Improved methods for bee development and control of bee mites in Papua New Guinea

• Department of Agriculture and Livestock, Papua New Guinea

Previous findings included that:

the Asian hive bee is ideally suited to the PNG environment and will spread throughout the PNG mainland;

the mite V. jacobsoni, whose natural host is the Asian hive bee, cannot reproduce on the European honey bee in PNG and will not present a serious problem for beekeeping there;

spread of T. clareae, whose natural host is the giant honey bee Apis dorsata, is via feral European honey bee populations and is restricted to the Highlands;

in the absence of control with chemical acaricides, invasion of a European honey bee colony by T. clareae invariably leads to death of the colony; and

chemical control of T. clareae in hived colonies would be possible but expensive and, as the mite is apparently killing all feral honey bee colonies, eradication appears a realistic option.

This project builds on a previous ACIAR project which was initiated following the discovery in 1986 of the exotic Asian hive bee Apis cerana and the parasitic bee mites Varroa jacobsoni and Tropilaelaps clareae in Papua New Guinea. Major concerns were the threat the mites posed to the PNG beekeeping industry based on the European honey bee Apis mellifera and the increased risk that the Asian bee and the mites could enter Australia.

The new project will address further research questions to ensure an effective response to the presence of the Asian hive bee and the bee mites in PNG.

Monitoring will be undertaken to estimate the time taken for T. clareae to reach the main beekeeping areas in the Eastern Highlands and how well the Asian hive bee is becoming established in different environments. Further monitoring will show whether the mite V. jacobsoni retains its inability to reproduce in European honey bee colonies. To date, PNG is the only country where a total incapacity to reproduce has been reported.

Studies are planned to test whether the PNG bees are genetically resistant to V. jacobsoni. These will include collaborative work in Germany where the mite readily reproduces in honey bee colonies. Other research will look at the possibility that abnormal levels of a juvenile hormone are responsible for the non-reproduction and examine isolates of V. jacobsoni collected from various countries for genetic differences.

In addition, field work in Indonesia to study the life cycle of T. clareae on its natural host, the giant honey bee will be undertaken. This may suggest possible control methods. The life cycle of a third mite, Varroa underwoodi, which was detected in one Asian hive bee colony and one European honey bee colony in PNG in December 1993, will also be studied.