Development of a risk-indicator for the pressure of crop protection products on solitary bees in apple

Today, the importance of solitary bees is not well known. Indicators that measure the pressure of pesticides on these bees lack. "To measure is to know"; if the indicator shows that certain plant protection products have side effects, a number of effective mitigation measures can be put forward to protect these bees. As case study is chosen in apple, where these solitary bees are indispensable.