الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
This study was conducted in an apiary at Dakahlia governorate ( Meet Salseel village), and Beekeeping research department, Plant Protection Research Institute during the period of 2007/2008.The aim of this work is to study the following points of about fluctuation of population dynamics of varroatosis on Apis mellifera Carnica. 1. Seasonal fluctuation of population dynamics of varroatosis: The drone brood were absent during November, December and January in both two years of the study. High infestation during December on sealed workers brood 55.15 %, and 45.08 % while it was 80.10 %, 70.41 % in sealed drone brood during September and October. Highly significant different was observed between worker and drone infestation during the second year of the study. Infestation by varroa mites on adult and sealed workers brood: The infestation was gradually increased from January till October. The infestation recorded 4.18 %and 62.12% on adult workers and 3.11% and 55.15% on sealed worker brood on 2007 and from 3.16% to 65.17% and 1.55% to 45.08% on adult and sealed brood of worker during 2008. 2. High infestation were detected in the drone brood 80.10%,70.41% during September 2007 and October 2008, then it decreased gradually recording 8.25%, 3.0% in sealed drone brood during February of 2007 and 2008 respectively. 3. The ectoparasite varroa mite load was relatively low in worker brood cells compared to drone brood. Generally the sealed drone brood cells showed the highest average infestation 38.10% and 26.79% while it was 20.10% and 15.64% during 2007 and 2008 respectively. 4. Average reduction due varroa infestation recorded. Reduction % in sealed brood and the estimation date. The highest reduction was recorded at 55.15% on December for the sealed workers brood area and at 80.10% on September for sealed drones brood area. 5. Body weight of newly emerged workers and drones was affected under varroa infestation at 2-3, 3-5 and >5 mites. The reduction recorded 3.63% to 45.35% in workers and from 0.89% to 34.92% in drones when infested by 1 to >5 varroa mites. Significant negative correlation coefficient value was found between varroatosis infestation and body weights of pure honey bee workers and drones. 6. The high infestation level of varroa mite caused significant decrease in length and width of these organs of newly of proboscis, forewing, hind basitarsus, Targite ΙV, and wax mirror. 7. Results showed that after two and three weeks of worker emergency the reduction in lobe diameter of hypopharyngeal glands positively correlated with level of infestation by varroatosis. The percentage reduction of gland development averaged 10.4%,15.0% and 16.7% when bees were infested by 2-3, 4-5, and >5 per cell after one week from emergency, respectively. This value significantly increased to 27.0%,29.0% and 39.1% after 3 weeks of emergence. 8. The effect of varroa infestation proved to be destructive to honey yield. In the first year (2007) one healthy colony in clover season produced 8.0kg , and 5.0 kg in cotton season while infested colony produced 3.0 and 1.50 kg in the same seasons. In the second season the colony produced 8.0 kg and 6.0 kg at the two seams while uninfested ones was 62% and 68.75% and that of cotton season 70.0% and 66.7% respectively. This reduction may be attributed to weakness of colonies and individuals. The control of varroa mite infestation by using natural substances is more recommended than the use of other chemical materials in order to avoid harmful effect to honey bees as well as beekeepers themselves.