Incursions of plant viral pathogens are a primary concern for horticulture as they can significantly impact crop yields and require expensive management. Early detection of plant viruses is critical for effective plant biosecurity because it enables growers to respond quickly and limit their spread. However, current surveillance methods relying on ELISA and PCR testing of plant material can only operate at a limited scale. It quickly becomes unfeasible to test large numbers of samples for area-wide surveillance of multiple viruses. Recent advances in next-generation sequencing (NGS) technologies have greatly improved our surveillance capability and its value is demonstrated for screening plant material for viral pathogens. However, while NGS can improve detection, it doesn’t necessarily address the issue of sampling effort needed to achieve early detection. The solution is to couple NGS with a method of constant surveillance and sampling from potentially infected plants. We propose that when managed honeybee (Apis mellifera) hives are brought to flowering crops to deliver essential pollination services, they can also provide valuable surveillance by effectively “sampling” entire crops as they collect pollen and nectar. Combining the ability of honey bees to create a representative sample from a large number of plants with the sensitivity of NGS offers a powerful system for early detection of plant viruses.
We present a novel approach to plant biosecurity where NGS virus detection in honeybees was found to provide earlier detection of plant virus incursions in Australia than current surveillance programs. In 2013-2014 a national virus survey of honey bees was conducted, which used NGS screening of pooled honeybee samples across Australia. This NGS data simultaneously identified multiple plant viruses in these samples and retrospectively showed the presence of cucumber green mottle mosaic virus (CGMMV) in several states of Australia before being detected from diseased plant material.