The saproxylic beetle Bolitophagus reticulatus: its frequency in managed forests, attraction to volatiles and flight period

• Published in: Ecography (Copenhagen) 2003-08, Vol.26 (4), p.421-428
• Main Authors: Jonsell, Mats, Schroeder, Martin, Larsson, Therese
• Format: Article
• Language: English
• Subjects: Ambrosia beetles; Animal, plant and microbial ecology; Applied ecology; Bark beetles; Beetles; Biological and medical sciences; Boreal forests; Colonization; Conservation, protection and management of environment and wildlife; Dead wood; Ethanol; Forest stands; Fruiting bodies; Fundamental and applied biological sciences. Psychology; Odors; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking
• ISSN: 0906-7590; 1600-0587
• DOI: 10.1034/j.1600-0587.2003.03449.x

Reduction in amount of dead trees in Scandinavian forests due to intensive forest management has aroused interest in the requirements of saproxylic (wood-living) species. Much attention has been focused on Bolitophagus reticulatus, a tenebrionid beetle that lives on polypore fruiting bodies of Fomes fomentarius. Although earlier studies have suggested that the species has limited dispersal abilities, the beetle is abundant and widely distributed in Swedish forests. To resolve this paradox we conducted a series of field experiments. Firstly, the frequency of the species was found to be similar in six forest stands with a low density of fruiting bodies and six stands with a high density. Secondly, flying individuals were caught in window traps placed in all of eight randomly chosen, well-managed pine stands. Thirdly, we tested volatiles that flying beetles may use to find hosts by baiting window traps. We found strong attractions to ethanol and to a combination of ethanol and fruiting body. The dispersal period was almost entirely restricted to one week during the summer. Our results suggest that B. reticulatus is distributed wherever the host occurs. Long distance dispersal of B. reticulatus is difficult to observe, but appears to be effective when it does occur. Previously observed patchy distribution patterns of the species are probably due to short-distance movements being more frequent than long-distance movements. A general conclusion is that interpretations based on mark-recapture data and indirect measures of substrate and beetle occurrences that claims limited dispersal should be treated with caution.