Transmission of areca palm velarivirus 1 (APV1) by Pseudococcus cryptus

Abstract

Betel palm is one of the most economically important crops in Southeast Asia. The occurrence and expansion of yellow leaf disease (YLD) have significantly impacted betel palm plantations. Our previous research demonstrated that areca palm velarivirus 1 (APV1) was associated with YLD and transmitted by Ferrisia virgata (striped mealybug), causing YLD in betel palms. This finding provides strong etiological evidence of the role played by APV1 in YLD. Controlling YLD is a pressing issue with significant challenges. One viable approach is to prevent the virus from spreading by disrupting the transmission vectors. Therefore, it is imperative to identify potential vectors of APV1. In this study, we detected APV1 in the stylet, foregut, midgut, and hindgut of Pseudococcus cryptus (cryptic mealybug) using immunocapture RT-PCR and in situ immunofluorescence localization. P. cryptus transmitted APV1 in a non-circulative, semi-persistent manner. The retention time of APV1 in P. cryptus was notably longer than that in F. virgata. Additionally, field investigations revealed that three other insects infesting betel palms also carried APV1. In summary, APV1 may also be transmitted by other mealybug species, and the lower specificity of transmission vectors makes it challenging to control the spread of this devastating disease. This work provides timely knowledge for the prevention and management of YLD.