Bees pollination and the environment Summary of CyberSTEM presentation

We will be looking at the European honey bee and an Australian native bee as examples of pollinators

We will talk about:1) Scanning electron microscopy2) Sample preparation3) Bee form and function4) Pollination issues

Text and images by the Centre for Microscopy & Microanalysis, University of Queensland, Australia, August 2007

Bees feed at flowers, gathering nectar and pollen. How does this affect pollination?

European honey beeApis mellifera

Australian native beeTrigona carbonaria

Some plants are wind-pollinated (e.g. grasses including grains) or self-pollinate, but others require pollen transfer by organisms: beetles; butterflies; birds; and of course bees.

Almonds and blueberries rely entirely on pollinators. Other crops set little fruit without: pumpkin; cherry; kiwi; apple; plum; apricot; peach…

Mango, cashew, Macadamia, papya also rely on pollination, as do many native plants.

Reference: Cunningham, S.A., FitzGibbon, F., Heard, T.A. (2002) The future of pollinators for Australian agriculture. Australian Journal of Agricultural Research 53: 893-900.

How do bees pollinate plants?

Do they have specialised adaptations or structures to assist?

How do they find flowers?

If we look at bees under the microscope we can answer these questions

Bees are dried when dead then mounted and coated with platinum

Native bee

Sample mounts

European honey bee

Sample preparation

5 mm

The following images are of bees imaged using using a scanning electron microscope – electrons provide monochrome images.

Please refer to the separate background PowerPoint presentation for theory and background related directly to how scanning electron microscopes work

Head of a honey bee

Note hairs occur even on the eye.

Why so may hairs?

What is special about the hairs on bees?

Eye

Antenna

Branched hairs catch pollen

Hairs on the head of a honey bee

Pollen

Pollen

A honey bee antenna.What is the role of the antenna?Note the stubby spines and round plaques – what is their purpose?

Pollen basket with some pollen: honey bee Hind leg

Head of a native bee: Trigona carbonaria

Antenna

Eye

What is different about this bee?

Compare it with the honey bee head

Hairs on the head of a native bee

Native bee antenna = the nose

Empty pollen basket on leg of native bee

Full pollen basket: native bee

Pollen comb on front leg of native bee

Leg

Pollen

Wing of native bee

Note hairs and pollen

Abdomen of native bee

Note hairs

Pollen clusters from legs of European honey bees: each contains millions of pollen grains. Light-based image

What do the different colours tell us?