Praz Christophe

Between Theory and Praxis: Conservation of Solitary Bees 

Project Number: CH-4949
Project Type: Research_Project
Project Duration: 01/01/2011 - 12/31/2011 project completed
Funding Source: other ,
Leading Institution: Université Neuchâchtel
Project Leader: Dr. Christophe Praz
Research Leader
Entomologie évolutive
Institut de Biologie
Université de Neuchâtel
Rue Emile-Argand 11
2000 Neuchâtel
Phone: v ; +41 (0) 32 718 3000
FAX: +41 (0) 32 718 3001
e-Mail: christophe.praz(at)unine.ch
http://www2.unine.ch/Jahia/site/biol/op/edit/pid/4606

related to this project.
for which the project has a relevance.


Research Areas:
Biodiversity

Disciplines:
general biology

Keywords:
Solitary bees, systematics, diversity, ecology, limiting factor

Abstract:
This work is split into three parts: 1) the systematics of a bee's group, 2) the current condition of the bee’s fauna of a selected area and 3) causes for the decline of two species.

Part 1:
Efficient species conservation is only possible if large-scaled, sound taxonomic information is available. Several species of the subgenus Chalicodoma have been described from Europe and North Africa, but a sound taxonomic revision is missing. In this study 30 males from 19 described species are compared through the study of sternites 4-6. Dissection and drawings allowed the comparison of these characteristics. The traits on sternites 4-6 were found to be highly variable between, but constant within species. Some described species, however, did not show any difference and are therefore considered to be identical. The results suggest that Megachile (Chalicodoma) albonotata and M. rufescens are identical, M. branick and M. nasidens and M. judea, M. benoisti and M. apennina and M. pyrenaica, M. incerta and M. jeanneli. A determination key for males of Chalicodoma in Europe based on these traits is proposed.

Part 2:
Considering the disappearance of sandy river meadows from the Rhone (Valais) many plants and animals which are adapted to this environment have become rare. The Leukerfeld is one of the last half-natural areas of this type. On the ecological compensation surface from the highway A9, as well as on the golf course Leuk, a list of the wild bees’ species was made within the framework of this study between March and September 2011. Using a net, 106 species were registered, 44 stand on the official red list of the endangered species of Switzerland. Among other species we found the extremely rare Melitturga claviventris, Collectes fodiens and Lasioglossum quadrinotatulum. Keeping sandy ground, adapted mowing and careful watering are recommended as conservative measures.

Part 3:
Among all factors that supposedly underlie the present decline in bee diversity, habitat loss is thought to be the most significant threat. Solitary bees require enormous quantities of pollen to provision their brood cells. Both pollen requirement and reaction to habitat loss vary between bee species. In this study, the situation of two critically endangered species of Switzerland was analysed, focusing on the pollen offer in their habitat. Population size was estimated using mark-recapture methods. The pollen budget was calculated for the plant population at each site and the pollen requirement of each species was compared to the total pollen offer. The size of the population of Andrena potentillae appears to be limited by the pollen provided by their host plant. In contrast, the population size of Anthidium interruptum was much lower than the population size theoretically possible, given the pollen budget. The population is probably limited either by a sum of different factors resulting in a natural annual fluctuation in population size or by competition with Apis mellifera. The second explanation should be pursued in future studies as it concerns not only A. interruptum but pollinating insects in general.

Leading questions:
  • Do male sternites provide taxonomic information on bees’ species in Europe and the Middle East?

  • How diversify are wild bees’ species on the Leukerfeld?

  • On which degree are available pollen resources a limiting factor on bee population size?

    Publications:
    Gerber Sonja, 2011. Between Theory and Praxis: Conservation of Solitary Bees. Master Thesis, University Neuchâtel


    Last update: 12/29/16
    Source of data: ProClim- Research InfoSystem (1993-2024)
    Update the data of project: CH-4949

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