2 Apiculture Research Division by s0o53A0V

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									    Biometrical study on the effect of varroa mite, Varroa jacobsoni infestation on
           honeybee workers with special reference to honey production

     Sharaf El-Din H.A.1, S.M.Abo-Taka1, A. El-Nabawi1, M.A. El-Samni1 and
                                R.E.S.Ibrahim2
1
  Economic Ent. and Agricultural Zoology Department, Faculty of agriculture ,
  Menoufia, University, Egypt.
2
  Apiculture Research Division, Agric. Res. Center, Giza, Egypt.

                                   ABSTRACT

       The present work was aimed to add a new contribution to our
available knowledge on the effect of external parasitic mite, Varroa
jacobsoni on some biometrical measurements in honeybee, Apis mellifera
workers and honey production. To determine the relation between
infestation by varroa and honey yield. All samples of workers and honey
yield were collected from uninfested and infested F1 Carniolan colonies at
Menoufia Governorate during citrus and clover seasons for two
successive years. The results showed that the measurements of forewing
(length and width) hind wing (Length and width) and proboscis (Length)
for honeybee workers were affected by the infestation of varroa mite.
There were significant differences between all measurements for infested
and uninfested workers. The results also showed that the average weights
of honey yield collecting from citrus and clover seasons during two
successive years were affected by infestation of varroa mite. There were
significant differences between honey yield from infested and uninfested
honeybee colonies. There was negative correlation between infestation by
varroa and honey yield in addition between varroa infestation and
biometrical measurements of both fore& hind wings and proboscis.

Key Words: Biometrical, honeybee, varroa mite, carniolan, citrus, clover.

                         INTRODUCTION
       The honeybee, Apis mellifera, is considered one of the most
important beneficial insect for the man. Honeybee colonies gave us
nutritional, medical and industrial products (Honey, bees wax, royal jelly,
pollen, propolis, bee venom as well as brood).
       When honey bees gather nectar and pollen, pollinate hundreds of
different kinds of commercial crop plants. Estimation of benefits and




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increasing of quality and quantity of bee pollinated crops is about 20
times values more than all hive products together.
     The infestation by Varroa jacobsoni in honeybee colonies was
recorded for the first time in Egypt in 1987 (Wienands and Madel, 1988)
and within the last 15 years, the parasite has become a subject of bee-
keepers concern, and has been found in the majority of the Egyptian
apiaries (Abd El-Fattah et al. 1991).
     The impact of varroa infestation depends on the degree of infestation
in the honeybee colony: low infestation apparently causes little damage,
while high one leads to colony death (Cavalloro, 1998).
                 MATERIALS AND METHODS
       This work was carried out in the apiary and laboratory of
Economic Entomology and Agricultural Zoology Department, Faculty of
Agriculture, Menoufia University, Shebin El-Kom Egypt, and two
apiaries at Berket El-Saba center and Quessna center in Menoufia
Governorate, Egypt during two successive seasons. To study the effect of
varroa mite infestation on some biometrical measurements in honeybee
workers and honey production.
Honeybee strain:
       F1 Carniolan honeybee colonies in modern woody (Langstrougth)
hives which are wide used in Egyptian apiaries.


Biometrical measurements:
     Micro measurements for infested and uninfested workers were done
by measuring forewing, hindwing and proboscis using stereomicroscope
with the aid of micrometer eye piece (lens). Fifteen measurements were
done for each organ. All samples were collected from uninfested and
infested colonies at Berket El-Saba locality where it were mounted on
glass slides. Measurements were done for two successive years.


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     Newly emerged workers (0 – 24 hrs age), were collected from sealed
brood combs screened at wire cages and placed in incubator temperature
of 30  1C. and relative humidity 60%. 45 workers in 3 replicates each
of 15 workers were used in for measurements of:

     1- Right fore-wing length and width.
     2- Right hind-wing length and width.
     3- Proboscis length.
     Measurements were done in mm, using a stereoscope binocular
microscope with an ocular micrometer.

Honey production:
   To study the effect of varroa infestation on the honey yield, three
apiaries were chosen at each of Berket El-Saba, Quessna and Shebin El-
Kom, the first was free of varroa infestation and the second was naturally
infested with varroa mite. The weight of honey was calculated for each
uninfested and infested colonies two times every year (citrus and clover
seasons). This point was done for two successive years.


Statistical analysis:
     All obtained data were statistically analyzed according to ANOVA
test Snedecor and Cochran (1973) and Costat 22 (1998).


                    RESULTS AND DISCUSSION
     The work was carried out to study the effect of varroa mite
infestation on some biometrical measurements of honeybee workers and
honey production.

I. Effect on some biometrical measurements:

     Data presented in Table (1) included the measurements of forewing
(length and width), hindwing (length and width) and proboscis of workers



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              infested with varroa mite compared with uninfested ones for two
              successive years.

              Table (1): Effect of varroa infestation on measurements (mm) of
                        honeybee worker at Berket El-Saba locality along two
                        successive years.
                                               Measurements / worker (mm) (mean 15 worker)
  Status of bee
                                                   Forewing                 Hindwing             Proboscis
    colonies                                                                                      length
                                             Length        Width      Length        Width
                               Range       9.24– 9.30   2.7 – 3.6  6.2 – 7.0     1.7 – 2.1       5.87 – 6.0
                 Uninfested    XS.E       9.270.01    3.160.06   6.720.06    1.880.03       5.920.01
                               C.V         0.21         7.21        3.72         7.44            0.61
First year




                               Range       8.9 – 9.3    2.6 – 3.3   6.1 – 6.8    1.5 – 1.8       5.58 – 5.64
                               XS.E       9.070.04    2.840.07   6.560.06    1.70.15        5.610.05
                 Infested      C.V         1.65         6.33        3.65         6.23            0.37
                               R%          2.15         10.12       2.38         9.57            5.23
                               t. cal.     5.12         4.26        1.79         1.28            31
                               Range       9.25– 9.30   2.8 – 3.4   6.1 – 7.0    1.6 – 2.0       5.88 – 5.98
                 Uninfested    XS.E       9.280.01    3.140.06   6.760.06    1.860.03       5.930.01
                               C.V         0.18         4.77        3.69         6.98            0.5
Second year




                               Range       8.9 – 9.2    2.5 – 3.3   6.1 – 6.8    1.6 – 1.9       5.58 – 5.63
                               XS.E       9.10.02     2.960.05   6.590.04    1.740.02       5.610.01
                 infested      C.V         1.19         7.77        2.88         5.86            0.26
                               R%          1.93         5.73        2.51         6.45            5.39
                               t. cal.     6.66         2.56        3.25         2.00            40


              t. tab 0.05 = 2.018        t .tab = 2.467    R% =Reduction %
              X = Mean                   S.E = Standard errors     C.V = Coefficient Variation
                    Data presented in Table (1) indicated that the measurements of
              honeybee workers (forewing, hindwing and proboscis) at Berket El-Saba
              locality for two successive years were affected by the infestation of
              varroa mites.

                    1- Forewing

                      1.1- Forewing length:

                    Results in Table (1) indicated that the mean length of forewing in
              uninfested workers were 9.27 and 9.28 mm for the first and second


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season, while it was 9.07 and 9.10 mm for infested workers at the 1st and
2nd years.

     The reduction percentage in forewing length was 2.15% and 1.93%
for the two years.

      1.2- Forewing width:

     The mean widths of forewing in uninfested workers were 3.16 and
3.14 mm for the first and second season, while it was 2.84 and 2.96 mm
for infested workers at first and second season.

     The reduction percentage in forewing width was 10.12% and 5.73%
for the two years.

     2: Hindwing:

      2.1- Hindwing length:

     Regarding to the measurements of hindwing Table (1), the mean
length of hindwing in uninfested workers were 6.72 and 6.76 mm for the
first and second years, while it was 6.56 and 6.59 mm for infested
workers at first and second years. The reduction percentage in hindwing
length was 2.38% and 2.51% for two years.

      2.2- Hindwing width:

     The mean width of hindwing in uninfested workers were 1.88 and
1.86 mm for first and second years, while it was 1.70 and 1.74 mm for
infested workers at first and second season. The reduction percentage in
hindwing width was 9.57% and 6.45% for the two years.

     3- Proboscis length:

     Results of the experiments, Table (1) cleared that the mean length of
the proboscis in uninfested workers were 5.92 and 5.93 mm for the first
and second years, while it was 5.61 mm for both of two years under



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investigation for infested workers. The reduction percentage in proboscis
was 5.23% and 5.39% for the two years.

     Results are in harmony with those obtained by Serag El-Din (1999)
who found that the forewing length and width were significantly reduced
due to Varroatosis and he found that the length in uninfested workers was
9.28m, while it was 9.10 mm for infested workers, he found that the
width was reduced from3.23 mm in uninfested workers to 3.00 mm for
infested workers, and stated that the mite infestation exhibited similar
effects on the hind wing. Moreover the length of proboscis was 5.98 mm
in workers from uninfested colonies, and was 5.65 mm in workers from
infested colonies. Also, obtained results were in harmony with Bedair
(1996) who found that parasitic mites of 5 – 7 per cell reduced forewing
length and width to 7.09 and 5.88 mm comparing with uninfested worker
bees.

II. Effect on honey production:

     The average weights of honeybee yield from honeybee colonies at
three localities in Menoufia governorate (Berket El-Saba, Quessna and
Shebin El-Kom) are recorded in Table (2) for the first and second years
during citrus and clover seasons.
     1- At Berket El-Saba:
     The average weight of honey yield (kg) /colony, which collected
from citrus or clover season as well as the reduction percentage in honey
yield, were recorded at Table (2). In the two years, extracted honey in
citrus season weighed (2.72 and 2.60 (kg)/colony) for uninfested colony
compared to (2.62 and 2.48 (kg)/colony) for infested colony during the
first and second years.




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Table (2): Influence of varroa infestation on honey yield collecting of
       citrus and clover at three localities for two successive years.

                                Ave. weight of honey yield (kg) / colony
                                        Citrus               Clover
      Status of bee colonies
                                First       Second      First     Second
                                year         year       year       year

                               Berket El-Saba


    Uninfested                  2.72             2.60    4.14         3.84

    Infested                    1.20             1.16    2.62         2.48

    Reduction %                55.88         55.38      36.71      35.41

                                  Quessna

    Uninfested                  2.78             2.64    4.20         3.92

    Infested                    1.26             1.22    2.68         2.52

    Reduction %                54.67         53.78      36.19      35.71

                               Shebin El-Kom

    Uninfested                  2.88             2.74    4.24         3.98

    Infested                    1.40             1.30    2.72         2.58

    Reduction %                51.38         52.55      35.84      35.17



     The highest reduction in honey yield were (55.88 and 55.38%)
recorded at for the first and second years during citrus season, while the
lowest reduction was (36.71 and 35.41%) for the first and second years
during clover seasons.
     The average weight of honey yield in clover seasons were (4.14 and
3.84 kg) for uninfested colony compared to (2.62 and 2.48 kg) in infested
colony during the first and second years.


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     2- At Quessna:
     The average weight of honey yield from honeybee colony per kg.
which is collected from citrus and clover seasons as well as the reduction
percentage in honey yield were recorded at Table (2).
     The average weight of honey yield in the two citrus seasons the first
and second years were (2.750 and 2.640 (kg)/colony) for uninfested
honeybee colony compared with (1.260 and 1.220 (kg) /colony) in
infested one.
     Results of the experiments during the two clover seasons showed
that the average of honey yield were (4.20 and 3.92 (kg)/colony) for
uninfested colony compared to (2.68 and 2.52 (kg)/colony) in infested
colony.
     The highest reduction were (54.67 and 53.78%) recorded during
citrus seasons, while the lowest reduction was (36.19 and 35.71%)
recorded during clover seasons.
     3- At Shebin El-Kom:
     The average weight of honey yield (kg)/colony, collected from citrus
and clover season as well as the reduction percentage in honey yield were
recorded at Table (2).
     In the first and second years extracted honey in citrus season
weighed (2.88 and 2.74 (kg)/colony) for uninfested colony compared with
(1.40 and 1.30 (kg)/colony) in infested colony.
     The average weight of honey yield in clover season were (4.24 and
3.98 (kg)/colony) for uninfested colony compared to (2.70 and 2.58
(kg)/colony) infested colony during the first and second years.
     The highest reduction in honey yield were (51.38 and 52.55%)
recorded at the first and second years, during citrus seasons. While the




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lowest reduction was (35.84 and 35.17%) recorded at the first and second
years during clover season.
     The results in Table (2) showed no remarkable variation was
recorded among the three localities for both citrus or/and clover honey
yield along the two years under investigation. The reduction percentages
in honey yield were ranged between 51.38 and 55.88% for citrus and
35.17 and 36.71% for clover along the two years.
     Similar results were obtained by Serag El-Din (1999) reporting that
extracted honey in citrus season weighed (4.00 kg) for uninfested colony
compared to (1.5 kg) in uninfested one (62.50% reduction). Also, during
clover and cotton seasons, he stated that similar reductions in honey yield
due to Varroa jacobsoni infestation were recorded; (60.78 and 62.50%),
respectively, with average reduction in honey yield (61.93%).
     Our results were in harmony with Fath-Allah (2004) who found that
the average of honey production in Assuit region during clover honey
season 2002 and 2003 were 3.95 (kg)/colony and 5.18 (kg)/colony for
Carniolan race and Carniolan hybrid.




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                             REFERENCES
Abd El-Fattah, M.A.; E.M. Nour and M.A. El-Shemy (1991). Efficacy of
      some chemical compounds to control Varroa mite (Varroa jacobsoni
      Oud) in honeybee colonies in Egypt. Egypt. J. Appl. Sci., 6(12):
      139-152.
Bedair, E.I.H. (1996): Studies ion certain honeybee acarine diseases and its
       control. Ph.D. Thesis, Fac. Agric., Al-Azhar University., pp: 168.


Cavalloro, R. (1998). European research on varroatosis control. A.A.
       ballkema / Rotter-dam /Book-field, 259 pp.
Costat 22 (1998): A computer program for statistical analysis.
Fath-Allah M. (2004): Comparative studies between the characters of some
      races and hybrids of honeybee in Assiut region, Upper Egypt. Ph.D
      Thesis, Fac. Agric., Assiut Univ., 200 pp.
Snedecor, G.W. and G. Cochran (1973): Statistical methods. 6th ed.; Iowa
      State Univ. Press Iowa, USA, 560 pp.
Serag El-Din, F. S. (1999). Studies on the varroatosis (Varroa
      jacobsoni). Ph.D. Thesis, Fac. of Agric. Kafar El-Sheikh,Tanta
      Univ, , Egypt, pp. 127.
Wienands, A. and G. Madel, (1988): Haemocytes of honeybee, Apis
      mellifera, and their changes during Varroa disease. Entomologia
      Generalis, 14(2): 81-92 .




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 ‫دراسة بيومترية على تأثير االصابة باكاروس الفاروا ‪ Varroa jacobsoni‬على شغاالت نحل‬

                                  ‫العسل مع االشارة النتاج العسل‬

  ‫1‬
      ‫حسنى عبد الجواد شرف الدين1 ، صفاء مصطفى ابو طاقة1 ، احمد النبوى1 ، محمود على السمنى‬
                                     ‫2‬
                                         ‫رضا عليوة سند ابراهيم‬
       ‫قسم الحشرات االقتصادية والحيوان الزراعى كلية الزراعة= جامعة المنوفية- شبين الكوم- مصر.‬   ‫1‬


                                    ‫قسم بحوث النحل مركز البحوث الزراعية- الدقى- جيزة -مصر.‬      ‫2‬




                                         ‫الملخص العربى‬
‫تهدف الدراسة الى القاء الضوء حول مزيد من المعلومات عن تاثير طفيل الفاروا كطفيل خارجى‬
‫التطفل على بعض الصفات البيومترية لشغاالت نحل العسل وانتاج الطوائف للعسل، وذلك لتحديكد‬
‫العالقة بين االصابة بالفاروا وانتاج العسل . تم اخذ جميع العينات من الشغاالت واالعسال من خاليا‬
 ‫هجين اول كرنيولى سواء كانت مصابة اوغير مصابة من محافظة المنوفية خالل موسكمى المكوال‬
‫والبرسيم لعاميين متتاليين . واوضحت النتائج ان كل من طول وعرض الجناح االمكامى والخلفكى‬
‫وطول الخرطوم تاثرت باالصابة بالفاروا ، وان هنا فروق معنوية بين القياسات فى حالة االصكابة‬
 ‫او عديمة االصابة . ايضا متوسط وزن محصول العسل المنتج خالل موسمى الدراسة سواء للمكوال‬
‫او البرسيم قد تاثر باالصابة بالفاروا حيث كانت هنا فروق معنوية بين انتاج العسل فى الطوائكف‬
‫المصابة وغير المصابة . وان هنا عالقة سلبية بين انتاج العسل وتاثير االصابة بالفاروا وايضا كان‬
‫هنا عالقة سلبية بين القياسات البيومترية سواء الجناح االمامى او الجناح الخلفى او طول الخرطوم‬
                                                                      ‫ودرجة االصابة بالفاروا.‬




                                                 ‫11‬

								
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