Great variability in the infection rate of 'Candidatus Liberibacter asiaticus' in field populations of Diaphorina citri (Hemiptera: Liviidae) in Florida

Citrus growers, researchers, and policy makers are commonly interested in knowing the rate of CLas pathogen infection in populations of Diaphorina citri Kuwayama (Hemiptera: Liviidae) in Florida and elsewhere. Given that HLB is widespread across Florida, a common presumption is that nearly 100% of D. citri are currently carrying the pathogen. We investigated this presumption and found that instead, in 2014 - nearly a decade after HLB was officially detected in Florida - the rate of CLas infection in populations of D. citri varies widely between commercial citrus growing locations. Across the state, infection rates ranged from 37.5 to 100%, with an average of 68.8% (SD 25.3%). We suggest that there may be yet unknown factors responsible for the lower rates of infection found at certain sites, particularly in South Florida, that may be useful for management of this disease when determined. Our future goal is to identify the potential factors that affect CLas infection rates within field populations of D. citri across Florida under varying management practices and geographical locations.