Depending on the species, bumblebees are different in appearance, but also size. For example, Bombus genus contains more than 250 species of bumblebees. Bumblebees are yellow-black, sometimes with reddish last part of the body. Color and their size often cause fear and panic but bumblebees are in nature very gentle and non-aggressive pollinators.
They are peaceful insects and will only attack when they feel backed into or when their hive is disturbed. When a bee stings, it injects venom into its victim. Only female bumblebees (queens and workers) have a sting, male bees (drones) do not. Unlike a bee sting, the sting of a bumblebee has no hooks, which means that a bumblebee can withdraw its sting without separation from his stomach and a bumblebee can sting several times.
Bumblebees, like bees, are important pollinators for agriculture. Population decline that affected pollinators in Europe, North America and Asia is in scientific circles a matter of concern. Bumblebee population decline is mainly caused by loss of habitat as well as higher and higher use of pesticides.
Bumblebees as such do not have active defense and do not attack and sting near the hive witch has been successfully used for pollinating in greenhouses. They are successfully used in winter or early spring period when their dwellings possibly stay on the sunny part of the greenhouse to encourage you to an earlier development.
They are successfully used to pollinate greenhouse crops like tomatoes, strawberries, cucumbers, peppers, eggplant and other greenhouse crops that require pollinators. However, do not use the bumblebees as pollinators in greenhouses, they are extremely useful in pollinating in open spaces, for example in early flowering fruit trees because they, just like solitary bees, fly out at much lower temperatures than the honey bee species.
In the Netherlands, bumblebees are used in targeted farming since 1988 when they were present in only 3% of the acreage of crops of tomatoes. In 1991 they were pollinating even at 95%, and in 1992 this figure is rounded off to 100% of the area of crop tomatoes. Today in Europe there is no country in which the pollination of crops with bumblebees is unknown.
Source: http://www.agroklub.com/pcelarstvo/bumbari-najbolji-staklenicki-oprasivaci/20805/
Image: http://www.zivotinje.rs/slike/itemImg/1432588185e-bee-and-purple-flowers-July-4-2011.jpg