Conserving our bees

The title of this article, and the similar title of the IBRA conference held in London, reflects a growing awareness and interest in the demise of the world's wild bees, and the impact this may have on other wildlife, ecosystems (including agroecosystems) and the world's economy. Invertebrate Red Data Book and analagous lists invariably contain a high percentage of the bee species of a geographic location. As an example, over 50% of the bee species in the state of Baden Württemberg, SW Germany, are considered to be under threat. The situation seems little better elsewhere. Many bee species appear threatened with extinction, with the general consensus of opinion falling on humans as the culprits, through their degradation and destruction of habitats.

I see three major arguments for the conservation of wild bees, namely:

Bees are of conservation value in their own right, as a component of the world's biodiversity.
Bees are important components of natural ecosystems and play a big role in their functioning. As such, they are important for the conservation, directly or indirectly, of other wildlife.
Bees are important in agriculture as crop pollinators.

Though there may be much overlap in all three arguments, and though advocates of wild bee conservation may variously use these arguments in the defence of bees, by simplifying the arguments it may be possible to highlight their essential elements and thereby indicate where we require extra input, in terms of discussion or research, to understand how to reduce, even about-turn the demise of wild bees. I shall deal with each in turn, and hope to highlight a few salient points where information is lacking.

Subsumed within this argument for bee conservation are those elements based on the maintenance of bee biodiversity for bees' intrinsic or aesthetic appeal. There is a diversity of 'biodiversity' definitions so that priorities for one bee conservationist may not be those of another. Do we aim to conserve species, or any and all local forms of a species? Somewhat related to this question, should conservation strategies be set on a country-by-country basis or on a global basis?

Going back a few steps in the development of the argument, there is a need to know which species are rare, and which are changing in abundance. Long-term monitoring is the key element here. But monitoring can be expensive, and initial results may not suggest cost-efficiency. However, monitoring is vital. The monitoring of Britain's bumble bees, partially co-ordinated through IBRA, has revealed a very worrying decline in many formerly widespread bees; it is a good example of the benefits of such work. Appropriate land management strategies then need to be implemented which favour threatened bees.

Numerous inventories of bee species have already been undertaken in both temperate and tropical locations, in the past often without an explicit conservation function. Results have been published in a disparate literature. Co-ordination of studies and collation of past records would be of immense benefit, and help to target scarce resources on species in need of protection.

Given the major role that bees play in numerous terrestrial ecosystems as pollinators of flowering plants they are often considered as 'keystone' species, ensuring the continued reproduction and survival of the plants and other organisms that live on these primary producers. However, a few plant species may serve the needs of most wild bee species, and plants may be effectively pollinated by a diversity of agents, thus reducing any individual bee's role in ecosystem functioning. It is logically difficult to demonstrate the importance of any one bee species within an ecosystem in which plant-pollinator interactions are diffuse. But identification of a location's critical bee or plant species in maintaining a diverse plant or bee assemblage, respectively, would be useful. Bees, or groups of bee species (e.g. cleptoparasitic bee species), could then be used as monitors or 'indicator species' of 'habitat integrity'. But does a diverse bee assemblage equate with a diverse flora and wider fauna (birds, mammals, butterflies, beetles etc.)? Evidence from other groups of organisms suggests not.

An oft-used argument for the conservation of wild bees is that they may act, now or in the future, as economically important pollinators of crop plants. Indeed, with dependence of much commercial pollination on one bee species Apis mellifera, and threats posed to it such as miticide-tolerant Varroa jacobsoni, there will be long-term economic benefits to developing other bee species as commercial pollinators and to maintaining a diversity of potential wild bee pollinators. The value and management of alternative pollinators is attracting growing interest across the world.

Major changes in land use due to economic and political considerations and changing conservation strategies are around the corner; within the EU for example, these arise from changes in farming subsidies (CAP-reforms), the EU Habitats Directive and the UN Biodiversity Treaty. These changes could have major implications for wild bees. Politicans and policy-makers need to be informed of the value and importance of bees if we are to avoid the continued demise of bees. We must ensure that we are suitably armed with that information. I hope that my idiosynchratic points and questions will generate further thought and discussion as to the exact form and nature of that information.

The numbers given at the end of references denote entries in Apicultural Abstracts.

1. CONSERVING EUROPE'S BEES (1995) A symposium organized by IBRA and the Linnean Society of London, 6-7 April 1995, London, UK.

2. DAY, M C (1991) Towards the conservation of aculeate Hymenoptera in Europe: an outline of the care for recognition of the high value of Hymenoptera Aculeata as indicators of biotope integrity and diversity, with relevant examples and proposals for conservation actions. Nature and Enviornment Series No. 51. Commission of the EC; Strassbourg, Germany; 44 pp.

3. ELLIS, W N; WLLIS, A A C (1993) To make a meadow it takes a clover and a bee: the entomophilous flora of NW Europe and its insects. Bijdiagen tot de Dierkunde 63(4): 193-220.

4. ELSE, G R; SPOONER, G M (1987) Hymenoptera: Aculeata-ants, bees and wasps. In Shirt, D B British red data books. 2. Insects. Nature Conservancy Council for England; Peterborough, UK.

5. FALK, S (1991) A review of the scarce and threatened bees, wasps and ants of Great Britain. Research and Survey in Nature Conservation No. 35. Nature Conservancy Council for England; Peterborough, UK; 344 pp. 738/92

6. IBRA; ITE (1980) Atlas of the bumblebees of the British Isles. Institute of Terrestrial Ecology and International Bee Research Association; Cambridge, UK; 32 pp.1142/80

7. INTERNATIONAL WORKSHOP ON NON-APIS BEES AND THEIR ROLE AS CROP POLLINATORS (1992) 10-13 August 1992, Logan, Utah, USA.

9. PRENDERGAST, J R; QUINN, R M; LANSTON, J H; EVERSHAM, B C; GIBBONS, D W (1993) Rare species, the coincidence of diversity hotspots and conservation strategies. Nature 365: 335-337.

10. TORCHIO, P F (1994) The present status and future prospects of non-social bees as crop pollinators. Bee World 75(2): 49-53. 1494/94

11. WESTRICH, P (1989) Die Wildbienen Baden Württembergs. Eugen Ulmer; Stuttgart, Germany; 972 pp. 381/90

12. WILLIAMS, P H (1982) The distribution and decline of British bumble bees (Bombus Latr.) Journal of Apicultural Research 21(4): 236-245. 767/83

13. WILLIAMS, I H; CORBET, S A; OSBORNE, J L (1991) Beekeeping, wild bees and pollination in the European Community. Bee World 72(4): 170-180. 446/92

Robert Paxton
Universitat Tubingen, Germany

A book containing the papers presented at this conference, 'The Conservation of Bees', is available from the IBRA bookshop.