ReviewofthepesticidesregisteredonmajornectarcropsinChinaandtheprimaryriskassessmentoftheinsecticidestohoneybees

Pesticides currently registered on the major nectar crops in China were reviewed. Then primary risk assessments of 61 insecticides registered on these nectar crops such as chlorpyrifos, imidacloprid and etc. to honey bees were conducted according to the existing risk assessment method. The results showed that among the 58 insecticides which were applied by spraying, the risk quotient (RQ) values of 35 insecticides were all greater than one, which meant the risk of these insecticides to honey bees was unacceptable. And among 6 systemic insecticides which were applied through soil or seed treatment, the RQ values of 5 insecticides were greater than one, which meant the risk to honey bees was unacceptable, and the only pesticide of this type which had low risk to bees was chlorantraniliprole. But it is noteworthy that the exposure assessments in the current assessment procedure was based on the maximum single application rates of the pesticides and the following issues was not considered: the degradation of pesticides in pollen, nectar, the washoff of pesticides from foliar, the relation between application time and the plant flowering period and etc. Therefore the assessment results were rather conservative. These findings can be treated as references for the reasonable usage and management of these insecticides and also suggest that the primary risk assessment procedure of pesticide to bees currently used in China could be refined.