ToBRFV Transmission: Blame ourselves, not insects!

By Alberto Reggiani

With the Tomato Brown Rugose Fruit Virus (ToBRFV) still a significant concern for growers, research has appeared on the role of insects that may spread the virus. Indeed, some studies have shown that bumblebees and the tomato leaf miner, Tuta absoluta, have the ability to spread the virus if they are exposed. But it’s important to clarify some misconceptions and highlight the real culprits behind the spread of this virus.

It's true, bumblebees, essential for pollination, can carry the virus from infected to healthy plants. Similarly, Tuta absoluta larvae can come into contact with the virus while feeding on infected tissues, leading to potential transmission during their life cycle.

However, their role is relatively minor compared to other transmission methods. The efficiency of insect-mediated transmission is low, and the primary concern lies elsewhere: human activity.

Practices such as harvesting, transplanting, grafting and pruning are major factors in disease transmission. Direct contact with infected plants, as well as indirect contact through tools, equipment, and even clothing, poses a much greater risk than insects.

In fact, the movement of infected plant material, particularly through human intervention and transmission via infected seeds are the leading cause of ToBRFV outbreaks. This highlights the need for stringent hygiene protocols in agricultural practices and zero tolerance concerning seed production.

And it explains why we meticulously disinfect and test all our seeds.

Sure, it does not hurt to fight the tomato leaf miner as well, but bumblebees are very important for pollination – and thus for agriculture and nature alike. So, let’s not blame the insects, but step up our hygiene measures and quality control.