02927nas a2200337   4500008004100000245016300041210006900204260000800273300001200281490000700293520190100300653002002201653001602221653002702237653002702264653002802291653001702319653000802336653003002344653001202374653002702386653001702413653002202430653000902452653001502461100002102476700001802497700002002515700002002535856003402555       2000                        eng d00aA comparative analysis of metabolic rate in six Scarabaeus species (Coleoptera : Scarabaeidae) from southern Africa: further caveats when inferring adaptation0 acomparative analysis of metabolic rate in six Scarabaeus species  cApr  a553-5620 v463 aAlterations 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<S. hippocrates<S. striatum<S. galenus<S. rusticus<S. westwoodi. General Linear models were fitted to the VCO2 data with treatment temperature, wing status, mean annual rainfall and mean annual temperature as the independent variables. For all six species, the best fit model included treatment temperature and wing status only. Flightless species had significantly lower VCO(2)s than did winged ones. Amongst the flightless species, S. gariepinus, from the driest area, had the lowest VCO2. Among the winged species it was impossible to determine whether environmental temperature or water availability were most important in influencing VCO2; both were significant. We conclude that investigations of metabolic rate modulation, and especially metabolic cold adaptation, in insects must take both temperature and water availability into account. (C) 2000 Elsevier Science Ltd. All rights reserved.10aacclimatisation10aconsumption10acricket gryllus-firmus10adesiccation resistance10adrosophila-melanogaster10agas-exchange10ains10ametabolic cold adaptation10aoxygen-10arespiratory metabolism10arespirometry10aunselected strain10aVCO210awater-loss1 aDavis, A., L. V.1 aChown, S., L.1 aMcGeoch, M., A.1 aScholtz, C., H.  u<Go to ISI>://00008584250001902417nas a2200301   4500008004100000245006700041210006400108300001000172490000700182520151100189653002301700653001501723653001601738653002801754653002601782653002701808653002701835653002301862653001301885653001801898653002201916653002401938653001301962100001301975700002001988700002002008856008702028       2002                        eng d00aA cost of maternal care in the dung beetle Onthophagus taurus?0 acost of maternal care in the dung beetle Onthophagus taurus  a57-640 v153 aParental care theory assumes that investment in current offspring will trade against future investment. A number of field studies on birds have used clutch size manipulations to demonstrate a survival cost to chick rearing. However, such studies do not account for costs accrued during earlier stages of reproduction because not all aspects of reproductive effort are manipulated by varying the number of nestlings. in this study, we investigate the effect of reproductive effort on female survival in the dung beetle, Onthophagus taurus. By experimentally manipulating mating status and dung availability, we demonstrate that virgin females survive longer than mated females and that the survival of mated females was negatively associated with the number of brood masses produced. Using a novel manipulation of the mating system, we separated the effects of egg production and maternal care on female survival. Previously, we have shown that females provisioning with the assistance of a major male provide relatively less care than unassisted females. However, paternal assistance did not alter the number of brood masses produced and hence the amount of reproductive effort that was allocated to egg production. Therefore, our finding, that female survival was increased when receiving paternal assistance provides, to our knowledge, the first definitive evidence that maternal care reduces female lifespan. These results are of major importance to theoretical models on the evolution of parental care.10aBREEDING BLUE TITS10aBROOD-SIZE10aCLUTCH-SIZE10adrosophila-melanogaster10afluctuating asymmetry10aLIFE-HISTORY EVOLUTION10alife-history trade-off10aOnthophagus taurus10aPARENTAL10aParental care10areproductive cost10areproductive effort10aSURVIVAL1 aHunt, J.1 aSimmons, L., W.1 aKotiaho, J., S.  uhttps://scarabnet.myspecies.info/cost-maternal-care-dung-beetle-onthophagus-taurus01969nas a2200289   4500008004100000245006400041210006300105260000800168300001200176490000700188520117500195653001501370653001901385653002901404653001101433653002801444653002501472653001601497653001001513653001901523653002601542653002401568653001601592100001901608700001801627856003401645       1999                        eng d00aElevation and climatic tolerance: a test using dung beetles0 aElevation and climatic tolerance a test using dung beetles  cSep  a584-5900 v863 aAn increase in the altitudinal range of occurrence of species in an assemblage with increasing elevation has been explained as a consequence of individual organisms having to be able to withstand a broader range of climatic conditions at higher elevations; the climatic variability hypothesis. Here we show that for scarab dung beetles (26 species) across an elevational transect (approx. 2500 In) in southern Africa thermal tolerance range does increase with increasing elevation across individuals and across species. The maximal thermal tolerance range exhibited increases slowly with elevation and the minimum range increases more rapidly. The mechanistic basis of the change appears to be one of rapidly changing critical thermal minimum (CTmin) with elevation and only small changes in critical thermal maximum (CTmax). Of course, even if the pattern of tolerance of species assumed by the climatic variability hypothesis is correct, an increase in altitudinal range with increasing elevation need not necessarily follow. However, although sampling has been limited, there does appear to be an elevational increase in altitudinal range for this species assemblage.10aarthropods10acold-hardiness10acritical thermal maximum10adesert10adrosophila-melanogaster10alatitudinal gradient10alepidoptera10anamib10arapoports rule10atemperature tolerance10atenebrionid beetles10aterrestrial1 aGaston, K., J.1 aChown, S., L.  u<Go to ISI>://000082248200019