New Zealand Colony Loss Survey shows ongoing trend in overall honey bee colony loss
A report on the New Zealand Colony Loss Survey for 2018 has been released highlighting an increase in colony losses in most regions throughout New Zealand, with the Upper North Island having the highest colony loss rates.
The Ministry for Primary Industries (MPI) has today published the report, revealing beekeepers have reported a higher hive loss rate than previous years in four out of the six broad areas of the country.
Manaaki Whenua – Landcare Research researchers conducted the annual online survey on behalf of the beekeeping industry and MPI. More than 3,600 registered beekeepers (47% of NZ beekeepers) participated in the survey, providing information about the health of their bees and relevant management practices.
This year’s results estimate the national-level overall loss rates for winter 2018 at 10.2%, up from 2016 (9.7%) and 2015 (8.4%), but statistically indistinguishable from 2017 (9.6%). However, further analysis demonstrates a positive time trend in winter losses at the national level.
The highest colony loss rates occurred in the Upper North Island (12.8%) and Middle South Island (11.4%), while the lowest were registered in the Lower North Island (8.1%).
Trend analysis reveals that overall loss rates have increased since 2016 in the Upper North Island and across the South Island, while decreasing in the Middle North Island and Lower North Island.
Average loss rates were significantly higher for non-commercial beekeepers than for semi-commercial and commercial beekeepers.
Leading causes of colony losses include queen problems (35.5%), suspected varroa and related complications (19.5%), suspected starvation (12.1%), and wasps (12.1%).
Most commonly, queen problems were attributed to drone-laying queens and queen failure – but both of these issues were more pronounced among older rather than younger queens.
The Lower South Island reported less formal monitoring of varroa than other regions and the report showed that, among beekeepers who treat varroa, Amitraz and Flumetrin are the most common treatments by a wide margin.
The Colony Loss survey has been conducted annually since 2015 and the questionnaire is based on the international COLOSS survey, but has been adapted to include topics of specific interest to New Zealand beekeepers.
Full survey results: www.landcareresearch.co.nz/bee-health
Full report: www.mpi.govt.nz/document-vault/16711