Bumblebee Pollination

A team at Zonda Beneficials Ltd is researching how to keep bumblebee hives pollinating for longer, by using a pheromone that mimics one excreted by the queen bumblebee. It is part of a wider research and development programme aiming to contribute towards the long-term sustainability of the horticulture sector. MPI is contributing $160,000 towards the $400,000 project through its Sustainable Food and Fibre Futures fund.

The members of the team from Zonda Beneficials include Roelf Schreuder (Director of the company and chairperson of the project); Dr Gunjan Gera (Production and R&D manager, and lead researcher of this project), Daniel Neil (research assistant) and Dr Jo Stephens (an independent consultant).

The research project will continue for three years and has three main objectives:

• To improve the performance of commercial bumblebee hives
• To develop a mass rearing programme for the predatory mite, A. limonicus
• To improve an existing mass breeding programme for the predatory mite (P. persimilis)

Dr Gera explains that in order to improve the performance of commercial bumblebee hives for the horticulture sector in New Zealand, they will focus on extending the life span of the commercial bumblebee colony. 

Bumblebees are crucial for their pollination services of many important and everyday varieties of produce, such as tomatoes, blueberries, raspberries, blackberries, and strawberries. They are generally used in glasshouses and on covered crops, as bumblebees tend to travel only about 200 metres from their hive and don’t mind enclosed spaces, as opposed to honey bees that tend to roam further afield to find their pollen and nectar sources.

The queen of a commercial bumblebee hive in the field lives for approximately 10 weeks and the hive winds down once the queen dies. Dr Jo Stephens explains, “With fewer worker bees, the hives can appear less active when compared to honey bees and there can be variation in vigour and productiveness”. 

The research is exploring ways to allow the hive to continue to survive and pollinate crops even after the queen dies. The project is exploring the use of an imported pheromone compound, in conjunction with the queen bees. One of the challenges is to develop a way of dispersing the compound around the hive. This technology is in its infancy overseas so there is much ‘trial and error’ involved, explains Dr Gera.

Another aspect of the work will be screening bumblebees for diseases and other health parameters to improve the overall health of the hives, which in turn will help bees perform better and produce better fruit.

Bumblebees were introduced to New Zealand from the United Kingdom by early pioneers, so there is limited genetic diversity in bee populations here. In this study bumblebees will also be tested for indicators associated with inbreeding, and importing genetics will be considered if necessary.

The second objective of this research project is to mass-breed a predatory mite (native to New Zealand) that could effectively deal with a wide range of pests, including aphids and white fly. Currently, New Zealand growers can only import these mites (Amblydromalus limonicus, known as ‘Limonica’) from the Netherlands where they have been successfully bred for some time. This is expensive, time-consuming, and carries the risk of supply shortages. These mites are highly effective at eating many New Zealand horticultural pests but are difficult to breed. It took a Netherlands company 15 years to create reliable production of the mite.

Dr Gera says, “If we are able to breed them successfully it will be a milestone for the NZ horticulture industry”. With ‘Limonica’ being a native species, there are no biosecurity or ‘new organism’ restrictions, and mass production in New Zealand would benefit growers .

In the third aspect of this research project, Zonda is aiming to improve the existing breeding programme for another predatory mite, P. persimilis (brand name ‘Spidex’). This is a very efficient predator of two spotted mites, but their continuous supply to the growers is hindered by unpredictable environmental factors. Therefore, a modification in the existing system is required to create a uniform supply throughout the year.

This project could help increase the productivity of bumblebee hives dramatically. MPI Investment Programmes director Steve Penno says, “Enhancing bumblebee activity would mean better pollination for growers, which means higher yields and better quality produce”.

www.opportunitygrowshere.co.nz

Showdown Productions Ltd.   Rural Delivery Series 16 2021