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The long summer: pre-wintering temperatures affect metabolic expenditure and winter survival in a solitary bee.

The long summer: pre-wintering temperatures affect metabolic expenditure and winter survival in a solitary bee.

Authors :
Sgolastra F
Kemp WP
Buckner JS
Pitts-Singer TL
Maini S
Bosch J
Source :
Journal of insect physiology [J Insect Physiol] 2011 Dec; Vol. 57 (12), pp. 1651-9. Date of Electronic Publication: 2011 Sep 01.
Publication Year :
2011

Abstract

The impact of climate change on insect populations depends on specific life cycle traits and physiological adaptations. The solitary bee Osmia lignaria winters as a pre-emergent adult, and requires a period of cold temperature for winter diapause completion. It is a univoltine species, and diapause induction does not depend on photoperiod. To understand the potential effects of longer summers on O. lignaria populations, we exposed individuals to three treatments simulating early, mid and late winter arrivals, and measured respiration rates, metabolic expenditure, weight loss, fat body depletion, lipid levels and winter mortality. The early-winter treatment disrupted diapause development, but had no apparent negative effects on fitness. In contrast, late-winter bees had a greater energetic expenditure (1.5-fold), weight (1.4-fold) and lipid (2-fold) loss, greater fat body depletion, and a 19% increase in mortality compared to mid-winter bees. We also monitored adult eclosion and arrival of winter temperatures under natural conditions in four years. We found a positive correlation between mean degree-day accumulation during pre-wintering (a measure of asynchrony between adult eclosion and winter arrival) and yearly winter mortality. Individually, bees experiencing greater degree-day accumulations exhibited reduced post-winter longevity. Timing of adult eclosion in O. lignaria is dependent on the duration of the prepupal period, which occurs in mid-summer, is also diapause-mediated, and is longer in populations from southerly latitudes. In a global warming scenario, we expect long summer diapause phenotypes to replace short summer diapause phenotypes, effectively maintaining short pre-wintering periods in spite of delayed winter arrivals.<br /> (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Details

Language :
English
ISSN :
1879-1611
Volume :
57
Issue :
12
Database :
MEDLINE
Journal :
Journal of insect physiology
Publication Type :
Academic Journal
Accession number :
21910996
Full Text :
https://doi.org/10.1016/j.jinsphys.2011.08.017