Summary

Importation of drone semen can be an effective way for Australian beekeepers to access desirable genetics such as Varroa resistance. Semen importation removes the risk of parasitic mites, but pathogenic viruses are still a significant risk. DWV and slow bee paralysis virus (SBPV) are biosecurity threats that have not been detected in Australia and could be introduced via imported drone semen. The import policy requires virus testing to address this risk, but the challenge of sourcing virus-free stock has been a barrier to industry uptake.

Overseas studies have shown that DWV is vertically transmitted via semen but that transmission is not 100%. Further examination of DWV vertical transmission in DWV- naïve honey bees is needed to assist industry to source and successfully import drone semen.

This project will import DWV-infected semen from New Zealand and artificially inseminate DWV-naïve Australian queens, comparing a series of semen dilutions with decreasing levels of DWV. Queens will produce brood in mini-colonies inside CSIRO’s quarantine laboratory, before brood, queens and supplied workers are collected for virus testing. With this data, the project team will aim to determine a threshold level for DWV in semen below which vertical transmission does not occur. The project team will also test the feasibility of treating semen with DWV targeting agents (e.g. DWV-antibodies, double stranded RNA) to further reduce the transmission risk. In addition the project team will investigate the longer- term viability of DWV in queen spermathecae and stored semen and how this may influence transmission. The outcomes of this research will help industry to overcome the barriers to semen importation presented by virus testing, while still maintaining this important biosecurity measure.

Program

Honey Bee

Research Organisation

Commonwealth Scientific and Industrial Research Organisation (CSIRO)