Summary

Nosema (N. apis and N. ceranae) and viruses contribute significantly to the pathogen load of honeybee colonies but their cryptic nature leaves them largely unmanaged by beekeepers. The current RIRDC project PRJ-8450 found a high prevalence of Nosema and viruses across Australia, particularly during almond pollination. Better management of Nosema and viruses is needed to minimise their impact on hive productivity and pollination activity. This project will deliver improved management of these important pathogens in two ways. Firstly, by testing the influence of different autumn floral types and an autumn pollen feeding strategy to reduce levels of N. apis, N. ceranae and viruses during almond pollination. Secondly, by directly testing the effects of pollen on virus infections using lab infected honeybees in experimental cages. This project is a logical extension of previous studies on Nosema and viruses, which is needed to address ongoing issues with these pathogens.
To demonstrate whether improved autumn nutrition can reduce pathogen loads during almond pollination I will conduct a field experiment in collaboration with 5-10 commercial beekeepers from SA, VIC and NSW involved in almond pollination. Hives using different autumn floral types and given pollen supplements will be compared for pathogen load and honey yield. Pathogen loads of individual hives will be quantified at pre-treatment in Feb 2016 and post-treatment at winter shutdown in May, pre-almonds in Aug, post-almonds in Aug, and post-canola in Oct. Honey yields will be determined in Dec 2016. I hypothesise that improved management of autumn nutrition can deliver reduced pathogen loads in late winter and benefit pollination hives. To investigate the effects of pollen on virus infection I will use lab assays to provide adult bees with pollen and experimentally infected them with sacbrood virus, with the hypothesis that pollen fed bees will have reduced virus infections.

Program

Honey Bee

Research Organisation

CSIRO

Objective Summary

1. Demonstrate the effects of autumn nutrition on hive pathogen loads in late winter
2. Determine the effects of pollen intake on virus replication in honeybees