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Dispersal Ecology of Insects Inhabiting Wood-Decaying Fungi

Jonsson, Mattias (2002). Dispersal Ecology of Insects Inhabiting Wood-Decaying Fungi. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae. Silvestria, 1401-6230 ; 241
ISBN 91-576-6325-4
[Doctoral thesis]

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Abstract

Abstract Distribution patterns of several threatened wood-living insects indicate that they are poor dispersers, but few studies have directly investigated their dispersal ability. Therefore, I have studied key aspects of the dispersal ecology of wood-living insects, focusing on beetles inhabiting fruiting bodies of the wood-decaying fungi Fomes fometarius and Fomitopsis pinicola. The genetic structures of the threatened tenebrionid beetle Oplocephala haemorrhoidalis and its common relative Bolitophagus reticulatus were studied using RAPD and allozyme genetic markers. We found higher levels of genetic differentiation in O. haemorrhoidalis than in B. reticulatus, suggesting that levels of gene flow between populations are lower in the former species, but the level of genetic variability was not particularly low in either of them. The colonisation abilities of O. haemorrhoidalis and B. reticulatus were studied by comparing a number of life history traits in the two species. Bolitophagus reticulatus was found to have a higher proportion of individuals with developed flight muscles than O. haemorrhoidalis, a greater willingness to take-off, and its females had more (but smaller) eggs in their abdomens. Oplocephala haemorrhoidalis tended to make few flights of long duration, whereas B. reticulatus made shorter but more numerous flights. However, both species were able to cover several kilometres in flight. I suggest that B. reticulatus possesses a suite of life history traits that make it better adapted than O. haemorrhoidalis to exploit the scattered trees with fruiting bodies present in managed forests. To succeed with colonisation, insects that disperse before mating must find mates at their new habitats. In a field experiment, we studied whether representatives of the beetle genera Cis (Cisidae) and Dorcatoma (Anobiidae) utilise long-range pheromones to locate mates. Two strategies for finding mates were identified. In Cis both sexes were attracted by the odour of their host fungus, but in Dorcatoma only females were attracted by host odour while males were attracted by a sexual pheromone released by the female. The efficiency of the two mate-finding strategies was compared with a simulation model. Very small differences in effectiveness between the strategies were found at high relative densities of insects. However, the pheromone strategy (used by Dorcatoma) became relatively more efficient when the relative density of insects and the density of substrate decreased. Thus, species using the non-pheromone strategy of mate-finding (like Cisidae) are probably more sensitive to habitat fragmentation and are likely to experience Allee effects at higher population densities.

Authors/Creators:Jonsson, Mattias
Title:Dispersal Ecology of Insects Inhabiting Wood-Decaying Fungi
Year of publishing :January 2002
Volume:241
Number of Pages:27
Papers/manuscripts:
NumberReferences
ALLThis thesis is based on the following papers, which will be referred to in the text by the respective Roman numerals. I. Jonsson, M., Johannesen, J. & Seitz, A. Comparative genetic structure of the threatened tenebrionid beetle Oplocephala haemorrhoidalis and its common relative Bolitophagus reticulatus. Submitted manuscript. II. Jonsson, M. Colonisation ability of the threatened tenebrionid beetle Oplocephala haemorrhoidalis and its common relative Bolitophagus reticulatus. Manuscript. III. Jonsson, M., Nordlander, G. & Jonsell M. 1997. Pheromones affecting flying beetles colonizing the polypores Fomes fomentarius and Fomitopsis pinicola. Entomologica Fennica, 8, 161-165. IV. Jonsson, M., Kindvall, O., Jonsell, M. & Nordlander, G. Modelling mating success of saproxylic beetles in relation to search behaviour, population density and substrate abundance. Manuscript. Paper III is reproduced with the kind permission of the publisher.
Place of Publication:Uppsala
ISBN for printed version:91-576-6325-4
ISSN:1401-6230
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L20 Animal ecology
Subjects:Not in use, please see Agris categories
Agrovoc terms:coleoptera, animal ecology, population ecology, colonizing ability, fungi, gene flow, genetic markers, life cycle, pheromones
Keywords:Colonisation, conservation, dispersal, gene flow, genetic structure, life history, pheromone, saproxylic beetles, tethered flight
ID Code:64
Department:?? 5040 ??
Deposited By: Mattias Jonsson
Deposited On:15 Aug 2002 00:00
Metadata Last Modified:02 Dec 2014 10:01

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