Food security through insect dormancy management: using molecular physiology to optimise commercial rearing of a key UK pollinator.

Establishing food security in the face of climate change is of intense global interest, and pollinators will play a key role in achieving this objective. Agriculture cannot rely on natural pollinators alone as many species are in severe decline. Critical to enhancing pollination service resilience in the UK is identifying alternative species for commercial production. The red mason bee, Osmia rufa, is a more efficient pollinator than honey bees, and suitable for pollinating a wide range of crops, including many fruits, vegetables and oil seed rape. O. rufa is found throughout the UK, but growers have not typically had the option to use it, as it is not widely available. Currently, commercial provision is totally reliant on reclaiming artificial bee nests distributed to orchard farmers, and other users, in order to provide a population for the next year. However, this system is small scale and has fundamental problems as it is dependent on bees returning to artificial nests. It is also vulnerable to highly variable returns due to climatic conditions, bee-plant asynchrony or parasitism. In addition, this practise is continually depleting wild populations.
For large scale culturing of O. rufa to be commercially viable it is essential we understand how to manipulate the period of obligatory dormancy (diapause) within its life cycle. Diapause can last for many months and has significant time and cost implications for the mass culturing of this, and many other, important insect species. Diapause also has great utility however, as it allows us to stockpile insects in a dormant state. This enhances their 'shelf life' as well as reducing shipping related damage. Understanding what processes regulate diapause, and how to switch them on and off, will allow us to control how long bees can be stored for, and more importantly when dormant bees emerge as adults, i.e. when O. rufa can be made available to farmers that have crops flowering at different times of year in different regions of the UK. Virtually all temperate insects enter diapause, so O. rufa has great value as a model relevant to the commercial production of other important pollinator or biocontrol species.
The foundation of this project is the partnership between experts in insect dormancy at the University of Birmingham, and the company Biobest, which has over 25 years of experience in commercial provision of insects. Our ultimate goal is to develop a culturing method that will allow healthy O. rufa to be made available 'off the shelf' to farmers throughout the UK whenever required for pollination. Critical to achieving this goal is understanding how to rear the bees in a lab or greenhouse environment and control their life cycle. This project will use state-of-the-art techniques to investigate the molecular and physiological processes underpinning diapause, and so identify ways of enhancing cold storage within the dormant state, as well as controlling synchronous diapause termination on demand. Finally, we also want to ensure that the bees provided are well suited to the particular environmental conditions whenever and wherever they are released.

In summary, the key objectives of this project are to: 1. Establish a culturing system that will allow continuous production of healthy/disease free O. rufa. 2. Characterise the molecular and physiological processes that underpin diapause to identify targets for: i) diapause termination, e.g. through temperature or chemical treatment, to end diapause on demand and so produce staggered, but synchronous bee populations to coincide with different crops in different regions; and ii) enhancing cold tolerance, e.g. through different acclimation regimes or dietary supplements to improve survival of long-term storage. 3. Compare diapause characteristics and pollinator performance of O. rufa populations from southern, central and northern UK sites, to determine if establishing different regional 'types' has commercial value.