A review of the factors related to honey bee colony losses

Over the past ten years, some regions of the world have faced a significant decline in honey bee colonies. In fact, honey bee losses are not an unusual phenomenon, but recently, in many countries of the world, a significant decrease in bee colonies has been observed. Cases of this type of death in the United States of America, many European countries and the Middle East have attracted a lot of attention, mostly due to the lack of an identifiable cause. Due to the diverse social behavior of honey bees, it is difficult to determine the main factors in causing colony losses. In addition, honey bees are in contact with many environmental factors in their daily activities and they are exposed to a multitude of human activities and their consequences. However, various factors have been considered in bee losses and recent research has identified some of the most important of them, which include pests and diseases, bee management, beekeeping practices and bee breeding, climate change, agricultural activities, and pesticide use. Global studies have reported Varroa as the main factor in honey bee colony losses, followed by Nozma ceranae. It is clear that many factors influence honey bee colony losses worldwide. Increased monitoring and scientific research should shed new light on the factors involved in recent bee colony losses. The present review focuses on the main factors that influence the increase in bee colony losses.