First report on the presence of the huanglongbing vectors in Ghana

Abstract

Abstract As significant threats to global citrus production, Diaphorina citri (Kuwayama; Hemiptera: Liviidae) and Trioza erytreae (Del Guercio; Hemiptera: Triozidae) have caused considerable losses to citrus trees globally. Diaphorina citri vectors “Candidatus Liberibacter asiaticus” and “Ca. L. americanus”, the causative agents implicated in Asian Huanglongbing (HLB), whereas T. erytreae transmits “Ca. L. africanus”, the pathogen responsible for the African form of the disease. Though HLB is the deadliest disease of citrus wherever it occurs, information on the occurrence and geographical distribution of its vectors in Africa is limited. In recent surveys to determine if HLB vectors are present in Ghana, we observed eggs, nymphs, and adults of insects suspected to be D. citri and T. erytreae. Using morphological traits and DNA analyses, the identity of the adult and nymphal stages of the suspected insects was confirmed to be D. citri and T. erytreae, respectively. Individuals of D. citri and T. erytreae were examined using qPCR for CLaf, CLam, and CLas, but none of them tested appositive for any of the Liberibacter species. Herein we report, for the first time, the presence of D. citri and T. erytreae in Ghana (West Africa). We discuss the implications of this new threat to the citrus industry to formulate appropriate management strategies.