Medicina Veterinaria 2(1) 2003, 49-54 THE RE-USED APIFOS STRIPS IN VARROA DESTRUCTOR CONTROL BoŜena Chuda-Mickiewicz, Jarosław Prabucki, Jerzy Kazimierczak, Grzegorz PeruŜyński, Jerzy Samborski Abstract. The efficacy of varroosis control with Apifos strips used in the last year as well as with the new strips was very high. During a 6-weeks exposure of the strips in bee colonies, in group I with re-used strips 95.32% mites fell off on the. In group II with new strips, the fall of the parasite was only by 2.86% higher. The remaining part of the fall, amounting respectively to 4.68 and 1.82%, was collected from the bottom inserts following fumigation of bee colonies with Apiwarol. The evaluation of bromfenvinphos content in the strips following their withdrawal from bee colonies showed that the amount of active ingredient differed greatly and depended on their multiple use. For the strips used twice (group I), the content of active ingredient oscillated within the range 3.01 to 19.39 mg/strip, whereas for those used once (group II) it was within the range 26.65 to 51.18 mg/strip. Its level for the first strips was 8.22 mg, whereas in the second ones several times higher 38.78 mg per one strip. At the same time it should be stressed that only in re-used strips the bromfenviphos content was conditioned significantly (r = 0.551) by the degree of erasure of the microlayer covering them. The bromfenvinphos content found in the strips following a single 6-weeks exposure in bee colonies is sufficient for acquiring the high efficacy of treatment, which is demonstrated by the obtained results. Key words: bee colony, Varroa destructor, acaricide INTRODUCTION Preparations in the form of plastic strips covered with a contact action active ingredient against mites are convenient for varrosis control in bee colonies. Such a drug in Poland is Apifos. Its main characteristic is a very high varroacidal efficacy of 93.6 100% [Jeliński 1998, Jęruszuk, a, Konopacka et al. ]. According to Romaniuk and Witkiewicz [], treatment efficacy is influenced by the place where strips are hanged in the hive; it is not, however, conditioned by the chewing of the microlayer with active ingredient covering a strip by bees [Kazimierczak et al., Konopacka et al. ]. It results from the studies of Konopacka et al. [], evaluating the test formulas of Apifos, that even with a 3-times lower content of bromfenvinphos in relation to its level (50 60 mg) in strips of serialized, market-oriented production the treatment results are very similar, not differing significantly. Also Śledzinski et al.
50 B. Chuda-Mickiewicz i in. [1996], examining the usefulness of bromfenvinphos for varroosis control, obtained a very high efficacy, i.e. 100%, when using PE strips with 20 mg bromfenvinphos (with 40 60% concentration) in a microlayer. It results from the literature [Bratkowski and Wilde 1997] that antivarroosis preparations produced in the form of strips with synthetic pyrethroids Bayvarol (a.i. flumetrin) and Fluwarol (a.i. fluvalinate) can be used successfully for varroosis control in bee colonies for several years (3 to 5). The aim of the undertaken studies was to evaluate the efficacy of varroosis control with Apifos strips used in the previous season and to determine the bromfenvinphos content in the strips following a 6-weeks exposure in bee colonies in two and one apiary season. MATERIAL AND METHODS Experiment was carried out in the apiary of the Department of Apiculture, Agricultural University in Szczecin, in the early autumn and. Each year 16 bee colonies selected randomly, of similar vigour and settling the Wielkopolski hives, were included into the study. Out of them two groups were made, 8 bee colonies each. In, in a half of colonies of each group the mites infection was enlarged by supplying them with the brood or bees from a colony with clear clinic varroosis symptoms. Prior to the treatment, bee samples were collected in the amount of 250 worker bees, as well as the capped worker brood was sampled 3 cm 2, to determine a degree of Varroa destructor infestation. Next, within the colonies two Apifos strips were inserted, hanging them in the utmost beeways with brood. In group I (experimental) the strips were used in the previous season, thus the microlayer of these strips was erased in 50% in. In the colonies of group II (control) new strips were inserted produced, respectively, in and. The volume of mite fall was controlled by collecting dead forms of mites from the bottom inserts every 4th day. Following a 6-weeks Apifos exposure in colonies (recommended by the manufacturer), the efficacy of the treatment was evaluated by fumigating thrice the colonies with Apiwarol in 4-days intervals. In the second year of the study, the content of bromfenvinphos in the strips withdrawn from the colonies was determined in the Institute of Industrial Organic Chemistry. The obtained results were analysed statistically with MS Excel software. RESULTS The performed examination of bees and brood showed that bee colonies selected for the experiment in the two years were characterized by a relatively low initial invasion with Varroa destructor (Tab. 1). Prior to the treatment, the intensity of mite infestation in bees was 1.35% in group I and slightly lower, by 0.55%, in group II (control). Higher intensity in both groups was found in the brood, i.e. there were 3.06 mites per 100 cells on the in group I and 7.91 varroa forms in group II, with the infestation extensity (% cells infected with parasites) amounting, respectively, to 0.98 and 2.23%. Comparing the intensity of varroa infastation in bee colonies in the study years, a higher intensity was observed in the second year; this was due to their extra infestation with mites through supplying a part of bee colonies with the bees or brood strongly infected with the mite. Acta Sci. Pol.
The re-used Apifos strips... 51 Table 1. Evaluation of bee colony infestation with Varroa destruktor prior to treatment Tabela 1. Ocena poraŝenia rodzin Varroa destructor przed podjęciem leczenia Material tested Badany materiał Bees Pszczoły Brood Czerw Varroa invasion degree Stopień inwazji varroa intensity (%) intensywność (%) intensity (%) intensywność (%) extensity (%) ekstensywność (%) Year Rok Colony group Grupa rodzin I experimental I doświadczalna II control II kontrolna range zakres range zakres 0.0 1.77 0.56 0.0 1.08 0.46 0.0 15.76 2.44 0.0 4.41 1.30 1.35 0.80 0.0 5.30 0.0 25.64 0.0 1.32 0.0 10.25 1.38 0.0 22.90 4.44 4.62 0.0 42.40 12.23 3.06 7.91 0.41 0.0 5.42 1.09 1.51 0.0 11.46 4.62 0.98 2.23 In Table 2 is presented the volume of varroa fall due to the Apifos treatment and the Apiwarol fumigation. During a 6-weeks Apifos strips exposure in colonies in group I with re-used strips in, 92.08% mites on the fell off, while 96.30% mites in. In group II, with new Apifos strips, the parasite fall was slightly larger and amounted, respectively, to 97.53 and 98.37%. The efficacy of varroa control with the re-used strips (in group I) was thus lower by only 2.86% when compared to that obtained when using new Apifos strips, amounting to 98.18% (in group II). Observing the volume of varroa fall in the successive weeks of using both the re-used Apifos strips and the new ones, it was found that the prevailing majority of mites in both study years, over 80%, died during the first four weeks of their exposure in bee colonies (Fig. 1). Table 2. Varoacidal efficacy of Apifos Tabela 2. Skuteczność warroabójcza Apifosu Group Grupa I re-used strips I paski uŝywane II new strips II paski nowe Year Rok Apiwarol control fumigation Apifos Parasite fall-off Odymianie kontrolne Apiwarolem Total Osyp pasoŝyta range range Ogółem zakres zakres mites numer/bee colony 23 236 114.8 2 23 9.9 124.6 % 71.87 97.33 92.08 2.67 28.13 7.92 100.0 mites numer/bee colony 30 1773 410.2 1 48 15.8 426.1 % 78.18 99.67 96.30 0.33 21.82 3.70 100.0 mites numer/bee colony 262.50 12.87 275.37 % 95.32 a 4.68 100.0 mites numer/bee colony 93 313 168.0 0 10 4.2 172.2 % 91.0 100.0 97.53 0.0 9.00 2.47 100.0 mites numer/bee colony 73 1925 644.6 4 19 10.7 655.3 % 87.82 99.78 98.37 0.22 12.18 1.63 100.0 mites numer/bee colony 812.62 7.50 413.81 % 98.18 a 1.82 Medicina Veterinaria 2(1) 2003
52 B. Chuda-Mickiewicz i in. % 100 80 200 92.08 97.53 60 40 42.53 49.59 26.28 35.41 20 10.83 6.46 7.12 3.48 2.81 3.92 2.51 1.67 7.92 2.47 0 100 80 96.30 98.37 60 40 34.89 44.97 45.52 39.70 20 9.76 9.27 2.39 1.32 2.65 1.40 0.98 1.57 3.70 1.63 0 1 2 3 4 5 6 1 6 7 8 weeks tydz. Apifos Apiwarol group I experimental, re-used Apifos strips gr. I doświadczalna, paski Apifosu uŝywane powtórnie group II control, new Apifos strips gr. II kontrolna, nowe paski Apifosu Fig. 1. The efficacy of Varroa destructor control Rys. 1. Skuteczność zwalczania Varroa destructor The evaluation of bromfenvinphos content in the strips following their withdrawal from bee colonies in showed that the amount of active ingredient differed and depended on the multiplication of their re-use. (Tab. 3). In the strips used twice (group I), the content of active ingredient oscillated within the range 2.72 to 19.39 mg/strip, and in those used once 26.68 to 51.18% mg/strip. Its content in the former ones was 8.22 mg per one strip, while several times higher, 38.79 mg per one strip, in the latter ones. The content of bromfenvinphos in the strips used twice depended on the degree of erasure of the microlayer covering their surface (r = 0.551). This correlation was not stated (r = 0.107) in the strips used once for varroa control in bee colonies (Tab. 3). Acta Sci. Pol.
The re-used Apifos strips... 53 Table 3. Bromfenvinphos content in Apifos strips following repeated and non-repeated exposure in bee colonies Tabela 3. Zawartość bromfenwinfosu w paskach Apifosu po dwu- i jednokrotnej ekspozycji w rodzinach pszczelich Trait examined Badana cecha % strip surface microlayer erasure % wytarcia powierzchniowej mikrowarstwy paska Bromfenvinphos content (mg/strip) Zawartość bromfenwinfosu (mg/pasek) Correlation between examined traits WspółzaleŜność pomiędzy badanymi cechami * r. significant at p = 0.05 r. istotne przy p = 0.05 Group I re-used strips Grupa I paski uŝywane ponownie Group II new strips Grupa II paski nowe range od do 50 85 5 50 55.0 21.0 range od do 2.72 19.39 26.65 51.18 8.22 38.79 coefficient of correlation współczynnik korelacji 0.551* 0.107 DISCUSSION The efficacy of varroosis control demonstrated in the present study, 98%, for Apifos confirmed entirely the findings of Jeliński [1998], Jędruszak [] and Konopacka et al. [] that it is a preparation destroying the population of Varroa destructor in bee colonies in over 94%. A similar therapeutic effect (92% efficacy) was obtained by reapplying the same Apifos strips. Also Konopacka and Grula [] showed similar treatment efficacy (91.2%) with re-used Apifos strips. This means that the bromfenvinphos content determined of approximately 38 mg per strip with partlychewed by bees microlayer (with active ingredient) after a 6-weeks exposure, in colony, is sufficient to kill most mites when the strips are re-hanged in the hives. High effectiveness of Apifos strips, with a lowered content of bromfenvinphos compared to the new ones produced by Biowet, is confirmed by earlier studies by Śledziński et al. [1996], as well as by Konopacka et al. [], who tested experimental formulas of the evaluated drug. CONCLUSIONS When re-using the same Apifos strips for varroosis control in bee colonies a high, 92 96%, treatment efficacy is obtained. REFERENCES Bratkowski M, Wilde J., 1997. Akarycydy zagroŝenie jakości miodu (Acaricides a threat for the honey quality). Pszczelarstwo 48(3), 4 5. Jeliński K., 1998. Zwalczanie Varroa jacobsoni Oud. preparatem Apifos Biowet (Apifos Biowet in Varroa jacobsoni Oud. control). Pszczel. Zesz. Nauk., 42(1), 163 167. Jędruszuk A.,. Apifos nowy lek przeciw Varroa jacobsoni (Apifos a new drug against Varroa jacobsoni). Pszczelarstwo 51(8), 8 9. Medicina Veterinaria 2(1) 2003
54 B. Chuda-Mickiewicz i in. Jędruszuk A., a. Skuteczność warroabójcza preparatu Apifos (Biowet Puławy) na czerwiu oraz imago pszczoły miodnej. Pszczel. Zesz. Nauk., 44 (supl. do nr 1), 45 47. Kazimierczak J., Huras B., Bombińska D.,. Apifos zjawisko zgryzania mikrowarstwy towarzyszące stosowaniu preparatu warroabójczego. Pszczel. Zesz. Nauk., 44 (supl. do nr 1), 49 51. Konopacka Z., Bieńkowska M., Grula D.,. The efficacy of Apifos a new varroa killing formula. Pszczel. Zesz. Nauk., 44, 209 215. Konopacka Z., Grula D.,. Skuteczność warroabójcza kilku dostępnych w Polsce preparatów. 38 Naukowa Konferencja Pszczelarska Puławy 13 14 marca. Streszczenia materiałów s. 41 42. Romaniuk K., Witkiewicz W.,. Skuteczność preparatu Apifos do zwalczania inwazji Varroa jacobsoni u pszczół. Med. Wet., 56(10), 665 666. Śledziński B., Cieslak L., Konopacka Z., 1996. Bromfenvinphos in control of Varroa jacobsoni mite. Pszczel. Zesz. Nauk., 40(2), 179 182. ZWALCZANIE VARROA DESTRUCTOR PASKAMI APIFOSU UśYWANYMI POWTÓRNIE Streszczenie. Skuteczność zwalczania warrozy zarówno uŝywanymi w ubiegłym roku, jak i nowymi paskami Apifosu była bardzo wysoka. W czasie 6-tygodniowej ekspozycji pasków w rodzinach pszczelich, w grupie I, z powtórnie uŝywanymi paskami, osypało się 95.32% roztoczy. W grupie II, z nowymi paskami, osyp pasoŝyta był tylko o 2.86% większy. Pozostałą część osypu wynoszącą w grupach odpowiednio 4.68 i 1.82% zebrano z wkładek po odymieniu rodzin Apiwarolem. Ocena zawartości bromfenwinfosu w paskach po wycofaniu ich z rodzin wykazała, Ŝe ilość substancji aktywnej była bardzo zróŝnicowana i zaleŝała od krotności ich uŝycia. W paskach wykorzystanych po raz drugi (w I grupie) zawartość substancji aktywnej oscylowała w granicach od 3.01 do 19.39 mg/ pasek, natomiast po jednorazowym uŝyciu (w rodzinach grupy II) kształtowała się w granicach od 26.65 do 51.18 mg/pasek. Przeciętny jej poziom w pierwszych wynosił 8.22 mg, zaś w drugich był kilkakrotnie większy 38.78 mg w przeliczeniu na jeden pasek. NaleŜy przy tym podkreślić, Ŝe tylko w paskach uŝytych powtórnie zawartość bromfenwinfosu była istotnie (r = 0.551) uwarunkowana stopniem wytarcia pokrywającej jej mikrowarstwy. Stwierdzona zawartość bromfenwinfosu w paskach, po jednorazowej 6-tygodniowej ekspozycji w rodzinach, jest wystarczająca do uzyskania wysokiej efektywności zabiegu leczniczego, świadczą o tym uzyskane wyniki badań. Słowa kluczowe: rodzina pszczela, Varroa destructor, akarycyd BoŜena Chuda-Mickiewicz, Jarosław Prabucki, Grzegorz PeruŜyński, Jerzy Samborski Department of Apiculture, Agricultural University in Szczecin, Doktora Judyma St. 20, 71-466 Szczecin, Poland, e-mail: apis@biot.ar.szczecin.pl Jerzy Kazimierczak Institute of Industrial Organic Chemistry, Annapol 6, 03-236 Warszawa, Poland Acta Sci. Pol.