It appears that bees leave to look for nectar and pollen and never return to their colonies. The problem is so severe that researchers are calling it the 'colony collapse disorder'.
Researchers are not sure what is going on. They are however, investigating a couple of theories. One of them is that the bees are stressed because they are being made to pollinate more. This in turn has lowered their resistance to diseases, causing them to die early.
A second theory being investigated is the effect of insecticides on bees. Colony keepers are using insecticides to kill mites (little insects that leech off honeybees). Researchers believe this has resulted in shortening the lifespan of queen bees and also reduced its ability to give birth to worker bees.
Whatever the reason, the disappearance of the honeybees is a cause for great concern for farmers across the United States. One of the reasons is the lower supply of honey. The other, even bigger cause for concern is pollination. Honeybees pollinate most fruit orchards, grain fields and vegetable crops. Therefore, if the mystery of the vanishing honeybees is not solved, our fruit and vegetable supply may be affected. Some fruits and vegetables may become more expensive; others may simply not be able to grow. Stay tuned for updates on further developments on this story.
Sources: scienceray.com, cnn.com