Wild bees are in decline across the United States and this can be traced back to human causes. From 2008 to 2013 wild bee populations roughly declined by 23 percent, according to Taylor Ricketts, ecologist at the University of Vermont. Urbanization has taken over the bees natural habitat and forced them to find other places to live in smaller natural areas or attempt to live amongst humans. In addition to increased urbanization, the use of insecticides is contributing to the decline in bee populations. Even when applied correctly, bees still come into contact with these chemicals when pollinating. There are 11 states with the greatest declines in populations, Ohio being one of them, illustrated by the figure below.
Part of this problem can be described as colony collapse disorder. According to the Environmental Protection Agency, this is when the worker bees disappear, or die off, and leave behind the queen with nurser bees to take care of the hive. Some causes for this are not human caused, like pest varrora mite or the gut parasite nosema. But other causes can be traced back to humans including pesticide use and stress from habitat changes.
There are measures you can take to help bees survive. You can provide a dense area of blooming flowers in your yard to provde nectar. Avoid ornamental flowers as these do not produce enough nectar. Good options include sunflowers, clover, and crocus. You can also purchase organic food because this does not support the use of pesticides on a large scale. The most important thing is to not use chemicals on your lawn. Traveling bees come into contact with yards across the country and the less yards that are chemically treated the better.