride chlordane 2 Ciodrin�, crotoxyphos Counter�, terbufos Croneton�, ethiofencarb Curacron�, profenofos DDT 1,2,10 Di-Syston� 1,2,6,18, disulfoton Dyfonate�, fonofos endrin 1,2 Korlan�, ronnel Larvin� 2, thiodicarb Metasystox-R� 2, oxydemeton-methyl Mocap�, ethoprop Perthane�, ethylan Pyramat� Sevin� 4-Oil2, carbaryl Sevimol� 2, carbaryl Syston� 1,2,18, demeton Thimet� 1,2,6, phorate Thiodan� 2, endosulfan Trithion� 2, carbophenothion Vydate� 2, oxamyl Zolone�, phosalone --------------------------------------------------
Group III -- Relatively nontoxic:
Can be used around bees with minimum injury.------------------------------------------------------------- Insecticides and Acaracides (trade name and/or common name) ------------------------------------------------------------- Acaraben�, chlorobenzilate allethrin, Pynamin� Altosid� 17, methoprene Baam�, amitraz Bacillus thuringiensis 17, Bactur� Bactospeine�, Bakthane�, Dipel�, Thuricide� Birlane�, chlorfenvinphos Comite�, propargite cryolite 2, Kryocide� Delnav�, dioxathion Dessin�, dinobuton Dimilin� 17, diflubenzuron Dylox� 2, trichlorfon ethion Fundal�, chlordimeform Galecron�, chlordimeform Heliothis polyhedrosis virus Kelthane� 1, dicofol Mavrik� 2, fluvalinate methoxychlor 2, Marlate� Mitac�, amitraz Morestan�, oxythioquinox Morocide�, binapacryl Murvesco�, fenson nicotine 2 Omite�, propargite Pentac�, dienochlor pirimor� 2, pirimicarb Plictran� 2, cyhexatin pyrethrum (natural) rotenone 2 sabadilla 2 Sayfos�, menazon Sevin�, SL2, carbaryl Sevin� SLR2, carbaryl Smite�, sodium azide Tedion�, tetradifon Tetram� Tokuthion�, prothiophos Torak�, dialifor toxaphene 1,2 Zardex�, cycloprate ------------------------------------------------------------- Fungicides (trade and/or common name) ------------------------------------------------------------- Afugan� 2, pyrazophos Arasan�, thiram Bayleton�, triadimefon Benlate�, benomyl Bordeaux mixture 2 Bravo�, chlorothalonil captan 11 copper oxychloride sulfate copper 8-quinolinolate copper sulfate cuprex�, dodine cupric oxide cupric hydroxide, Kocide� Delan�, dithianon Dessin�, dinobuton Difolatan�, captafol Dithane� D-14, nabam Dithane� M-22, maneb Dithane� M-45, manzeb Dithane� Z-78, zineb Du-Ter�, fentin hydroxide Dyrene�, anilazine ferbam glyodin Hinosan�, edifenphos Indar�, butrizol Karathane�, dinocap Lesan�, fenaminosulf Morestan�, oxythioquinox Morocide�, binapacryl Mylone�, dazomet Phaltan�, folpet Plantvax�, oxycarboxin Polyram�, metiram Ridomil� Sisthane�, fenapanil Smite�, sodium azide sulfur 2 Thiram, Thylate� Thyfural Vitavax�, carboxin ziram, Zerlate� ------------------------------------------------------------- Herbicides, Defoliants, and Desiccants (trade and/or common name) ------------------------------------------------------------- Aatrex�, atrazine Alachlor Alanap�, naptalam Alopex�, clofop-isobutyl Amex� 820, butralin Amiben�, chloramben amitrole Ammate�, AMS Aquathol K�, endothall, dipotassium Avenge�, difenzoquat Balan�, benefin Banvel, dacamba Basagran�, bentazon Basalin�, fluchloralin Betanal�, phenmedipham Betanex�, desmedipham Bladex�, cyanazine Blazer�, acifluorfen butachlor butam cacodylic acid 1 Cambilene� 1, 2.3.6-TBA Caparol�, prometryn Casoron�, dichlobenil Chloro IPC�, chlorpropham Cotoranr, fluometuron 2,4-D 1,2 DEF� 8 Desiccant L-10� 1,9, arsenic acid Devrinol�, napromamide Dichlorprop 1, 2.4-DP dinoseb 9, dinitrobutylphenol diquat 8,9 Dual�, metalachlor endothall, sodium salt, Accelerate� Eptam�, EPTC Eradicane�, EPTC+safener Evik�, ametryn Evital�, norflurazon Folex� 1,8, merphos Garlon�, triclopyr Goal�, oxyfluorfen Hoelon�, diclofop-methyl Hydrothol 191�, endothall monopotassium salt Hyvar�, bromacil Igran�, terbutryn IPC�, propham Karmex�, diuron Kerb�, pronamide Lasso�, alachlor Lorox�, linuron Maloran�, chlorbromuron MCPA 1 Methar� 1, DSMA Milogard�, propazine Modown�, bifenox MSMA 1 Mylone�, dazomet Nortron�, ethofumesate Paarlan�, isopropalin paraquat 1,9 Planavin�, nitralin Pramitol�, prometon Preforan�, fluorodife princep�, simazine Probe�, methazole Prowl�, pendimethalin Ramrod�, propachlor Randox�, CDAA Ronstar�, oxydiazon Roundup�, glyphosate Sancap�, dipropetryn Sencor�, metribuzin silvex 1, 2.4.5-TP Sinbar�, terbacil Smite�, sodium azide Surflan�, oryzalin Sutan� +, butylate 2.4.5-T 1,2 Telvar�, monuron Tenoran�, chloroxuron TOK�, nitrofen Tolban�, profluralin Tordon�, picloram Treflan�, tribluralin Turf Herbicide�, endothall, disodium Vegadex�, CDEC Zorial�, norflurazon ------------------------------------------------------------- Nematicides and Miscellaneous (trade and/or common name) ------------------------------------------------------------- endothall 13 Exhalt�800 14 gibberellic acid 13 Mocap� 5, ethoprop Mylone� 5, dazomet N-Serve� 15, nitrapyrin Polaris� 16, glyphosine Smite� 5, sodium azide Sustar� 13,16 -------------------------------------------------------------
Number-keyed Notes on Pesticide Use
- California state regulations require permits for most uses of these chemicals, also for 2,4-D and 2,4,5-T as herbicides but not as sprays on citrus.
- Laboratory- and field-tested mainly on alfalfa, citrus, cotton, ladino clover, milo and sweet corn; all other chemicals were laboratory-tested only.
- Dibrom�, Phosdrin�, and tepp have such short residual activity that they kill only bees contacted at treatment time or shortly thereafter. Usually safe to use when bees are not in flight; not safe to use around colonies.
- Malathion has been applied on thousands of acres of alfalfa in bloom without serious loss of bees. However, occasional heavy losses have occurred, particularly under high temperature conditions. If applied to alfalfa in bloom it should be only as a spray, and application should be made during the night or early in the morning when bees are not foraging in the field. Undiluted technical malathion spray (ULV) should not be used around bees.
- Nematicide.
- Di-Syston� (disulfoton) and other systemic pesticides used as seed treatments have not caused bee losses.
- Temik� (aldicarb), although highly toxic to bees as a contact poison, is used only in granular form, and extensive field usage has not caused bee losses.
- Defoliant.
- Desiccant.
- DDT has been withdrawn for most uses in U.S.A.
- Field doses have caused brood damage.
- The microencapsulated formulation of methyl parathion, known as Penncap-M� is highly toxic to foraging bees, young hive bees, and brood. Overall, it is 13 times more hazardous to honey bees than the EC (emulsifiable concentrate) formulation. Penncap-M� is too hazardous to be applied to any area or within 1 mile of any area where and when bees are present.
- Plant growth regulator.
- Sticker/extender.
- Nitrification inhibitor.
- Chemical ripener.
- Insect growth regulator.
- Honey bee repellent.
E-494 (Revised), June 1990
Reviewed and Reprinted September 1997
