Factors affecting the occurrence of the
endangered saproxylic beetle Osmoderma eremita (Scopoli, 1763)
(Coleoptera: Cetoniidae) in an agricultural landscape
Glenn F. Duboisa,
,
,
Vincent Vignonb,
,
Yannick R. Delettrec,
,
Yann Rantierc,
,
Philippe Vernona,
and Françoise Burelc,

aUMR 6553, Université de Rennes 1, CNRS,
Station Biologique de Paimpont, 35380 Paimpont, France
bOGE – Office de Génie Écologique, 5 Bd
de Créteil, 94100 Saint-Maur-des-Fossés, France
cUMR 6553, Université de Rennes 1, CNRS,
Avenue du Général Leclerc, CS 74205, 35042 Rennes cedex, France
Abstract
Agricultural landscapes structured by trees are substitution
habitats for some species that inhabited mature trees of primeval forest.
Those agricultural landscapes have a complex heterogeneous structure that
changes over centuries. These dynamics could affect the persistence of such
relict species. We studied factors affecting the occurrence of the endangered
habitat-tracking beetle Osmoderma eremita in a landscape structured by
hedgerows and orchards. By surveying the mature trees in 2003 and the change
of landscape features between 1947 and 2003 in a 16-km2 area in
northwestern France, we tested several hypotheses. The first hypothesis was
that the occupancy rate of microhabitat would be affected by tree species. The
second was that landscape openness and microhabitat density would influence
the occurrence of O. eremita. Third, the spatio-temporal change of
landscape features after land consolidation was tested as a predictor of O.
eremita presence. We showed that O. eremita preferred apple trees
of orchards and pollard oaks of hedgerows in the most open parts of the
landscape. Short range microhabitat density and aggregation of populations
were significantly highest in orchards. Populations subsisted in areas where
few changes occurred with time in hedgerow density, revealing the sensitivity
of this habitat-tracking species to landscape changes in a complex human made
landscape. All these results should be considered for conservation planning of
this endangered species.
Keywords: Conservation; Habitat-tracking
species; Landscape openness; Mature tree; Microhabitat density; Multiscale
analysis