Report: Transmission of deformed wing virus (DWV) through imported semen

Deformed wing virus (DWV) is one of the most serious honey bee diseases in the world. It contributes to major colony losses where varroa mites are present.

Australia remains free of DWV, so preventing its entry is a key biosecurity goal. At the same time, beekeepers want access to overseas honey bee genetics, especially stocks bred for varroa resistance.

This project explored whether imported drone semen could introduce DWV into Australia. Researchers inseminated Australian queens with imported New Zealand semen containing different DWV levels. The results showed that DWV-positive semen can infect queens. Higher virus levels in semen increased the chance of queen infection. These findings confirm that imported semen is a possible pathway for DWV introduction.

Researchers found no evidence that infected queens passed DWV to eggs or brood. They tested hundreds of offspring samples across two experiments, and all results were negative. This suggests that transmission from infected queens to offspring may occur less often than earlier studies indicated.

The study also found that viable DWV can remain in stored semen for at least four weeks. Researchers also identified semen samples with no detectable DWV through careful screening and testing. Antiviral treatments did not lower virus levels and are not currently a practical biosecurity option.

The research supports continued virus testing and strong import controls. It also shows that virus-free semen can be sourced, helping the industry access valuable overseas genetics while protecting Australia’s bee health status.

Read the project snapshot for Transmission of deformed wing virus (DWV) through imported semen here.