Nutritional value of floral pollen to bee species

Nutritional value of floral pollen to bee species

What nutrients do bees need and how do they acquire them from floral pollen?

Bee species have specialized for the past 120 million years to feed on floral pollen. Pollen is the main source of protein, fat and other micronutrients like sterols, vitamins, and minerals that bees eat. Populations of beneficial insects including wild bee species are being threatened worldwide by reduction of habitat which reduces the abundance and types of flowering plants with available pollen. From the few surveys of the nutritional value of pollen, we know that pollen nutrients vary among flowering plants, so not all are equally valuable sources of food to bees. In addition, very few studies have examined the nutritional needs of wild bee species.

This project will study the nutritional value of wild, horticultural, and agricultural plant species. In particular, the project will focus on the species of plants used in wildflower strips in agricultural mitigation schemes for habitat improvement for bees. It will also examine the nutritional requirements of the larvae of the buff-tailed bumblebee (Bombus terrestris) and the red mason bee (Osmia bicornis) using laboratory-based assays developed in Wright’s lab. By combining the chemical ecology of pollen with nutritional studies of bee development, this studentship will produce critical information about the nutritional quality of the pollen that can be used in land management schemes for the improvement of habitat for bees.

The student will collect pollen from many plant species based on an initial target list compiled by Wright, Stevenson, and their collaborators. Pollen will be analysed for important nutrients including protein, amino acids, carbohydrates, fats, and phytosterols. Using lab protocols for rearing bee larvae, the student will examine how specific proportions of these nutrients influence the survival and development of bee larvae. By doing this, we will be able to estimate how each plant species’ pollen contributes to the potential nutrition of bee populations. The survey of pollen nutrients will also enable us to advise land managers of the best plant species to put in wildflower strips to mitigate habitat and forage loss.

Aims of the Project

1) Identify the macronutrient and micronutrient composition of pollen of several flowering plants, including species used in wildflower strips in agricultural systems

2) Measure the nutritional needs of developing larvae of bumblebees and red mason bees for protein, fats, carbohydrates and sterols.

Methods to be used

Field collection of floral pollen, GC-MS, LC-MS, bee culturing, lab-based assays of nutrition

Specialised skills required by the student

Students with skills in chemistry or field ecology would be favoured.

If interested, please contact Jeri Wright Geraldine.wright@zoo.ox.ac.uk