No one knows the number of individual honeybees and other bee species in Ohio although the Department of Agriculture records honeybee colony numbers. But, it is important for growers to watch the changes in bee populations from area to area and from year to year.
The number of colonies of honeybees and the number of bees in each hive can be influenced by bee diseases, pesticide sprays, poor nectar flows, and seasonal changes. To control diseases, the Ohio Department of Agriculture provides for manditory registration of colonies of honeybees and inspects these bees for disease. As a result of the department's efforts, the incidence of American foul brood-diseased colonies in Ohio has been less than 1 percent since 1962.
A single, wide-scale pesticide application for control of a harmful pest can weaken or destroy many colonies. This might follow heavy rains and the appearance of dense mosquito populations carrying disease. Less dramatic, but equally important, is the year to year spraying of agricultural crops in certain areas. Sweet corn is regularly sprayed when in bloom, and many bees foraging for pollen are destroyed as a result. Intensely farmed lands are often nearly devoid of bees-both native bees and honeybees-because of continual insecticide applications. Honeybee rental is particularly important in these areas for crop pollination.
Drought or prolonged periods of rain, cool temperatures, and early frosts, all limit nectar production by plants. In these cases, the beekeeper may need to feed his bees.
Increasing interest in conserving the environment should include programs designed to preserve non-honey bee pollinators that live in nearly every part of Ohio. These insects include bumble bees, mining bees, sweat bees, digger bees, and leaf cutter bees. Their contribution to agriculture is poorly understood, and their contribution to the pollination of seed and fruit for wildlife is unknown. But we do know that many techniques of modern agriculture severely reduce their populations.
The reasons are simple. Modern farming methods have destroyed the homes of these insects. They nest in the soil or in hollow twigs of sumac, brambles, etc. Clean cultivation, elimination of brushy areas and fence rows, high use of pesticides during most of the growing season (such as in orchards), all contribute to the reduction in numbers of native bees. Not only are the homes for these insects destroyed but also the flowers they visit.
Current agricultural methods also make some areas profitable for bees but only for a short period of time. For example, an apple orchard might be useful to bees only 5 to 10 days out of the year. The rest of the year, assuming the orchardist keeps the ground-cover mowed and the trees sprayed, this land has little value to native bees or honeybees.
Increased diversity of crops on farms will help encourage bees to increase in populations in a particular area. Ditch plantings, waterways, small woodlots, landscape plantings, wildlife plantings, and other programs incorporated into an overall farm plan which includes legumes, annuals attractive to bees, and flowering trees and shrubs will serve to give the bees a nectar and pollen source throughout the growing season.
Instead of removing fence rows, farmers might add trees and shrubs attractive to bees. A badly eroded area might be planted to legumes and flowering trees and shrubs, and converted into a wildlife refuge. Instead of solid grass waterways on his farm, a farmer may select a seed mixture including legumes attractive to bees.
Such planned diversity in intensely farmed areas will increase bee forage and increase native bee populations, thus giving the grower a reservoir of bee pollinators ready to work his crops when they are needed. There is considerable advantage to this type of program for the beekeeper as well.