Do insect metabolic rates at rest and during flight scale with body mass?

Abstract

Energetically costly behaviours, such as flight, push physiological systems to their limits requiring metabolic rates (MR) that are highly elevated above the resting MR (RMR). Both RMR and MR during exercise (e.g. flight or running) in birds and mammals scale allometrically, although there is little consensus about the underlying mechanisms or the scaling relationships themselves. Even less is known about the allometric scaling of RMR and MR during exercise in insects. We analysed data on the resting and flight MR (FMR) of over 50 insect species that fly to determine whether RMR and FMR scale allometrically. RMR scaled with body mass to the power of 0.66 (M 0.66 ), whereas FMR scaled with M 1.10 . Further analysis suggested that FMR scaled with two separate relationships; insects weighing less than 10 mg had fourfold lower FMR than predicted from the scaling of FMR in insects weighing more than 10 mg, although both groups scaled with M 0.86 . The scaling exponents of RMR and FMR in insects were not significantly different from those of birds and mammals, suggesting that they might be determined by similar factors. We argue that low FMR in small insects suggests these insects may be making considerable energy savings during flight, which could be extremely important for the physiology and evolution of insect flight.

Effects of metabolic level on the body size scaling of metabolic rate in birds and mammals

“…This and other evidence provided by Glazier (2005), Makarieva et al (2005a), Niven & Scharlemann (2005), Reich et al (2006) and White et al (2006White et al ( , 2007 strongly support the MLB hypothesis, but is inconsistent with the 3/4-power law and models proposed to explain it. In fact, of the 37 b values in table 1 with calculated 95% confidence limits, 78% (29) are significantly different from 3/4.…”

“…First, several rigorous empirical analyses, involving body sizes spanning several orders of magnitude, have shown that b often deviates substantially from 3/4, varying significantly among different taxonomic groups of animals and plants (Glazier 2005;Reich et al 2006;White et al 2006White et al , 2007, and among different physiological states (Glazier 2005;Niven & Scharlemann 2005;White & Seymour 2005;Makarieva et al 2005aMakarieva et al , 2006b). Second, the models supporting the so-called 3/4-power law appear to have flawed assumptions and serious mathematical inconsistencies that have not yet been resolved, despite much debate (Dodds et al 2001;Kozlowski & Konarzewski 2004, 2005Brown et al 2005;Makarieva et al 2005bMakarieva et al , 2006aPainter 2005b,c;Banavar et al 2006;Chaui-Berlinck 2006, 2007Etienne et al 2006;Savage et al 2007).…”

Haematophagy is costly: respiratory patterns and metabolism during feeding inRhodnius prolixus

“…The increase associated with taking a blood meal is up to three times over that of walking in the ant Camponotus sp. (Lipp et al, 2005) and even higher than the metabolic increase of flying over resting in terms of mass-specific rate of O 2 consumption for Drosophila melanogaster (Hocking, 1953;Lehmann et al, 2000;Niven and Scharlemann, 2005). It is, however, lower than the increase in oxygen consumption associated with flying in the bee Apis mellifera and the grasshopper Schistocerca gregaria (Niven and Scharlemann, 2005), and lower as well to the increase in metabolic rate during leaf-cutting in the ant Atta sexdens rubropilosa (Roces and Lighton, 1995).…”

Genotype by temperature interactions in the metabolic rate of the Glanville fritillary butterfly

“…Flight capacity may also have indirect consequences in the form of trade-offs with other energy-demanding processes such as reproduction (Nespolo et al, 2008;Saglam et al, 2008). The need for a high flight capacity may be reflected in the cost of maintenance, namely in the resting metabolic rate, but while a positive relationship between maximum and minimum metabolic rates is well established for vertebrates (Bennett and Ruben, 1979;Dutenhoffer and Swanson, 1996;Hinds et al, 1993;Walton, 1993;White and Seymour, 2004), it is less clear what this relationship is in invertebrates and in insects in particular (Niven and Scharlemann, 2005;Reinhold, 1999).…”