Tracking Existing Factors Directly Affecting the Reproduction of Bumblebees: Current Knowledge.

Simple Summary: Bumblebees are important pollinators of both natural and agricultural ecosystems. The quality of their colonies is highly dependent on the reproductive success of the queens and males. This process can be influenced by numerous factors, both positive and negative, some of which directly affect reproductive processes. In this paper, we review current studies on environmental and biological factors that directly affect bumblebee reproduction, including floral resources, pathogens, pesticides, worker behavior, species competition, and hormonal and genetic influences. More studies, particularly those focusing on bumblebees themselves, are needed to understand the effects of these factors and other potential elements. This understanding is essential in order to meet the demands of agricultural pollination and address the decline in wild bee pollinators worldwide. Bumblebees are primary social insects and a vital class of pollinating insects. Their distinctive reproductive mode is characterized by the independent initiation and construction of the nest by the queen and the subsequent production of sufficient workers, males, and gynes following colony development. After successful mating, the queen transitions to the first phase of its annual life cycle. The reproductive processes are directly influenced by environmental factors, including floral resources and pesticides. Moreover, the reproductive level is regulated by biological factors, particularly the role of workers, who participate in egg laying and pass on their genetic material to the next generation of queens. Successful reproduction can only be achieved by maintaining colony development under natural or artificial breeding conditions. Consequently, understanding the known factors that influence bumblebee reproduction is essential for developing conservation strategies for wild bumblebees and for successfully breeding diverse bumblebee species. Breeding various bumblebee species is crucial for in-depth research into known factors and for further exploration of other potential factors, which will also help to meet the demand for pollination in agricultural facilities globally. [ABSTRACT FROM AUTHOR]