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The loss of bee colonies in recent years is a global phenomenon and Ethiopia is not exceptional. No single cause has been identified for the lose interactions of biotic and abiotic factors are speculated for the global bee colony decline. Following global warming and human population fast growth, natural forests which are used to be habitat and sources bee feed has been destroyed at fast rate. Also the contribution of bee pests and diseases is thought considerable for bee colony diminishing. Recently (2010), globally identify as causing bee colony dames bee mite varroa destructor has been reported in most beekeeping regions of Ethiopia. However, the effects of mite on bee colonies and their products, the mite strain type and its seasonal dynamics under local incident remain uncertain. Therefore, controlled experiment has been designed to unveil the basic questions with regards to the nature and the effects of the parasite under local conditions. Ten bee colonies were set up at Bako area which is 250 km west of Addis Ababa. Data collections were done for three years on monthly basis and collections of information were done on the parameters like the number of varroa mites on adults and brood bees and brood, pollen and nectar areas. Besides, morpho-size of the collected varroa mites were measured and compared with the morpho-sizes varroa mites collected from different localities. The study investigated negative correlation (P <-0. 0.513) between the number of mite and number of adult bees as well as brood, pollen and nectar areas. However, the number of mites on adult and brood bees as well as the mite's pessimistic effect varied between the colonies and the seasons. Based on morpho-size measurement, the mites were grouped into five mopho-clusters, but generally confirming all the strains belong to varroa destructor type. In spite of the presence of the parasitic varroa mite in all the bee colonies year round, all the colonies appeared to be healthy. The result from this study has enlightened local understanding on the seasonal dynamics, effects and species of varroa mite. However, further study that entails investigations on biological/ behavior of both the parasite and the host is suggested to avail better understanding on how local bees were not affected following the number of parasailing varroa mite.

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Abstract:The recent decline of honey bee population raises speculations from different angles. Exposure to poisoning substances is proposed as prime factor for honeybee deaths and colony reduction. Euphorbia contifolia, commonly known as "key abeba" is suspected as poisonousplant to honeybees and other animals in different regions of Ethiopia. An attempt was made to test the phytotoxic effect of this plant on honeybees in Illubabora and Jimma zones of Oromia region. Questioner survey and controlled experiment were used to assess the effect of E.contifolia on honeybees during its flowering season. Data on numberof dead adult bees and bee broods were counted at every 3hr, 4hr, 5hr, 6hr and 12hr of the day for five consecutive days. The survey result indicates that anaverage of 52% of the respondents of the two zones suspected that E. contifolia causes death and narcosis of foraging bees. In contrast, the mean mortality rate of adult and brood bees between the treatment and control group did not significantly differ (P >0.05), and no any narcosis symptom observed during the experimental test. This demonstratesthe absence of distinct toxic effect of the plant on honeybees. However, further study on the plant's nectar and pollen active compound is recommended to reach into full understanding.