Studies were accomplished to identify the important factors affecting successful virgin queens production in Sohag during 2007 and 2008 years. In order to find out the best teaching for rearing virgin queens by grafting method. Markedly differences in the mean number of virgin queens between single and double grafting methods, specially in spring and autumn seasons; in spring mean number of accepted cells of 43.77 with 37.66 emerged queens and 49.85 with 47.07 emerged queens were obtained when single and double grafting were used methods respectively. Spring season was favorable for queens rearing, followed by autumn and summer, while winter season came the latest. There was a clear relationship between larval age at grafting and the larval acceptance, one day old worker larvae gave the highest number of virgin queens emerged. On the other hand, the queen must be removed outside the hive 48 hrs before starting larval grafting to obtain the highest numbers of accepted queen cells. In general, double grafting, situating the cell cups frame in the hive center of the hive and fitting the cell cups on the top and bottom bar, gave the best method for queens acceptance and queens production. However, cell cups fitted on the edges of the bars were successfully reared when ambient temperatures were high in spring season, but queen cells in the center of the hive's brood nest were correlated with higher temperature and had a greater chance for emergence.

Experiments were carried out on honey bee colonies (Apis mellifera) during the winter of 2008 and spring of 2009 using colonies wintered with five levels of varroa infestation (0.0, 3.8, 9.0, 13.1 and 22.9%) in the Central Region of the kingdom of Saudi Arabia. The goal of the present work is to determine varroa treatment thresholds and colony collapse level. Response variables examined included varroa mite infestation level (%), cm2 of brood number of frames of brood, number of frames covered with adult honey bees and mites recovered on sticky boards. The data obtained reveled that no significant differences were noticed in cm2 of brood, number of frames of brood, and number of frames of bees in colonies (range of 0.0 to 9.0% varroa infestation or 0.0 – 0.9 mites/bee). Colonies with 13.1% infestation (0.13 mites/bee) exhibited a significant reduction in all measures of performance. The present results suggested that honey bee colonies can tolerate a level of 9.0% varroa infestation (0.9 mites/bee) during the winter without evidence of colony injury. It also suggested that 13.1% infestation (0.13 mites/bee) is the colony collapse or economic injury threshold in the Central Region of the Kingdom of Saudi Arabia. Also colonies with 12.3 or more mites falling on sticky boards after 48-hour period were likely to have lower populations of bees and brood the following spring.