slide 14 of 16

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Slide 14 of 18

Notes:

In the early years of alfalfa leafcutting bee management, Northwest growers could obtain an increase in their bee populations, which they would sell to neighbors. This ended when chalkbrood, a fungal disease of leafcutting bees, was discovered in the early 1970s. Although chalkbrood mortality has declined, high larval mortality from a variety of factors means that there is not enough local bee reproduction to meet grower demand for large bee populations. Because of the high larval mortality, northwest growers turned to Canadian seed growers in the 1970s to supply large bee populations for pollination. Canadians are able to increase their bee populations 1.5 – 2 fold over initial populations. In establishing the Pollination Ecology Program at UI, growers sought solutions to numerous bee management problems, like chalkbrood and pollen balls, which prevent them from producing sustainable bee yields.