Authors: Xue Dong Chen Torrence A Gill Kirsten S PelzStelinski Lukasz L Stelinski
Publish Date: 2017/01/23
Volume: 26, Issue: 3, Pages: 351-359
Abstract
The Asian citrus psyllid Diaphorina citri Kuwayama Hemiptera Liviidae is a major pest of citrus trees worldwide A wide variety of insecticides are used to manage D citri populations within citrus groves in Florida However in areas shared by citrus growers and beekeepers the use of insecticides may increase the risks of Apis mellifera L Hymenoptera Apidae loss and contaminated honey The objective of this research was to determine the environmental toxicity of insecticides spanning five different modes of action used to control D citri to A mellifera The insecticides investigated were imidacloprid fenpropathrin dimethoate spinetoram and diflubenzuron In laboratory experiments LD50 values were determined and ranged from 010 to 053 ng/μl for imidacloprid fenpropathrin dimethoate and spinetoram LD50 values for diflubenzuron were 1000 ng/μl Also a hazard quotient was determined and ranged from 113043 to 1089327 for imidacloprid fenpropathrin dimethoate and spinetoram This quotient was 0447 for diflubenzuron In field experiments residual activity of fenpropathrin and dimethoate applied to citrus caused significant mortality of A mellifera 3 and 7 days after application Spinetoram and imidacloprid were moderately toxic to A mellifera at the recommended rates for D citri Diflubenzuron was not toxic to A mellifera in the field as compared with untreated control plots Phenoloxidase PO activity of A mellifera was higher than in untreated controls when A mellifera were exposed to 14 days old residues The results indicate that diflubenzuron may be safe to apply in citrus when A mellifera are foraging while most insecticides used for management of D citri in citrus are likely hazardous under various exposure scenarios
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