Using Rose Bengal photosensitizer for controlling Aphis gossypii and reducing transmission of zucchini yellow mosaic virus on squash plants

Abstract The cotton aphid, Aphis gossypii , exhibits the highest transmission rate of zucchini yellow mosaic virus (ZYMV). This study aimed to evaluate the lethal effect of Rose Bengal photosensitizer (RBPS) on aphids and transmission of ZYMV on squash plants. Five concentrations of 0.1, 1, 10, 100, and 1000 ppm were used on adults of a virus-free aphid. Results confirmed that the highest mortality (100%) occurred after 72h of treatment with a concentration of 1000 ppm, where LC 50 was 1.66 and 0.0807 ppm after 24h and 72h, respectively under sunlight exposure. The reverse transcription polymerase chain reaction (RT-PCR) of the virus isolate confirmed the presence of ZYMV. A sequence analysis was carried out and given a GenBank accession number PZ289840.1. Transmission studies showed that after pre-acquisition treatment by RBPS, the ability of aphids to pick up the virus was reduced to 23.3% with a 74.3% transmission reduction. In the pre-inoculation treatment, RBPS reduced the efficiency of A. gossypii in the virus transmission to 40.0% with a reduction of 55.6%. Using RBPS before both virus acquisition and inoculation gave the lowest transmission rate (13.3%) and highest reduction (86.7%). This method will be promising for controlling virus spread by aphids under the field conditions.