The honeybee Apis mellifera contributes to Cucumber green mottle mosaic virus spread via pollination

The tobamovirus Cucumber green mottle mosaic virus (CGMMV) is efficiently transmitted between plants by mechanical contact. So far, no clear evidence has been reported regarding the transmission potential of the virus by beneficial pollinator insects. This study examined the capability of the well-known pollinator honeybee Apis mellifera to transmit CGMMV in cucurbits using melon and cucumber plants as a model. In order to provide a clear answer to that question, five experiments were designed on various scales performed under three environmental conditions. The results show that under protected cropping conditions, CGMMV is transmitted by the honeybees. The location of the beehive in relation to both the CGMMV primary inoculum source and the healthy plants during honeybee foraging plays an important role in the efficiency of CGMMV spread. Furthermore, in the presence of early stage CGMMV-inoculated plants, the efficiency of CGMMV spread to uninoculated plants placed on the honeybees’ path to the beehive may increase. To the authors’ knowledge, CGMMV transmission by honeybees has not yet been shown, and this study can be adopted for other tobamovirus related research.