Investigation of host plant contact withDiaphorina citri(Hemipreta: Psyllidae) by detectingD. citri-derived environmental DNA

Abstract

Citrus greening (Huanglongbing) disease has serious impacts on citrus production. Field monitoring of the Asian citrus psyllidDiaphorina citri(Hemiptera: Psyllidae), a vector of citrus greening disease, is essential to prevent the invasion and spread of this disease. This study reported a new method for determining the presence ofD. citriand traces of contact with host plants by collecting leaves of host plants from the survey area and detecting the environmental DNA (eDNA) derived fromD. citri. The results showed that the method can determine the presence ofD. citri.AsD. citri-derived eDNA is contained in DNA solutions of plants with a history of contact withD. citri, we succeeded in detecting not only genes conserved inD. citrimitochondria but also genes ofD. citrisymbiont organisms consisting ofWolbachia,Wolbachiaphage,CandidatusCarsonella sp., andCandidatusProfftella sp.Diaphorina citri-derived eDNA could be detected in host plants even after only 10 min of contact withD. citriand could still be detected 6 months after contact. This technology has the potential to traceD. citrifrom their traces without individual detection and is expected to greatly contribute to the early detection and invasion warning of citrus greening disease in the future.