الفهرس 
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Abstract
The Varroa mite Varroa destructor is very invasion to honey bee, Apis mellifera, colonies that are not genetically resistant. In recent years mite resistance to chemical acaricides has become a problem throughout the world. Therefore, rotating chemicals, delaying treatment and using natural controls are recommended to manage mites in a more sustainable manner.
The parasitic mite caused serious problems for world beekeeping. It has been introduced worldwide and considered as one of the most dangerous pests of honey bees.
As a consequence of the importance of the ecological factors, temperature and the relative humidity have received the maximum interest in our study of Beni-Sweif Governorate and
aimed to investigate:
1. Population dynamics and seasonal fluctuations of Varroa destructor on honey bees in three regions of Beni-Sweif City, Ihnasia El-Madina and Sods Al Omarraa at Beni-Sweif Governorate from 22/12/2003
to 22/2/2004.
II. Evaluation the efficiency of some essential oils and chemical compounds as Varroa controls.
a. Essential oils treatments and doses
Three of the crude volatile oils obtained from El-Gomhoria, Co. for Drug and Chemical Egypt, were used for this
experiment: •Eucalyptus oil (Eucalyptus golobulus labillardiere).
•Thymol oil (Thymus vulgaris L.).
•Peppermint oil (Mentha sp.).
The volatile oil treatments were applied via three main application methods:
•Feeding • Evaporation • Spraying b. Chemical compounds
Four chemical compounds were chosen to test their efficacy and compare with essential oils in the combat of Varroa destructor mite
1-Formic acid (85% conc.).
2-Oxalic acid dehydrate (Oxalic acid 99.5%).
3-Apistan (fluvalinate 10%).
4-Bayvarol (0.9 flumethrine active ingredient). Experimental period
This experiment was carried out at 17 of August to 15 of September; 15 of October to 15 of November; 15 of December to 13 of January; 15 of February to 15 of March and 15 of April to 15 of May for the seasons 2004 _ 2005 and 2005_ 2006.
The data collected revealed the following results: Varroa
A- Population dynamics and seasonal fluctuations of Varroa mite
The experiment was carried out, starting from 22/12/2003 to 22/12/2004. Ninety naturally infested colonies, similar in their strength were used. The regression between the environmental conditions (temperature and relative humidity) is more favorable for Varroa levels infestation particullary in Beni swief studies locations.
?fil. Varroa infestation (%) in sealed worker brood:
The highest infestation rate was recorded at winter and autumn seasons were (17.2%, 16.00) & (17.13%. 14.72%) and (15.83%, 13.10%) at Beni-Sweif city, Ihnasia and sids, respectively. While the lowest rate was recorded at summer and spring seasons were (3.10 & 8.86%), (2.52 & 8.19%) and (2.52 & 7.57%) for each.
?i+. Varroa infestation (%) in sealed drone brood:
Varroa infestation level in sealed drone brood showed increase at season activity related to brood drone increase, the Varroa infestation (%) at late winter and spring were 26.56%, 12.86% & 22.00% , 4.71% and 19.89%, 10.19%, while with the brood drone recorded 10.17, 14.71 & 9.00, 13.43 and 15.00, 15.14 inch2/colony for each tested at Beni- Sweif city , Ihnasia and sids, respectively.
Varroa infestation (%) in adult workers:
Varroa infestation level in adult workers recorded the highest rate at late autumn and winter beginning. They were 27.67%, 25.33%. 21.33% for Beni-Sweif city, Ihnasia and sids, respectively. While the lowest rates was recorded at summer season 0.67% & 0.33%.
?5A, Fallen dead Varroa mite :
Counted fallen dead Varroa mites on the bottom hives at winter and autumn were; (34.21 & 34.95), (24.17 & 20.43) and (28.83 & 29.67) mites/colony for Beni-Sweif city, Ihnasia and
sids, respectively. While the lowest values were recorded at summer and spring seasons.
Natural Varroa infestation levels:
The natural Varroa infestation level affected by many environmental factors, among these factors is variability of temperature and relative humidity.
B- Evaluation the efficiency of some essential oils and chemical compounds for Varroa controls
Essential oils:
Feeding method:
* Varroa reduction (%) in sealed worker brood and adults:
1-Using the essential oils against Varroa mite resulted in high reduction in the Varroa population dynamics with all tested oils using different application methods particularly with the thymol followed with eucalyptus and peppermint oils.
2-The best period for reduction Varroa infestation through using different essential oils was October-November of the year.
3-The Varroa reduction was 80.23% at Feb-March 2005 and 77.75% at Feb-March 2006 with treatment by thymol oil in worker brood, while the lowest values 40.62% & 46.24% were recorded at April — May of the year 2005 & 2006.
* Fallen dead Varroa mite :
1- The results obtained from application of the experimental oils revealed presence significant differences among the
numbers of dead Varroa mite dropped in different seasons of the year. During late winter and early spring seasons, the fallen dead Varroa mite reached to 284.99 & 300.00 mites /colony with the thymol oil at 2005& 2006 years , respectively.
2-Honeybee colonies fed with the essential oils added to the sugar solution indicated significant high mortality of the parasite mite than those colonies fed with pollen substitute only.
3-Mixture of certain tested essential oils provided to the experimental colonies through having feeding syrup a great effect on the Varroa population particularly with concentrations for eucalyptus, thymol and peppermint as ratio of 1:2:1, respectively.
?f*,. Evaporation method:
• Varroa reduction (%) in sealed worker brood and adults
1-Evaporation of the thymol, eucalyptus and peppermint oils at different concentrations was markedly resulted in highly significant of Varroa reduction compared to control one.
2-The 2❑d and 3rd concentrations of the thymol oil (10% & 20%) caused high Varroa reduction of most periods of the year, followed with eucalyptus and peppermint oils.
* Fallen dead Varroa mite:
1- Varroa population and mortality rate on adhesive board of the colonies treated with the essential oil was statistically highly significant compared to control one.
They were 503.01 & 577.00 mites/colony with the optimal selected concentrations of the thymol (10% & 20%), respectively.
2-The number of Varroa mites knock down on the board sheet, 3 days earlier with the thymol oil, followed with the eucalyptus one.
3-It is preferable to use thymol oil for controlling the Varroa mite.
2s. Spraying method:
•Varroa reduction (%) in sealed worker brood and adults
4-The thymol oil recorded the highest Varroa reduction population reached to 93% during the experimental years 2004 &. 2005 followed by peppermint and eucalyptus which resulted in 88.12 % & 85.75%, respectively.
5-The 3rd concentration (1%) of the thymol and peppermint oils caused the highest significant mite reduction.
•Fallen dead Varroa mite:
1-Non-significant differences among the number of fallen dead Varroa with treatment with essential oil concentrations .
2-The high fallen dead Varroa mite rate (43.00-98.67 mite/colony) was after the 3rd day of the first treatment with all oil concentration used.
3-Spraying method was applied in the late spring and early autumn, because the temperature its suitable, but it is difficult application.
Chemical compounds:
* Varro reduction (%) in sealed worker brood and adults
1-The therapeutic efficacy of the tested chemical compounds towards Varroa mite could be arranged in the following descending order; Apistan > Bayvarol > formic acid > oxalic acid.
2-The Apistan, Bayvarol, formic acid and oxalic acid caused high reduction percentages of the Varroa population in worker brood. They recorded
95.34%, 93.05%, 89.96% & 75.48%, respectively.
Fallen dead Varroa mite:
The rate of the fallen dead Varroa mite was very early detected after chemotherapy by chemical acaricides and this was evident at the 1St24 hrs. It ranged from 87.33 to101.33
mite/colony.
Productivity of the honeybee colonies:
The reflection effects of tested the essential oils and chemical compound used to controlling Varroa mite positive affected on the honeybee productivity, during tested two seasons (2004 -2006)