Varroa-infested honeybee colonies were exposed 5 times at 4 – day intervals to Chroococcus minutus (Kutz.), Calothrix parietina  (Nageli.)., Gloeocapsa giganteus  (Nageli.) and oxalic acid.
                During February 2006, treated colonies were closed for about ¼ hour, then fallen Varroa mites which received on Vaseline-smeared plastic board installed on the bottom board were counted at the end of each application. Also, the effect of such treatments on brood rearing activity and spring honey crop were studied. Results are summarized as follows:
1-                   The number of captured Varroa in the treated colonies decreased gradually until it recorded the lowest values after the 5^th application. On the contrary, the inverse was true in case of control colonies.
2-                   Percentages  of Varroa infestation decreased from 12.50, 13.50, 12.25 and 12.95% at the beginning of the experiment to 2.50, 2.13, 3.50 and 2.90% at the end of the treatment with Chroococcus minutus (Kutz.), Calothrix parietina  (Nageli.), Gloeocapsa giganteus (Nageli.) and oxalic acid. While it recorded 12.15 and 26.26% at the start and the end of the experiment in untreated colonies.
3-                   The total sealed brood areas increased significantly in treated colonies with Chroococcus minutus (Kutz.), Calothrix parietina (Nageli.), Gloeocapsa giganteus  (Nageli.) and oxalic acid,   recording 927.20, 726.50, 886.10 and 853.60 inch² / colony, respectively compared to 582.80 inch² / colony in control. The respective percentages of increase of sealed brood areas basing in control colonies as 100% were 159.09, 124.66, 152.04 and 146.47%.
4-                   Exposing bee colonies to the Chroococcus minutus (Kutz.), Calothrix parietina  (Nageli.)., Gloeocapsa giganteus  (Nageli.) and oxalic acid were giving significant increasing in  yield of citrus honey, recording 3.20, 2.21, 2.06 and 1.60 kg / colony respectively compared to 1.28 kg / control colony.