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Varroacides and their residues in bee productsKlaus Wallner

To cite this version:Klaus Wallner. Varroacides and their residues in bee products. Apidologie, Springer Verlag, 1999, 30(2-3), pp.235-248. <hal-00891581>

Review article

Varroacides and their residues in bee products

Klaus Wallner

Universität Hohenheim, Landesanstalt für Bienenkunde, August-von-Hartmann-Str. 13,70593 Stuttgart, Germany

(Received 17 September 1998; accepted 17 February 1999)

Abstract - In general, the use of varroacides in bee colonies leaves residues in various bee products.Among the variety of available varroacides, three ingredients are commonly detectable in honeyand beeswax: bromopropylate (Folbex VA Neu), coumaphos (Perizin, Asuntol) and fluvalinate(Apistan, Klartan, Mavrik). These chemicals are fat-soluble and non-volatile, and thus they accumulatein ppm levels as residues in beeswax with years of treatment. Through the process of diffusion,these ingredients migrate from the wax comb into the stored honey. In German honey, the most fre-quently found varroacide is coumaphos (28 %). Bromopropylate is detectable but with decreasing fre-quency (11 %). Because of its high binding strength in beeswax, fluvalinate detection is relatively rarein honey (1 %). All residues were found with low ppb levels. Other ingredients with similar chemi-cal behaviour presently play an unimportant role as residues in honey, beeswax and propolis owingto the very low amount of ingredients used (acrinathrine, flumethrine) or instability (amitraz).&copy; Inra/DIB/AGIB/Elsevier, Paris

Apis mellifera / varroacides / bee products / residues

1. INTRODUCTION

In many parts of the world, the threat ofinfestation by the parasitic mite, Varroajacobsoni Oud. (Acari: Varroidae), forcesbeekeepers to treat their colonies withacaracides. Currently, there are many prepa-rations and procedures available to treat themite. The substances that can be used astreatments vary depending on their nationalregistration. The discrepancies in the regu-

lation of treatments among various coun-tries causes much confusion, particularlyamong beekeepers. What beekeepers findespecially frustrating is that residues fromactive ingredients are tolerated in importedhoney in the same country where these sameingredients are prohibited for use as treat-ments. Since it is the purpose of these reg-ulations to protect the users and consumers,an international standard among national

regulations is needed.

E-mail: bienwa@uni-hohcnheim.de

Beekeepers and various industries ben-efit from the healthy and pure image thatbee products present to the public. To protectthis image, it is important to minimize oreliminate the residues of varroacides leftbehind in products in which purity and qual-ity is expected. As food, honey must not fallshort of this good image. In the cosmeticand pharmaceutical industries, beeswax isused extensively. Naturally, residues ofinsecticides or acaricides would not be

acceptable in propolis, which is used inmedicine for people in many countries.

2. ANALYTICAL CAPABILITIES

Inevitably, each treatment with acaracidesleaves behind residues in the bee hive. Theirdetection depends on several factors, includ-ing the amount of active ingredient used,the chemical behaviour and, of course, theanalytical capabilities in the laboratory.Many efforts have been made by scientiststhroughout the world to establish sensitiveanalytical methods for the detection of var-roacides in honey and beeswax [1, 3, 11,16, 18, 29, 42, 47, 48-49, 54, 61, 68]. Thedetection limits of the varroacides in honeyare low (ppb levels < 10). In beeswax, theyactually can be detected with levels around0.1 ppm.

The detection of ingredients that occurnaturally in honey (e.g. formic acid, lacticacid, oxalic acid, essential oils) is difficult.These substances cannot be clearly identifiedas a residue. When treatments are appliedaccording to recommendations [24, 33], thedetected values fall within the same range asthe natural variation in honey [12, 31, 36,39, 45, 46, 57]. Therefore, a regular check ofthe residue level is not required. For thesereasons, beekeepers would find these ingre-dients to be very suitable as varroacides. Onthe other hand, residues of synthetic insec-ticides or acaricides can be clearly identi-fied, and as they are foreign substances inhoney they have to be evaluated toxicolog-ically. Independent of the residue values,these synthetics generally damage the imageof honey and other bee products.

3. AMOUNTOF THE ACTIVE INGREDIENT

When impregnated carriers are insertedinto the hive, the amounts of active ingre-dients in the strips can vary enormouslyamong different formulations (table I). Theprecise amount of substance that is releasedper unit of time is unknown and may differbetween treatments. The analysis of Apistanstrips before and after use in colonies con-firmed that only a fraction of the active

ingredient in the strips would be sufficientfor treatment [22]. The amount of substancefinally distributed throughout the colonydepends on the amount of active ingredientimpregnated in the strip, on the activity ofthe bees and on the duration of the applica-tion. The more of the active ingredient astrip contains and the longer it is in contactwith bees, the greater is the distribution ofthe ingredient within the colony and thehigher the risk of measurable residues. Car-riers with small amounts of active ingredientdo not leave measurable residues in

beeswax, even with excessively long appli-cations. For this reason, residues of fluvali-nate (Apistan) in wax can be found very often[14, 17, 40, 67] but residues of flumethrine(Bayvarol) or acrinathrine (Gabon PA) arefound only rarely [5, 55, 64].

Acaricides which are used with similar

efficacy as drip solutions (liquid formationsthat are dripped directly onto the bees) bringdifferent amounts of ingredient into the beehive [32]. Table I shows the amounts used ofsome more widely used acaricides, such as

Apitol, Perizin and Klartan or Mavrik(0.01 %). When the amount of ingredientincreases, the risk of measurable residuesalso increases. Treatments with Apitol reg-ularly create residues in honey at levels ofaround 100 ppb. When Klartan/Mavrik sus-pensions are used, detectable residues arevery rare [59].

4. CHEMICAL BEHAVIOUR

The active ingredients of varroacides canbe divided by into two main groups: thewater-soluble (hydrophilic) and the fat-sol-uble (lipophilic) ingredients (table II).

4.1. Water-soluble chemicals

Water-soluble, active ingredients suchas formic acid [45, 46], oxalic acid [39] andcymiazole [ 19, 60] endanger the quality ofhoney since these substances are dilutedeasily in honey. The use of these substancesduring the nectar flow always results in con-

siderable residues. Organic acids may alsoimpart a false taste to the honey. The honeyharvest or consumption of honey by bees inthe colony reduces the available amount ofsubstance in the hive. However, volatileresidues such as formic acid decrease instored food and extracted honey over time[12, 45]. Water-soluble ingredients have nonegative long-term effect on beeswax qual-ity since they are not stored in beeswax.Therefore, an accumulation of such sub-stances in the wax does not occur.

4.2. Fat-soluble,stable, active ingredients

The situation is different in the case offat-soluble substances. First of all, theseingredients are stable and increase in thewax comb. From the wax, they migrate intothe stored honey. Laboratory samples giventhe same conditions as in the bee colonyshowed this migration clearly [58]. Thehigher the concentration in the wax, themore residues that could be detected in the

honey. Another negative effect is the con-tamination of wax particles in the honey[63]. Contaminated wax is a significantsource of residues in honey because a natu-ral degradation of varroacides in beeswaxdoes not occur. Rather, there is an accumu-lation due to repeated applications. Thecapacity of beeswax is enormous and therecycling of old combwax into foundationsdoes not change the content of the activeingredient [5]. Also, the technical capabili-ties for cleaning of wax are limited [56, 63].Only the complete destruction of beeswax,by burning the wax as a candle for exam-ple, can destroy the stored ingredients [66].Therefore, residues are detectable and thequality of the wax is permanently damagedin beeswax from all countries where thesesubstances are used. In summary, fat-solu-ble ingredients, especially when they arestable and non-volatile, represent a greatrisk in apiculture of long-term residue accu-mulation.

4.3. Fat-soluble, volatileor unstable active ingredients

Within the group of fat-soluble active

ingredients, there are varroacides whoseconcentration can decrease in beeswax. Thisdecrease is because they contain semi-volatile ingredients such as essential oils(e.g. thymol, wintergreen oil), and othersubstances, which can decay into metabo-lites (e.g. amitraz). During the application ofthe treatment, only some of the semi-volatileingredients attach to the wax, while a major-ity evaporates because of the temperatureof the hive [25]. As a result, the amountactually left in the wax is effectivelyreduced. Although, an accumulation ofresidue does not occur during the years ofapplication, traces remain detectable in hon-eycomb [6]. The amount of the ingredientcan also be effectively reduced during therecycling of old wax into foundations, if thewax is not only liquefied but also steamed.

4.4. Amitraz is metabolized

A well-known representative of unsta-ble, fat-soluble varroacides is amitraz, whichhas been used in several countries for manyyears. Amitraz is not stable in honey, andso almost completely degrades into severaldecomposed metabolites after 3-4 weeks[3, 27]. Therefore, all efforts to detect ami-traz residues in honey have been unsuc-cessful [3, 10, 18, 34]. Amitraz also doesnot remain stable in beeswax. Conversely,beeswax seems to have an acceleratingeffect on the degradation of amitraz. Exper-iments with amitraz and bromopropylate onplates of aluminium foil and beeswaxshowed that amitraz on beeswax disappearswithin hours. Both ingredients were dis-solved in acetone-hexane (1:1) with a con-centration of 1 ng·&mu;L-1. A series of thinbeeswax and aluminium plates were stampedout and 5 &mu;L of the solution were deliveredthrough pipettes onto each plate. After a cer-tain time, the plates were placed with 1 mL

acetone-hexane into vials with seals. Thebeeswax plates dissolved completely aftershaking the vial. The analysis of the solutionand the calculation were performed with aShimadzu GC-MS QP 5050 system.

Figure I shows the rapid breakdown ofamitraz on the beeswax plates. The activeingredient decays with room temperatureinto known metabolites, mainly into the poi-sonous, volatile 2.4 dimethyl-aniline. Asexpected, the substance, bromopropylate,remained stable on both materials. Highertemperatures, which are common in foun-dation production, accelerate this degrada-tion significantly. Therefore, an increase inamitraz in beeswax during the years of appli-cation can be excluded. Amitraz remainsstable for months within other materials,such as aluminium foil or organic solvents.

5. DISTRIBUTION OFVARROACIDES IN THE BEEHIVE

Fat-soluble ingredients are distributedthroughout the colony by the bees’ legs andbodies. All inner surfaces of the hive thatare walked on by bees, such as the frames,

bottoms and covers, are coated with a verythin layer of wax. Lipophilic substances arestored there and may pass in measurableamounts into other bee products such as vir-gin wax and propolis. Therefore, it is not

important in which form the substance wasinitially inserted into the bee hive. Smokestrips (Folbex VA Neu, Amitraz), or otherdiffusers, distribute the ingredient duringapplication, covering the entire interior ofthe bee hive with a fine film composed ofthe substance. This includes open brood,stored pollen and uncapped nectar.

By using carriers, the active ingredientis only inserted into limited areas of the hive.Within a short time, the bees distribute thissubstance throughout the whole hive [67].This very rapid distribution was discoveredusing radioactive marked wax [13] and con-firmed with combs from fluvalinate- orflumethrine-treated colonies, which retaineda varroacide effect in untreated colonies [9,38]. Experiments with swarms from untreatedcolonies, which were placed in used hivebodies without foundation, showed measur-able amounts of bromopropylate in the combwax after a few weeks [8].

Fat-soluble treatments such as coumaphosor fluvalinate can be detected in stored orextracted honey when beekeepers use dripsolutions. The risk of residue accumulationis correlated with the amount of the ingre-dient used and the number of applicationsduring the year. Drops of the suspensionunavoidably land in open cells and con-taminate the cell contents directly. Only24 % of an applied coumaphos drip solu-tion were found to reach the alimentarycanal of bees, the rest of the solutionremained in other places in the bee hive[52]. Furthermore, another method ofresidue accumulation has been observed

during bee intoxication caused by plant-pro-tective agents. When bees make contact withpoisonous substances, they react by signif-icantly increasing their food intake [62],which decreases the concentration of theactive substance in the honey sac and thusweakens the poisonous effect. After a certaintime, the bees regurgitate a portion of thecontaminated food into the cells, causingthe remaining cell contents and the cell wallsto come into contact with the treatment.

Bees which mature and live in contami-nated hives contain varroacides in the fattissue of their bodies and on the surface oftheir bodies [65]. Swarms that originate fromcoumaphos-treated colonies with levels ofcoumaphos around 15 mg·kg-1 in the waxsecrete virgin wax that has residues withlevels of more than 1 mg·kg-1. Similar resultswere shown from experiments with coloniesthat produced contaminated wax 6-18 monthsafter the last treatment with coumaphos [53].

6. RESIDUES IN HONEY

Honey analysis in different laboratoriesshowed that, with few exceptions, residuesof the stable, lipophilic treatments can befound. Up to now, the following varroacideshave been detected with ppb levels in honey:bromopropylate [7, 23, 29, 44, 57, 59],coumaphos [15, 21, 29, 50, 57, 59], fluvali-nate [7, 14, 59], malathion [2, 50], diazinon

[21], chlordimeform [28] andcymiazole [19].

Since 1988, long-term studies have beencarried out at the University of Stuttgart-Hohenheim, in which up to 1 000 honeysamples are analysed per year within thescope for general quality control. In Germanhoney, residues of three synthetic varroacidesare detectable. They all belong to the groupof non-volatile, fat-soluble substances.

6.1. Bromopropylate(Folbex VA Neu)

Although this ingredient has not beenused in Germany for 8 years, in approxi-mately 11 % of German honey bromo-propylate residues can be found in amountsof 2-10 ppb. In 1996, the percentage of pos-itive samples was 17.4 %, and in 1995 was20.2 %. Without exception, these residuescome from accumulation of the active ingre-dient in wax combs, on frames and hivewalls, and from foundation made from con-taminated wax. Ever since the high residuerisk of this treatment was recognized, Ger-man beekeepers voluntarily discontinuedits use. However, Folbex VA Neu is stillregistered. In the past, residues of bromo-propylate were detected in honey with lev-els above 100 ppb.

6.2. Coumaphos (Perizin/Asuntol)

Today, Perizin is the most frequentlyused drip solution in German apiaries. It ismainly used during the wintertime incolonies without brood, but sometimes it isalso used in late summer in multiple treat-ments in colonies with brood. Coumaphosrepresents the most frequently detectablevarroacide in honey. In 1997, approximately28 % of examined honey were contaminatedwith levels between 2 and 15 ppb. Similarresidue levels were found in 1995 and 1996in 24.5 and 31 % of the analysed samples,respectively.

6.3. Fluvalinate

(Klartan/Mavrik/Apistan)

Fluvalinate belongs to the group of syn-thetic pyrethroids. It is used for control ofV. jacobsoni worldwide [35, 51]. Impreg-nated carriers are inserted into the colonywith amounts of fluvalinate in grams. In

drip solutions, the necessary amount ofingredient is extremely low in comparison toother systemic varroacides (coumaphos,cymiazole) (table I). Residues in Germanhoney are found only rarely when mistakesoccur in the application and/or in the prepa-ration of the drip solution, and if residuesin the wax are at a high level after severalyears of application. In these instances, thesubstance migrates by diffusion from thecomb into the honey. Fluvalinate can befound in 1 % of honey produced in Ger-many with residue levels between 2 and7 ppb. Higher amounts reaching 40 ppbwere found in honey from eastern Europe,and are also reported from other countries[30]. Recently, fluvalinate-resistant miteshave appeared in several countries, whichindicate that the continued use of the whole

group of synthetic pyrethroids is question-able [37, 51]. The remaining synthetic var-

roacides play a subordinate role in residuesin German honey.

There are few publications on the stabil-ity of residues in honey. In laboratory testswith spiked honeys, a reduction of over90 % of coumaphos and malathion residueswas found after storage for 3 months [50]. Inthe case of fluvalinate, similar observationswere made, as well as the observation thatthese substances degrade into severalmetabolites [26]. Nevertheless, there is noconfirmation of this described rapid insta-bility of coumaphos and fluvalinate in honeyin the long-term studies at Stuttgart-Hohen-heim.

6.4. National regulations

For consumer protection, the acceptableresidue levels in honey are determinednationally (MRL: maximum residue levels)and influence the procedures for checkingfood in individual countries. National regu-lations are not homogeneous (table III)which causes problems in the internationalmarketing and trade of honey. Generally,the permitted residue levels of synthetic var-roacides in honey are very low; although

honey consumption is considerably lowerthan other foods, in which higher levels aretolerated (e.g. meat and vegetables). Har-monization of these permitted levels is beingplanned currently among European coun-tries and perhaps others as well [41].

7. RESIDUES IN WAX

Most of the fat-soluble substances, withthe exception of amitraz, are widely usedas varroacides and can be found with ppmlevels in beeswax. Up to now, the followingvarroacides have been detected in wax: bro-

mopropylate [4, 23, 44, 57, 67, 64], couma-phos [15, 53, 57, 64, 67, 68], fluvalinate [7,14, 17, 30, 34, 43, 64], flumethrine [5] andtetradifon [64].

Because of the very small amount of sub-stance used, levels of acrinathrine andflumethrine in beeswax from apiaries canbe expected to be below the detection limitof most laboratories. Since 1993, 300-400beeswax samples have been analysed peryear at the University of Hohenheim. Mostof these samples were received directly frombeekeepers.

7.1. The current situation

The situation is not homogeneous, sincebeekeepers’ concepts of treatments can varygreatly. The active ingredients listed in theabove paragraph are detectable in beeswaxand as residues in honey. The measured val-ues of bromopropylate, coumaphos and flu-valinate are in the ppm area (detection lim-its 0.5 mg·kg-1). More than 90 % of theexamined local samples are contaminated.Often several of these varroacides can befound in the same sample. However, there isan increasing number of beekeepers whohave stopped using fat-soluble ingredientsand use organic acids exclusively. No resi-dues can be found in the wax of these api-aries, provided that residue-free foundationis used.

Table IV shows summarized results ofthe wax analyses for the year 1997 with acomparison of the situation in national andinternational apiaries. As expected, Germanwax is contaminated with high percentagesof bromopropylate (54.9 %) and coumaphos(61.0 %). A large number of samples con-tains amounts between 1 and 5 ppm. On theother hand, more than half of the interna-tional samples (55.0 %) are contaminated

with fluvalinate. This active substance canalso be found with increasing frequency inGerman wax. In 1996, the percentage of pos-itive samples was 23.6 % and in 1995 only13.2 %. Similar frequencies with slightlyhigher levels were shown in other countries[7, 14, 34, 40]. As a fat-soluble, non-volatilesubstance, fluvalinate plays the chief role asa residue-creating substance in beeswax.

The same frequencies are also found inwax foundation on the national and foreignmarket, as beeswax is an internationallytraded product. Additional ingredients,which are unknown as varroacides in Ger-

many (e.g. tetradifon), reach the apiaries viafoundation produced from imported wax.A clear difference can be seen in the com-

parison of foundation produced from Ger-man or foreign wax. As expected, residuesof bromopropylate (0.5-10 mg·kg-1) andcoumaphos (0.5-3.5 mg·kg-1) can be foundin a high percentage (both 62.5 %) in foun-dation from wax produced in Germany.These ingredients are rarely found inimported wax (1.7 %) and are rare in foun-dation from foreign countries (1 and 20 %,respectively). In foreign foundation, fluvali-nate is quite often detectable with similarresidue values in the range 0.5-3.5 mg·kg-1.Within 26 examined samples, five were freeof measurable varroacides. These samplescame from New Zealand, Denmark, Uruguayand Africa.

In general, residues of varroacides inbeeswax are not regulated. With the excep-tion of the USA (fluvalinate: 6 ppm), noofficial limits exist. Since great amounts ofbeeswax are processed for pharmaceuticalpurposes or for the food and cosmetics

industries, pesticide residues are problem-atic. Several companies have created theirown internal maximum limits to which con-taminated beeswax is acceptable. Because ofthe easy migration of substances into honey,comb wax should have the least amount ofcontamination. To ensure that there is nomeasurable effect, residues in the waxshould be lower than 1 mg·kg-1 [63].

7.2. Biological effectsof residues in beeswax

The effect on mortality and fertility ofVarroa jacobsoni caused by acaricideresidues in beeswax was investigated [20].Field experiments with coumaphos- and flu-valinate-impregnated foundations (0, 1, 10,100 ppm) showed that there is a measurableeffect on the survival of mother mites,depending on the type and concentration ofthe acaricide. Coumaphos levels of over10 ppm in the wax comb killed a high per-centage of mites that went into the cells forreproduction. Fluvalinate showed theseeffects, but only in unrealistically high lev-els of around 100 ppm in the wax. Whenthe cell walls were covered with cocoons,both substances lost the described effect in

any of the tested concentrations. Obviously,the honeybee cocoon is an effective barrierthat prevents mites from entering the sealedcells. No negative effects on the bees or thebrood were observed during this experiment[20].

8. RESIDUES IN PROPOLIS

Few data exist on the influence of var-roacides on the quality of propolis. Propolisthat is mainly used in apitherapy should befree of measurable pesticides. The availabledata show that propolis has a high affinity tofat-soluble varroacides and is susceptible tocontamination. For example, bromopropy-late was detected with levels > 11 ppm afterfumigation [44] and fluvalinate had levels> 8 ppm [30], in single samples of morethan 50 ppm [63] after using Apistan strips.Alcoholic extractions of contaminated roughmaterial also contained residues, indepen-dent of the alcohol concentration (50-98 %).

9. CONCLUSION

The treatment of colonies againstV. jacobsoni influences the quality of beeproducts in many countries of the world.

Depending on the chosen varroacide, a vary-ing level of residues can be found in honey,beeswax and propolis. Discussions on thetoxicology of these residues are endless, asthe current official limits do not contributeto an objective consideration of the topic.In the future management of honeybees, it isimportant to consider that as soon as there isa choice between contaminated and residue-free products, consumers will choose thelatter.

The use of synthetic, lipophilic var-roacides in colonies should be minimized,and the use of organic acids or essential oilsincreased. It is also necessary to changehabits of recycling wax into foundation. Oldcombs that are contaminated should not beused for the production of foundation.Instead, foundation should be made fromvirgin wax and wax cappings. With anincreased production of virgin wax incolonies, a system to separate out contami-nated combs from the wax recycling pro-cess, and an efficient acaracide applicationsystem, residue levels in bee products can bemaintained below the detectable limits andfar below the maximum residue levels.

Résumé - Les varroacides et leurs rési-dus dans les produits du rucher. Les trai-tements contre l’acarien Varroa jacobsonipèsent actuellement sur la qualité des pro-duits du rucher dans de nombreux pays. Ladiscussion sur le caractère dangereux desrésidus porte atteinte à l’image positive qu’a le public de ces produits. Les désaccordsentre pays concernant la réglementation desproduits de traitement autorisés et les limitesmaximales admissibles (tableau III) necontribuent pas à dépassionner le débat.La nature chimique du varroacide et la quan-tité de substance appliquée peuvent énor-mément varier (tableaux I et II). Les sub-stances hydrosolubles (acides formique,lactique, oxalique) sont dangereuses pourla qualité du miel, puisqu’elles peuvent êtrediluées dans le miel. La cire accumule etstabilise les substances liposolubles qui peu-

vent ensuite migrer des rayons de cire dansle miel entreposé ou le polluer sous forme de

particules de cire.A quelques rares exceptions les varroacideslipophiles utilisés ont pu être retrouvés dans lemiel également (limite de détection < 10 ppb).Des données existent actuellement pour lesmatières actives (m.a.) suivantes : bromo-propylate, coumaphos, fluvalinate, mala-thion, diazinon, chlordimeform et cymia-zole.À l’heure actuelle des résidus de trois m.a.non volatiles et liposolubles sont principa-lement présents daans les miels allemands.Dans près de 11 % des miels allemands ontrouve des résidus de bromopropylate (Fol-bex VA Neu) dans les limites de 2-10 ppb ;ils provenaient tous sans exception de lam.a. qui s’était fixée dans les rayons à lasuite de traitements effectués les années pas-sées. Le coumaphos (Perizin) fournit lesrésidus les plus souvent détectés dans lemiel. Environ 28 % de tous les miels alle-mands en contenaient des résidus, de l’ordrede 2-15 ppb. On trouve des valeurs sem-blables dans les miels étrangers. En com-paraison le fluvalinate (Klartan, Mavrik,Apistan) apparaît rarement dans le miel.Environ 1 % des miels allemands présen-tent des résidus de fluvalinate et ce dans deslimites plus basses (2-7 ppb). Des quantitésde m.a. allant jusqu’à 40 ppb ont été retrou-vées dans des échantillons provenantd’Europe de l’Est. Les résidus d’amitrazsont instables dans le miel. L’amitraz se

décompose presque totalement en trois àquatre semaines en produits de dégradation.Dans la cire non plus la m.a. présente à l’ori-gine n’est pas stable (figure 1).Dans aucun autre pays à l’exception desÉtats-Unis (fluvalinate : 6 ppm), il n’existede limites supérieures fixées pour les résidusde varroacides dans la cire. Si l’on comparela situation de l’apiculture en 1997 en Alle-magne et dans les pays étrangers, il est évi-dent que l’on trouve des pourcentages plusélevés de bromopropylate (54,9 %) et decoumaphos (61,0 %) dans les miels alle-mands. La majorité des échantillons ren-

ferme des quantités de m.a. comprises entre1 et 5 ppm. En revanche plus de la moitiédes échantillons étrangers (55,0 %) sont pol-lués par le fluvalinate. La tendance à retrou-ver cette m.a. dans les miells allemands aug-mente : en 1996, 23,6 % des échantillonsétaient positifs contre seulement 13,2 % en1995 (tableau IV). Le commerce interna-tional de la cire fait apparaître d’autres m.a.inconnnues en Allemagne comme varroa-cides (par exemple, le tétradifon). Sur les26 cires gaufrées étudiées en 1997, seulescinq échantillons, provenant de Nouvelle-Zélande, du Danemark, de Finlande, d’Uru-guay et d’Afrique, étaient dépourvus de rési-dus quantifiables de varroacides.On ne dispose jusqu’à présent que de peu dedonnées concernant les résidus de varroa-cides dans la propolis. On a mis en évidence,parfois en quantités élevées, la présence derésidus de bromopropylate (> 11 ppm) et defluvalinate (> 50 ppm).Pour abaisser le pourcentage d’échantillonsde miel, de cire et de propolis pollués, il fautinclure les acides organiques et les huilesessentielles dans les méthodes de lutte. L’uti-lisation de varroacides liposolubles doit êtreminimisée et la production de cire viergeaccrue. La vieille cire polluée doit être reti-rée du circuit de la cire gaufrée. &copy; Inra/DIB/

AGIB/Elsevier, Paris

Apis mellifera / Varroa jacobsoni /acaricide / produits du rucher / résidu

Zusammenfassung - Varroabekämp-fungsmittel und ihre Rückstände in Bie-nenprodukten. Die Bekämpfung der Var-roamilbe beeinflu&szlig;t derzeit die Qualität derBienenprodukte in vielen Ländern. Die Dis-kussion über die Gefährlichkeit von Rück-ständen schadet dem Ansehen der Bienen-

produkte in der Öffentlichkeit. Die Un-stimmigkeiten zwischen den Ländern beider Regelung der zugelassenen Bekämp-fungsmittel und den zulässigen Höchst-grenzen (Tabelle III) sind für eine Ver-

sachlichung dieser Diskussion nicht geeig-net.

Der chemische Charakter der Varroazide undihre applizierten Substanzmengen könnensehr unterschiedlich sein. (Tabelle I und II).Wasserlösliche Wirkstoffe (Ameisensäure,Milchsäure, Oxalsäure) gefährden die Honig-qualität, da diese Substanzen von Honigleicht aufgenommen werden. FettlöslicheSubstanzen werden im Wachs gespeichertund stabilisiert. Aus dem Wabenwachs kön-nen sie in den eingelagerten Honig einwan-dern oder in Form von Wachspartikeln zubelastetem Honig führen.Mit nur wenigen Ausnahmen werden dieangewandten lipophilen Varroazide auchim Honig nachgewiesen (Nachweisgrenzen< 10 ppb). Daten liegen zu folgenden Wirk-stoffen vor: Brompropylat, Coumaphos, Flu-valinat, Malathion, Diazinon, Chlordime-form und Cymiazol.In deutschen Honigen treten derzeit

hauptsächlich Rückstände von drei nicht-flüchtigen, fettlöslichen Wirkstoffen auf: Inca. 11 % der deutschen Honige können imBereich von 2-10 ppb Brompropylat-Rück-stände gefunden werden. Diese Rückständestammen ausnahmslos aus dem Wirkstoff-

depot, das in den zurückliegenden Anwen-dungsjahren im Wabenwachs angelegtwurde.

Coumaphos (Perizin) stellt den am häufig-sten nachweisbaren Rückstand im Honigdar. Etwa 28 % aller untersuchten einhei-mischen Honige enthalten Rückstände inGrö&szlig;enordnungen von 2-15 ppb. Mit ähn-lichen Rückstandswerten wird Coumaphosauch in Auslandsproben gefunden.Fluvalinat (Klartan/Mavrik/Apistan) tauchtim Honig vergleichsweise selten auf. Etwa1 % der einheimischen Honige weisen Rück-stände im unteren ppb-Bereich (2-7 ppb)auf. Höhere Wirkstoffmengen bis 40 ppbwurden in Proben aus Osteuropa nachge-wiesen.

Amitraz-Rückstände sind im Honig nichtstabil. Amitraz zerfällt nach 3-4 Wochennahezu vollständig in verschiedene Abbau-produkte. Auch im Bienenwachs bleibt der

ursprünglich eingesetzte Wirkstoff nicht sta-bil (Abb. 1).Für Rückstände von Varroabekämpfungs-mitteln im Bienenwachs gibt es, mit Aus-nahme der USA (Fluvalinat 6 ppm) in kei-nem Land festgelegte Höchstgrenzen.Stellt man die Situation (1997) in den Imke-reien im In- und Ausland gegenüber, wirddeutlich, da&szlig; in hohen Prozentsätzen in deut-schem Wachs die Wirkstoffe Brompropy-lat (54,9 %) und Coumaphos (61,0 %) zufinden sind. Die überwiegende Zahl der Pro-ben enthält Wirkstoffmengen zwischen 1und 5 ppm. Dagegen ist mehr als die Hälfteder Auslandsproben (55,0 %) mit Fluvalinatbelastet. In deutschen Proben kann dieserWirkstoff mit zunehmender Tendenz gefun-den werden. 1996 betrug die Zahl der posi-tiven Proben 23,6 % und 1995 lediglich13,2%.Über den internationalen Wachshandel tau-chen zusätzliche Wirkstoffe auf, die inDeutschland als Varroazide unbekannt sind

(z.B. Tetradifon). Von den insgesamt 26 imJahr 1997 untersuchten internationalen Mit-

telwandchargen waren lediglich 5 frei vonme&szlig;baren Varroazidrückständen. DasWachs dieser Chargen kam aus Neuseeland,Dänemark, Finnland, Uruguay und Afrika.Bisher liegen nur wenige Daten zur Rück-standssituation von Varroaziden in Propolisvor. Nachgewiesen wurden Brompropylat(> 11 ppm) und Fluvalinat mit teilweise sehrhohen Rückstandsmengen (> 50 ppm).Um den Anteil der me&szlig;bar belastetenHonig-, Wachs- und Propolisproben zu sen-ken, müssen zukünftig vor allem die orga-nischen Säuren in die Bekämpfungskon-zepte aufgenommen werden. Auf deranderen Seite mu&szlig; der Einsatz von fettlös-lichen Medikamenten optimiert und die Pro-duktion von Jungfernwachs gesteigert wer-den. Kontaminiertes Altwachs mu&szlig; aus demKreislauf über Mittelwände herausgenom-men werden. &copy; Inra/DIB/AGIB/Elsevier,Paris

Apis mellifera / Varroabekämpfungsmittel /Bienenprodukte / Rückstände

REFERENCES

[1] Atienza J., Jimenez J., Bernal J.L., Martin M.T.,Supercritical fluid extraction of fluvalinateresidues in honey. Determination by high-per-formance liquid chromatography, J. Chromatogr.655 (1993) 95-99.

[2] Balayannis P.G., Santas L.A., Dissipation ofmalathion and fluvalinate residues from honey,J. Apic. Res. 31 (1992) 70-76.

[3] Bogdanov S., Bestimmung von Amitraz undseinen Metaboliten in Honig durch HPLC, Mit-teilung der Sektion Bienen 3 (1988) 1-9.

[4] Bogdanov S., Kilchenmann V., Acaricideresidues in beeswax: long-term studies inSwitzerland, Apidologie 26 (1995) 319-321.

[5] Bogdanov S., Kilchenmann V., Imdorf A., Acari-cide residues in beeswax and honey, in: Mizrahi A.,Lensky Y. (Eds.), Bee Products, Plenum Press,New York, 1997, pp. 239-246

[6] Bogdanov S., Imdorf A., Kilchenmann V.,Residues in wax and honey after Api Life VARtreatment, Apidologie 29 (1998) 513-524.

[7] Bogdanov S., Kilchenmann V., Imdorf A., Aca-ricide residues in some bee products, J. Apic.Res. 37 (1998) 57-67.

[8] Büchler R., Erzeugung von Naturbau undmögliche Auswirkungen auf die Volksentwick-lung, Allg. Dtsch. Imkerztg. 30 (1996) 20-23.

[9] Büchler R., Maul V., The after-effect of Bay-varol treatment in honey bee colonies on varroamites introduced later on, Apidologie 22 (1991)389-396.

[10] Bussiéras J., Goetz C., Weissenberger J., Essai detraitement au moyen d’amitraz sur support solide,Rev. Fr. Apic. 470 (1988) 23-26.

[11] Cabras P., Determination of cymiazole residuesin honey by liquid chromatograpy, J. Assoc. Off.Anal. Chem. Int. 76 (1993) 92-94.

[12] Capolongo F., Baggio A., Piro R., Schivo A.,Mutinelli F., Sabatini A.G., Colombo F., Mar-cazzan G.L., Massi S., Nanetti A., Trattamentodella varroasi con acido formico: accumulo nelmiele e influenza sulle sue caratteristiche, L’Apenostra amica 8 (1996) 4-11.

[13] Darchen R., La cire, son recyclage et son rôleprobable à l’intérieur d’une colonie d’Apis mel-lifica, Apidologie I 1 (1980) 193-202.

[14] De Greef M., De Wael L., Van Laere O., Bes-timmung der Rückstände von Fluvalinat in bel-gischem Honig und Bienenwachs, Allg. Dtsch.Imkerztg. 7 (1994) 7-8.

[15] De Lahitte J.D., A propos du Perizin, Santé del’Abeille 98 (1987) 54-61.

[16] De Paoli M., Taccheo B.M., Solid-phase extrac-tion and gas chromatographic determination offlumethrin residues in honey, Pestic. Sci. 34(1992) 61-63.

[17] Faucon J.P., Flamini C., Traitement de la var-roatose. Étude comparative de dispositifs à libéra-tion lente : essais préliminaires, Bulletin desGTV 1 (1989) 49-52.

[18] Fernández Muino M.A., Simal Lozano J., Gaschromatographic-mass spectrometric method forthe simultaneous determination of amitraz, bro-mopropylate, coumaphos, cymiazole and flu-valinate residues in honey, Analyst 118 (1993)1519-1522.

[19] Floris I., Papoff C.M., Prota R., Controllo autun-nale con Apitol di Varroa jacobsoni Oud. in unambiente mediterraneo, Apicoltura 10 (1995)33-42.

[20] Fries I., Wallner K., Rosenkranz P., Effects onVarroa jacobsoni from acaricides in beeswax,J. Apic. Res. 37 (1998) 85-90.

[21] Garcia M.A.F., Melgar M.J.R., Latorre C.H.,Fernandez M.I.G., Evidence for safety ofcoumaphos, diazinon and malathion, Vet. Hum.Toxicol. 36 (1994) 429-432.

[22] Gufler H.K., Wallner K., Apistanresistente Var-roamilben auch in Südtirol. Bienenwelt 37 (1995)165-166.

[23] Hansen H., Petersen J.H., Residues in honey andwax after treatment of bee colonies with bro-

mopropylate, Dan. J. Plant Soil Sci. 92 (1988)1-6.

[24] Imdorf A., Charrrière J.D., Alternative Var-roabekämpfung, Eidgenössische Forschun-gsanstalt für Milchwirtschaft, Bern, 1998.

[25] Imdorf A., Bogdanov S., Kilchenmann V.,Maquelin C., Apilife VAR: a new varroacidewith thymol as the main ingredient, Bee World76 (1995) 77-83.

[26] Jiménez J., Atienza J., Bernal J.L., Characteri-zation of fluvalinate residues in honey by gaschromatography, J. High Resol. Chromatogr. 18(1995) 367-372.

[27] Jiménez J., Bernal J.L., del Nozal M.J., Toribio L.,Characterisation and monitoring of Amitrazdegradation products in honey, J. High Resol.Chromatogr. 64 (1997) 81-84.

[28] Klein E., Rückstände des Akarizids Chlordime-form in Honig, Lebensm. Gerichtl. Chem. 43(1989) 86-93.

[29] Klein E., Weber E., Hurler E., Mayer L.,Gaschromatographische Bestimmung von Iso-propyl-4.4-Dibrombenzilat (Brompropylat),4.4-Dibrombenzophenon und verschiedenenAkariziden in Honig und Wabenwachs, Dtsch.Lebensm. Rundsch. 82 ( 1986) 185-188.

[30] Kubik M., Nowacki J., Michalczuk L., Pidek A.,Marcinkowski J., Penetration of fluvalinute intobee-products, J. Fruit Ornam. Plant Res. 1 (1995)13-22.

[31] Laub E., Metzler B., Putz A., Roth M., Zur Rück-standssituation zugelassener Varroatose-bekämpfungsmittel in Honig. Lebensm. Gerichtl.Chem. 4 (1987) 107-109.

[32] Liebig G., Varroaleitfaden, Landesverband Würt-tembergischer Imker, Stuttgart, 1990.

[33] Liebig G., Einfach Imkern, Gerhard Liebig,Stuttgart, 1998.

[34] Lodesani M., Pellacani A., Bergomi S., Carpana E.,Rabitti T., Lasagni P., Residue determinationfor some products used against Varroa infesta-tion in bees, Apidologie 23 (1992) 257-272.

[35] Lubinevski Y., Stern Y., Slazbezki Y., LenskyY., Ben-Yossef H., Gerson U., Control of Varroajacobsoni and Tropilaelaps clareae mites usingMavrik in Apis mellifera colonies und subtropi-cal and tropical climates, Am. Bee J. 128 (1988)48-52.

[36] Marx H., Stolle A., Zum gesundheitlichen Risikofür den Honigkonsumenten bei Behandlung einesBefalles mit Varroamilben mittels Oxalsäure,Amtstierärztl. Dienst Lebensmitt.kontr. 4 ( 1997)164-165.

[37] Milani N., The resistance of Vorroa jacobsoniOud to pyrethroids: a laboratory assay, Api-dologie 26 (1995) 415-429.

[38] Moosbeckhofer R., Ergebnisse aus Biotests überdie Langzeitwirkung von Apistan und Bayvarol,Bienenwelt 33 (1991) 149-154 and 179-181.

[39] Mutinelli F., Baggio A., Capolongo F., Piro R.,Prandin L., Biaison L., A scientific note on oxalicacid by topical application for the control of var-roosis, Apidologie 28 (1997) 461-462.

[40] Pechhacker H., Wallner K., Zur Rückstands-

frage im Rahmen dcr Varroabehandlung, Bienen-vater 111 (1991) 46-48.

[41] Piro R., European legislation for residues in beeproducts, in: 25th Int. Apicultural Congress,Antwerpen 1997, Apimondia Publ. House,Bucharest, 1999 (in press).

[42] Shcrma J., McGinnis S.C., Determination of

pentachlorphenol and cymiazole in water andhoney by C-18 solid phase extraction and quan-titative HPTLC, J. Liq. Chromatogr. 18 (1995)755-761.

[43] Slabezki Y., Gal H., Lensky Y., The effect offluvalinate applications in bee colonies on pop-ulations levels of Varroa jacobsoni and honeybees (Apis mellifera L.) and on residues in honeyand wax, BeeScience 1 (1991) 189-195.

[44] Stehr C., Wachendörfer G., Seeger H., Gaschro-matographische Rückstandsuntersuchungen aufBrompropylat bei Honig, Wachs und Propolisnach Anwendung von Folbex VA Neu im Rah-men der Varroatosebekämpfung, Tierärztl.Umsch. 51 (1996) 249-254.

[45] Stoya W., Wachendörfer G., Kary I., Siebentritt P.,Kaiser E., Ameisensäure als Therapeutikumgegen Varroatose und ihre Auswirkungen aufden Honig, Dtsch. Lebensm. Rundsch. 82 (1986)217-221.

[46] Stoya W., Wachendörfer G., Kary I., Siebentritt P.,Kaiser E., Milchsäure als Therapeutikum gegenVarroatose und ihre Auswirkungen auf denHonig, Dtsch. Lebensm. Rundsch. 83 (1987)283-286.

[47] Stricker O., Gierschner K., Vorwohl G., Gaschro-matographische Bestimmung von Brompropylat,4,4-Dibrombenzophenon, Coumaphos und Flu-valinat in Honig, Dtsch. Lebensm. Rundsch. 3(1989) 72-75.

[48] Taccheo M., De Paoli M., Spessotto C., Deter-mination of total amitraz residues in honey byelectron capture capillary gas chromatography -A simplified method, Pestic. Sci. 23 (1988)59-64.

[49] Taccheo M., De Paoli M., Spessotto C., Thedetermination of coumaphos residues in honeyby HPTLC with in-situ Fluorimetry, Pestic. Sci.25 (1989) 11-15.

[50] Thrasyvoulou A.T., Pappas N., Contamination ofhoney and wax with malathion and coumaphosused against the varroa mite, J. Apic. Res. 27(1988) 55-61.

[51] Trouiller J., Monitoring Varroa jacobsoni resis-tance to pyrethroids in western Europe, Api-dologie 29 (1998) 537-546.

[52] Van Buren N.W.M., Marien A.G.H., Vel-thuis H.H.W., The role of trophallaxis in the dis-tribution of Perizin in a honeybee colony withregard to the control of the varroa mite, Ento-mol. Exp. Appl. 65 (1992) 157-164.

[53] Van Buren N.W.M., Marien A.G.H., Vel-thuis H.H.W., Oudejans R.C.H.M., Residues inbeeswax and honey of Perizin, an acaricide tocombat the mite Varroa jacobsoni Oudemans,Environ. Entomol. 21 (1992) 860-865.

[54] Van Rillaer W., Bernaert H., Determination ofresidual bromopropylate and coumaphos inhoney and honey comb by capillary gas chro-matography, Z. Lebensm. Unters. Forsch. 188(1989) 135-137.

[55] Vesely V., Malonova H., Titera D., Acrinathrin,an effective varroacide and its residues in stores,

honey and wax, Apidologie 26 (1988) 321-322.

[56] Vesely V., Machova M., Hessler J., Hostomska V.,Lenicek J., Reduction of fluvalinate in beeswax

by chemical means, J. Apic. Res. 33 ( 1994)185-187.

[57] Wachendörfer G., Keding H., Beurteilung vonRückständen im Honig aus der Sicht deramtlichen Lehensmittelüberwachung nachAnwendung von Varroatose-Bekämpfungsmit-teln, Allg. Dtsch. Imkerztg. (1988) 414-421.

[58] Wallner K., Diffusion varroazider Wirkstoffeaus dem Wachs in den Honig, Apidologie 23(1992) 4.

[59] Wallner K., Varroabekämpfungsmittel - EineGefahr für den Honig, Die Biene 2 (1992) 61-67.

[60] Wallner K., Apitol-Zulassung - zwischen denZeilen gelesen, Allg. Dtsch. Imkerztg. 1 (1992)14-15.

[61] Wallner K., A method for determination of var-roacide residues in bees wax, Apidologie 24(1993) 502-503.

[62] Wallner K., Bienenschäden im Weinbau, Dr.Nienhaus Verlag, Stuttgart, 1994.

[63] Wallner K., The use of varroacides and theirinfluence on the quality of bee products, Am.Bee J. 12 (1995) 817-821.

[64] Wallner K., The actual beeswax quality in foun-dations on the market, Apidologie 28 (1997)168-170.

[65] Wallner K., Der Weg zur rückstandsfreien Imk-erei - Strategien aus der Sackgasse, Bienenvater118 (1997) 9-12.

[66] Wallner K., Kerzen aus Bienenwachs - einRisiko, Schweiz. Bienenztg. 121 (1998)760-764.

[67] Wallner K., Luh M., Womastek R., Pechhacker H.,Moosbeckhofer R., Entwicklung der Rück-standssituation am Institut für Bienenkunde seit

Beginn der Varroabehandlung, Bienenvater 116(1995) 320-329.

[68] Zimmermann S., Gierschner K.H., Vorwohl G.,Bestimmung von Brompropylat, 4.4-Dibromben-zophenon, Coumaphos und Fluvalinat inBienenwachs, Dtsch. Lebensm.-Rundsch. 11(1993) 341-344.