About this Journal Submit a Manuscript Table of Contents
Psyche
Volume 2010 (2010), Article ID 707501, 13 pages
http://dx.doi.org/10.1155/2010/707501
Research Article

Trade-Off between Foraging Activity and Infestation by Nest Parasites in the Primitively Eusocial Bee Halictus scabiosae

1Institute of Zoology, University Graz, 8010 Graz, Austria
2Seed Conservation Department, Royal Botanic Gardens, Kew, Wakehurst Place, West Sussex RH17 6TN, UK

Received 10 August 2009; Accepted 12 November 2009

Academic Editor: James C. Nieh

Copyright © 2010 Andrea Lienhard et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Diurnal activities of Halictus scabiosae bees and their nest parasites (major bee-flies, cuckoo wasps, ichneumon wasps, Sphecodes bees, and velvet ants) were investigated at a study site with 159 nests in Eastern Austria. Foraging activity correlated with ambient temperature only before midday and decreased in the afternoon. The activity of nest-infesting parasites increased during the day and correlated with ambient temperature. The match factor fm between the ratios of the foraging activities of H. scabiosae and the ratios of aspects of morning temperature was assessed on three consecutive days with different weather. The activity patterns of halictine bees and their nest parasites differed: the parasites exhibited only small time windows in which their activities were synchronised with those of their hosts. The bees exhibited an anticyclic behaviour and collected food in times of low parasite pressure and decreased foraging activity when parasite pressure increased.