A comparative analysis of metabolic rate in six Scarabaeus species (Coleoptera : Scarabaeidae) from southern Africa: further caveats when inferring adaptation

Publication Type:Journal Article
Year of Publication:2000
Authors:A. L. V. Davis, Chown, S. L., McGeoch, M. A., Scholtz, C. H.
Journal:Journal of Insect Physiology
Date Published:Apr
Accession Number:ISI:000085842500019
Keywords:acclimatisation, consumption, cricket gryllus-firmus, desiccation resistance, drosophila-melanogaster, gas-exchange, ins, metabolic cold adaptation, oxygen-, respiratory metabolism, respirometry, unselected strain, VCO2, water-loss

Alterations in VO2 or VCO2 are amongst the more polemical physiological adaptations ascribed to insects. Generally, metabolic rate is thought to be lowered in response to arid conditions, and elevated in species from cold environments compared to their more temperate relatives. However, most studies have rarely addressed the influence of both environmental factors in unison. To this end, standard metabolic rate and its temperature dependence were measured (at 4 degrees C intervals from 16 to 32 degrees C) in six Scarabaeus dung beetle species (three flightless, three volant) from a variety of habitats (warm, arid to cool, mesic) in southern Africa using flow-through respirometry. Mass specific VCO2 varied from 0.0158 mi g(-1) h(-1) at 16 degrees C to 0.1839 ml g(-1) h(-1) at 32 degrees C. The slopes of the rate temperature curves were similar for all species (Q(10)s of 2.14-2.84), although the intercepts differed significantly in the direction (warm arid to cool mesic): S. gariepinus

URL:<Go to ISI>://000085842500019
Alternate Journal:J. Insect Physiol.
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