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Water Costs of Gas Exchange by a Speckled Cockroach and a Darkling Beetle. INSECTS 2020; 11:insects11090632. [PMID: 32937981 PMCID: PMC7563770 DOI: 10.3390/insects11090632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/26/2020] [Accepted: 09/10/2020] [Indexed: 11/16/2022]
Abstract
Simple Summary Evaporative water loss during metabolic gas exchange is an unavoidable cost of living for terrestrial insects. This respiratory water cost of gas exchange (the ratio of respiratory water loss to metabolic rate) is suggested to depend on several factors, such as the mode of gas exchange (convection vs. diffusion), species habitat, body size and measurement conditions. We measured this cost for a blaberid cockroach and a tenebrionid beetle using flow-through respirometry. We controlled the factors that affect respiratory water cost of gas exchange, i.e., both species are similar in their mode of gas exchange (dominantly convective), habitat (relatively moist) and body size, and were measured at the same temperature. The cockroaches showed both continuous and discontinuous gas exchange patterns, which had a significantly different metabolic rate and respiratory water loss but the same respiratory water cost of gas exchange. The darkling beetles showed a continuous gas exchange pattern only, and their metabolic rate, respiratory water loss and respiratory water cost of gas exchange were equivalent to those cockroaches using continuous gas exchange. This finding from our study highlights that the respiratory water cost of gas exchange is similar between species, regardless of the gas exchange pattern used, when the confounding factors affecting this cost are controlled. However, the total evaporative water cost of gas exchange is much higher than the respiratory cost because cuticular water loss contributes considerably more to the overall evaporative water loss than respiratory water. We suggest that the total water cost of gas exchange is likely to be a more useful indicator of species distribution with respect to environmental aridity than just the respiratory water cost. Abstract Respiratory water loss during metabolic gas exchange is an unavoidable cost of living for terrestrial insects. It has been suggested to depend on several factors, such as the mode of gas exchange (convective vs. diffusive), species habitat (aridity), body size and measurement conditions (temperature). We measured this cost in terms of respiratory water loss relative to metabolic rate (respiratory water cost of gas exchange; RWL/V˙CO2) for adults of two insect species, the speckled cockroach (Nauphoeta cinerea) and the darkling beetle (Zophobas morio), which are similar in their mode of gas exchange (dominantly convective), habitat (mesic), body size and measurement conditions, by measuring gas exchange patterns using flow-through respirometry. The speckled cockroaches showed both continuous and discontinuous gas exchange patterns, which had significantly a different metabolic rate and respiratory water loss but the same respiratory water cost of gas exchange. The darkling beetles showed continuous gas exchange pattern only, and their metabolic rate, respiratory water loss and respiratory cost of gas exchange were equivalent to those cockroaches using continuous gas exchange. This outcome from our study highlights that the respiratory water cost of gas exchange is similar between species, regardless of gas exchange pattern used, when the confounding factors affecting this cost are controlled. However, the total evaporative water cost of gas exchange is much higher than the respiratory cost because cuticular water loss contributes considerably more to the overall evaporative water loss than respiratory water. We suggest that the total water cost of gas exchange is likely to be a more useful index of environmental adaptation (e.g., aridity) than just the respiratory water cost.
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Réveillon T, Rota T, Chauvet É, Lecerf A, Sentis A. Repeatable inter‐individual variation in the thermal sensitivity of metabolic rate. OIKOS 2019. [DOI: 10.1111/oik.06392] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Tom Réveillon
- EcoLab, Univ. de Toulouse, CNRS, INP, UPS Toulouse France
| | - Thibaut Rota
- EcoLab, Univ. de Toulouse, CNRS, INP, UPS Toulouse France
| | - Éric Chauvet
- EcoLab, Univ. de Toulouse, CNRS, INP, UPS Toulouse France
| | - Antoine Lecerf
- EcoLab, Univ. de Toulouse, CNRS, INP, UPS Toulouse France
| | - Arnaud Sentis
- IRSTEA, Aix Marseille Univ., UMR RECOVER, 3275 route Cézanne FR‐13182 Aix‐en‐Provence France
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Doubell M, Grant PBC, Esterhuizen N, Bazelet CS, Addison P, Terblanche JS. The metabolic costs of sexual signalling in the chirping katydid Plangia graminea (Serville) (Orthoptera: Tettigoniidae) are context dependent: cumulative costs add up fast. ACTA ACUST UNITED AC 2017; 220:4440-4449. [PMID: 28970347 DOI: 10.1242/jeb.160036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 09/26/2017] [Indexed: 11/20/2022]
Abstract
Katydids produce acoustic signals via stridulation, which they use to attract conspecific females for mating. However, direct estimates of the metabolic costs of calling to date have produced diverse cost estimates and are limited to only a handful of insect species. Therefore, in this study, we investigated the metabolic cost of calling in an unstudied sub-Saharan katydid, Plangia graminea Using wild-caught animals, we measured katydid metabolic rate using standard flow-through respirometry while simultaneously recording the number of calls produced. Overall, the metabolic rate during calling in P. graminea males was 60% higher than the resting metabolic rate (0.443±0.056 versus 0.279±0.028 ml CO2 h-1 g-1), although this was highly variable among individuals. Although individual call costs were relatively inexpensive (ranging from 0.02 to 5.4% increase in metabolic rate per call), the individuals with cheaper calls called more often and for longer than those with expensive calls, resulting in the former group having significantly greater cumulative costs over a standard amount of time (9.5 h). However, the metabolic costs of calling are context dependent because the amount of time spent calling greatly influenced these costs in our trials. A power law function described this relationship between cumulative cost (y) and percentage increase per call (x) (y=130.21x-1.068, R2=0.858). The choice of metric employed for estimating energy costs (i.e. how costs are expressed) also affects the outcome and any interpretation of costs of sexual signalling. For example, the absolute, relative and cumulative metabolic costs of calling yielded strongly divergent estimates, and any fitness implications depend on the organism's energy budget and the potential trade-offs in allocation of resources that are made as a direct consequence of increased calling effort.
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Affiliation(s)
- Marcé Doubell
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa
| | - Paul B C Grant
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa.,Grant Scientific Services Ltd, 4901 Cherry Tree Bend, Victoria BC V8Y1S1, Canada
| | - Nanike Esterhuizen
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa.,Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa
| | - Corinna S Bazelet
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa
| | - Pia Addison
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa
| | - John S Terblanche
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, Stellenbosch, South Africa
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Gienger C, Urdiales EM. Influences on Standard Metabolism in Eastern Box Turtles (Terrapene carolina). CHELONIAN CONSERVATION AND BIOLOGY 2017. [DOI: 10.2744/ccb-1252.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- C.M. Gienger
- Department of Biology and Center of Excellence for Field Biology, Austin Peay State University, Clarksville, Tennessee 37044 USA []
| | - Eva M. Urdiales
- Department of Biology and Center of Excellence for Field Biology, Austin Peay State University, Clarksville, Tennessee 37044 USA []
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5
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The mechanisms underlying the production of discontinuous gas exchange cycles in insects. J Comp Physiol B 2017; 188:195-210. [DOI: 10.1007/s00360-017-1121-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 07/27/2017] [Accepted: 08/06/2017] [Indexed: 10/19/2022]
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Harrison JF, Manoucheh M, Klok CJ, Campbell JB. Temperature and the Ventilatory Response to Hypoxia in Gromphadorhina portentosa (Blattodea: Blaberidae). ENVIRONMENTAL ENTOMOLOGY 2016; 45:479-483. [PMID: 26721296 DOI: 10.1093/ee/nvv217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 12/03/2015] [Indexed: 06/05/2023]
Abstract
In general, insects respond to hypoxia by increasing ventilation frequency, as seen in most other animals. Higher body temperatures usually also increase ventilation rates, likely due to increases in metabolic rates. In ectothermic air-breathing vertebrates, body temperatures and hypoxia tend to interact significantly, with an increasing responsiveness of ventilation to hypoxia at higher temperatures. Here, we tested whether the same is true in insects, using the Madagascar hissing cockroach, Gromphadorhina portentosa (Schaum) (Blattodea: Blaberidae). We equilibrated individuals to a temperature (beginning at 20 °C), and animals were exposed to step-wise decreases in PO2 (21, 15, 10, and 5 kPa, in that order), and we measured ventilation frequencies from videotapes of abdominal pumping after 15 min of exposure to the test oxygen level. We then raised the temperature by 5 °C, and the protocol was repeated, with tests run at 20, 25, 30, and 35 °C. The 20 °C animals had high initial ventilation rates, possibly due to handling stress, so these animals were excluded from subsequent analyses. Across all temperatures, ventilation increased in hypoxia, but only significantly at 5 kPa PO2 Surprisingly, there was no significant interaction between temperature and oxygen, and no significant effect of temperature on ventilation frequency from 25 to 35 °C. Plausibly, the rise in metabolic rates at higher temperatures in insects is made possible by increasing other aspects of gas exchange, such as decreasing internal PO2, or increases in tidal volume, spiracular opening (duration or amount), or removal of fluid from the tracheoles.
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Affiliation(s)
- Jon F Harrison
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501 (; ; ; ) and
| | - Milad Manoucheh
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501 (; ; ; ) and
| | - C Jaco Klok
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501 (; ; ; ) and
| | - Jacob B Campbell
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501 (; ; ; ) and
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Gudowska A, Drobniak SM, Schramm BW, Labecka AM, Kozlowski J, Bauchinger U. Hold your breath beetle-Mites! Evolution 2015; 70:249-55. [DOI: 10.1111/evo.12827] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 11/06/2015] [Accepted: 11/11/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Agnieszka Gudowska
- Institute of Environmental Sciences; Jagiellonian University; ul. Gronostajowa 7 30-387 Kraków Poland
| | - Szymon M. Drobniak
- Institute of Environmental Sciences; Jagiellonian University; ul. Gronostajowa 7 30-387 Kraków Poland
| | - Bartosz W. Schramm
- Institute of Environmental Sciences; Jagiellonian University; ul. Gronostajowa 7 30-387 Kraków Poland
| | - Anna Maria Labecka
- Institute of Environmental Sciences; Jagiellonian University; ul. Gronostajowa 7 30-387 Kraków Poland
| | - Jan Kozlowski
- Institute of Environmental Sciences; Jagiellonian University; ul. Gronostajowa 7 30-387 Kraków Poland
| | - Ulf Bauchinger
- Institute of Environmental Sciences; Jagiellonian University; ul. Gronostajowa 7 30-387 Kraków Poland
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Gonzales Correa YDC, Faroni LRA, Haddi K, Oliveira EE, Pereira EJG. Locomotory and physiological responses induced by clove and cinnamon essential oils in the maize weevil Sitophilus zeamais. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2015; 125:31-37. [PMID: 26615148 DOI: 10.1016/j.pestbp.2015.06.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 06/05/2023]
Abstract
Plant essential oils have been suggested as a suitable alternative for controlling stored pests worldwide. However, very little is known about the physiological or behavioral responses induced by these compounds in insect populations that are resistant to traditional insecticides. Thus, this investigation evaluated the toxicity (including the impacts on population growth) as well as the locomotory and respiratory responses induced by clove, Syzygium aromaticum L., and cinnamon, Cinnamomum zeylanicum L., essential oils in Brazilian populations of the maize weevil Sitophilus zeamais. We used populations that are resistant to phosphine and pyrethroids (PyPhR), only resistant to pyrethroids (PyR1 and PyR2) or susceptible to both insecticide types (SUS). The PyPhR population was more tolerant to cinnamon essential oil, and its population growth rate was less affected by both oil types. Insects from this population reduced their respiratory rates (i.e., CO2 production) after being exposed to both oil types and avoided (in free choice-experiments) or reduced their mobility on essential oil-treated surfaces. The PyR1 and PyR2 populations reduced their respiratory rates, avoided (without changing their locomotory behavior in no-choice experiments) essential oil-treated surfaces and their population growth rates were severely affected by both oil types. Individuals from SUS population increased their mobility on surfaces that were treated with both oil types and showed the highest levels of susceptibility to these oils. Our findings indicate that S. zeamais populations that are resistant to traditional insecticides might have distinct but possibly overlapping mechanisms to mitigate the actions of essential oils and traditional insecticides.
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Affiliation(s)
| | - Lêda R A Faroni
- Departamento de Engenharia Agrícola, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil.
| | - Khalid Haddi
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil; Science without Border Associate Researcher, Programa de Pós-Graduação em Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-000, Brazil
| | - Eugênio E Oliveira
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil.
| | - Eliseu José G Pereira
- Departamento de Entomologia, Universidade Federal de Viçosa, Viçosa, MG 36570-900, Brazil
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Oxygen-induced plasticity in tracheal morphology and discontinuous gas exchange cycles in cockroaches Nauphoeta cinerea. J Comp Physiol B 2014; 184:977-90. [DOI: 10.1007/s00360-014-0862-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Revised: 09/09/2014] [Accepted: 09/11/2014] [Indexed: 11/30/2022]
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10
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Careau V, Gifford ME, Biro PA. Individual (co)variation in thermal reaction norms of standard and maximal metabolic rates in wild-caught slimy salamanders. Funct Ecol 2014. [DOI: 10.1111/1365-2435.12259] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Vincent Careau
- Centre for Integrative Ecology; Deakin University; Waurn Ponds Victoria Australia
| | - Matthew E. Gifford
- Department of Biology; University of Arkansas at Little Rock; Little Rock Arkansas USA
| | - Peter A. Biro
- Centre for Integrative Ecology; Deakin University; Waurn Ponds Victoria Australia
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Schimpf NG, Matthews PGD, White CR. Discontinuous gas exchange exhibition is a heritable trait in speckled cockroaches Nauphoeta cinerea. J Evol Biol 2013; 26:1588-97. [PMID: 23662792 DOI: 10.1111/jeb.12093] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Revised: 10/01/2012] [Accepted: 11/02/2012] [Indexed: 01/13/2023]
Abstract
The regulation of insect respiratory gas exchange has long been an area of interest. In particular, the reason why insects from at least five orders exhibit patterns of gas exchange that include regular periods of spiracular closure has been the source of much controversy. Three adaptive hypotheses propose that these discontinuous gas-exchange cycles (DGCs) evolved to either limit water loss across respiratory surfaces, facilitate gas exchange in underground environments or to limit oxidative damage. It is possible that DGCs evolved independently multiple times and for different reasons, but for DGCs to be a plausible target for natural selection, they must be heritable and confer a fitness benefit. In a previous study of cockroaches Nauphoeta cinerea, we demonstrated that DGCs are repeatable and extend survival under food and water restriction. Here, we show for the first time that DGCs are heritable, suggesting that they are a plausible target for natural selection.
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Affiliation(s)
- N G Schimpf
- School of Biological Sciences, The University of Queensland, St. Lucia, Qld, Australia
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Käfer H, Kovac H, Stabentheiner A. Respiration patterns of resting wasps (Vespula sp.). JOURNAL OF INSECT PHYSIOLOGY 2013; 59:475-486. [PMID: 23399474 PMCID: PMC3616262 DOI: 10.1016/j.jinsphys.2013.01.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 01/30/2013] [Indexed: 06/01/2023]
Abstract
We investigated the respiration patterns of wasps (Vespula sp.) in their viable temperature range (2.9-42.4°C) by measuring CO2 production and locomotor and endothermic activity. Wasps showed cycles of an interburst-burst type at low ambient temperatures (Ta<5°C) or typical discontinuous gas exchange patterns with closed, flutter and open phases. At high Ta of >31°C, CO2 emission became cyclic. With rising Ta they enhanced CO2-emission primarily by an exponential increase in respiration frequency, from 2.6 mHz at 4.7°C to 74 mHz at 39.7°C. In the same range of Ta CO2 release per cycle decreased from 38.9 to 26.4 μl g(-1)cycle(-1). A comparison of wasps with other insects showed that they are among the insects with a low respiratory frequency at a given resting metabolic rate (RMR), and a relatively flat increase of respiratory frequency with RMR. CO2 emission was always accompanied by abdominal respiration movements in all open phases and in 71.4% of the flutter phases, often accompanied by body movements. Results suggest that resting wasps gain their highly efficient gas exchange to a considerable extent via the length and type of respiration movements.
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Affiliation(s)
| | - Helmut Kovac
- Corresponding authors. Tel.: +43 316 380 5705; fax: +43 316 380 9875.
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Matthews PGD, White CR. Reversible brain inactivation induces discontinuous gas exchange in cockroaches. ACTA ACUST UNITED AC 2013; 216:2012-6. [PMID: 23430991 DOI: 10.1242/jeb.077479] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Many insects at rest breathe discontinuously, alternating between brief bouts of gas exchange and extended periods of breath-holding. The association between discontinuous gas exchange cycles (DGCs) and inactivity has long been recognised, leading to speculation that DGCs lie at one end of a continuum of gas exchange patterns, from continuous to discontinuous, linked to metabolic rate (MR). However, the neural hypothesis posits that it is the downregulation of brain activity and a change in the neural control of gas exchange, rather than low MR per se, which is responsible for the emergence of DGCs during inactivity. To test this, Nauphoeta cinerea cockroaches had their brains inactivated by applying a Peltier-chilled cold probe to the head. Once brain temperature fell to 8°C, cockroaches switched from a continuous to a discontinuous breathing pattern. Re-warming the brain abolished the DGC and re-established a continuous breathing pattern. Chilling the brain did not significantly reduce the cockroaches' MR and there was no association between the gas exchange pattern displayed by the insect and its MR. This demonstrates that DGCs can arise due to a decrease in brain activity and a change in the underlying regulation of gas exchange, and are not necessarily a simple consequence of low respiratory demand.
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Affiliation(s)
- Philip G D Matthews
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland 4072, Australia.
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Groenewald B, Bazelet CS, Potter CP, Terblanche JS. Gas exchange patterns and water loss rates in the Table Mountain cockroach, Aptera fusca (Blattodea: Blaberidae). J Exp Biol 2013; 216:3844-53. [DOI: 10.1242/jeb.091199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
The importance of metabolic rate and/or spiracle modulation for saving respiratory water is contentious. One major explanation for gas exchange pattern variation in terrestrial insects is to effect a respiratory water loss (RWL) saving. To test this, we measured V·CO2 and V·H2O in a previously unstudied, mesic cockroach, Aptera fusca, and compared gas exchange and water loss parameters among the major gas exchange patterns (continuous, cyclic, discontinuous gas exchange (DGE)) at a range of temperatures. Mean V·CO2, V·H2O, and V·H2O per unit V·CO2 did not differ among the gas exchange patterns at all temperatures (p>0.09). There was no significant association between temperature and gas exchange pattern type (p=0.63). Percentage of RWL (relative to total water loss) was typically low (9.79±1.84%) and did not differ significantly among gas exchange patterns at 15°C (p=0.26). The method of estimation had a large impact on the %RWL and of three techniques investigated (traditional, regression, hyperoxic switch), the traditional method generally performed best. In many respects, A. fusca has typical gas exchange for what might be expected from other insects studied to date (e.g. V·CO2, V·H2O, RWL and CWL). However, we found for A. fusca that V·H2O expressed as a function of metabolic rate was significantly higher than the expected consensus relationship for insects, suggesting it is under considerable pressure to save water. Despite this, we found no consistent evidence supporting the conclusion that transitions in pattern type yield reductions in RWL in this mesic cockroach.
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Muljar R, Karise R, Viik E, Kuusik A, Williams I, Metspalu L, Hiiesaar K, Must A, Luik A, Mänd M. Effects of Fastac 50 EC on bumble bee Bombus terrestris L. respiration: DGE disappearance does not lead to increasing water loss. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:1469-1476. [PMID: 22960306 DOI: 10.1016/j.jinsphys.2012.08.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 08/21/2012] [Accepted: 08/27/2012] [Indexed: 06/01/2023]
Abstract
Sublethal effects of pesticides in insects can be observed through physiological changes, which are commonly estimated by metabolic rate and respiratory patterns, more precisely by the patterns of discontinuous gas-exchange (DGE) cycles. The aim of the present research was to study the effect of some low concentrations of Fastac 50 EC on the cycles of CO(2) release and respiratory water loss rates (WLR) in bumble bee Bombus terrestris L. foragers. Bumble bees were dipped into 0.004% and 0.002% Fastac 50 EC solution. Flow-through respirometry was used to record the respiration and WLR 3h before and after the treatment. The respirometry was combined with infrared actography to enable simultaneous recording of abdominal movements. Our results show that Fastac 50 EC has an after-effect on bumble bee respiratory rhythms and muscle activity but does not affect WLR. Treatment with 0.004% Fastac 50 EC solution resulted in disappearance of the respiration cycles; also the lifespan of treated bumble bees was significantly shorter. Treatment with 0.002% Fastac 50 EC solution had no significant effect on respiration patterns or longevity. We found no evidence for the DGE cycles functioning as a water saving mechanism.
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Affiliation(s)
- Riin Muljar
- Department of Plant Protection, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51014, Estonia
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Schimpf NG, Matthews PGD, White CR. Standard metabolic rate is associated with gestation duration, but not clutch size, in speckled cockroaches Nauphoeta cinerea. Biol Open 2012; 1:1185-91. [PMID: 23259052 PMCID: PMC3522879 DOI: 10.1242/bio.20122683] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 08/01/2012] [Indexed: 11/25/2022] Open
Abstract
Metabolic rate varies significantly between individuals, and these differences persist even when the wide range of biotic and abiotic factors that influence metabolism are accounted for. It is important to understand the life history implications of variation in metabolic rate, but they remain poorly characterised despite a growing body of work examining relationships between metabolism and a range of traits. In the present study we used laboratory-bred families (one sire to three dams) of Nauphoeta cinerea (Olivier) (speckled cockroaches) to examine the relationship between standard metabolic rate (SMR) and reproductive performance (number of offspring and gestation duration). We show that SMR is negatively associated with female gestation duration. Age at mating is negatively associated with gestation duration for females, and mass is negatively associated with the average gestation duration of the females a male was mated with. In addition to the results in the current literature, the results from the present study suggest that the association between metabolism and life history is more complex than simple relationships between metabolism and various fitness traits. Future work should consider longitudinal, ontogenetic as well as selective and quantitative genetic breeding approaches to fully examine the associations between metabolism and fitness.
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Affiliation(s)
- Natalie G Schimpf
- School of Biological Sciences, The University of Queensland , St Lucia 4072 , Australia
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Streicher JW, Cox CL, Birchard GF. Non-linear scaling of oxygen consumption and heart rate in a very large cockroach species (Gromphadorhina portentosa): correlated changes with body size and temperature. ACTA ACUST UNITED AC 2012; 215:1137-43. [PMID: 22399658 DOI: 10.1242/jeb.061143] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Although well documented in vertebrates, correlated changes between metabolic rate and cardiovascular function of insects have rarely been described. Using the very large cockroach species Gromphadorhina portentosa, we examined oxygen consumption and heart rate across a range of body sizes and temperatures. Metabolic rate scaled positively and heart rate negatively with body size, but neither scaled linearly. The response of these two variables to temperature was similar. This correlated response to endogenous (body mass) and exogenous (temperature) variables is likely explained by a mutual dependence on similar metabolic substrate use and/or coupled regulatory pathways. The intraspecific scaling for oxygen consumption rate showed an apparent plateauing at body masses greater than about 3 g. An examination of cuticle mass across all instars revealed isometric scaling with no evidence of an ontogenetic shift towards proportionally larger cuticles. Published oxygen consumption rates of other Blattodea species were also examined and, as in our intraspecific examination of G. portentosa, the scaling relationship was found to be non-linear with a decreasing slope at larger body masses. The decreasing slope at very large body masses in both intraspecific and interspecific comparisons may have important implications for future investigations of the relationship between oxygen transport and maximum body size in insects.
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Affiliation(s)
- Jeffrey W Streicher
- Department of Molecular and Microbiology, George Mason University, Fairfax, VA 22030, USA.
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18
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Reid D, Armstrong JD, Metcalfe NB. The performance advantage of a high resting metabolic rate in juvenile salmon is habitat dependent. J Anim Ecol 2012; 81:868-75. [DOI: 10.1111/j.1365-2656.2012.01969.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Schimpf NG, Matthews PGD, White CR. COCKROACHES THAT EXCHANGE RESPIRATORY GASES DISCONTINUOUSLY SURVIVE FOOD AND WATER RESTRICTION. Evolution 2011; 66:597-604. [DOI: 10.1111/j.1558-5646.2011.01456.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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20
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Jõgar K, Kuusik A, Ploomi A, Metspalu L, Williams I, Hiiesaar K, Kivimägi I, Mänd M, Tasa T, Luik A. Oxygen convective uptakes in gas exchange cycles in early diapause pupae of Pieris brassicae. J Exp Biol 2011; 214:2816-22. [PMID: 21832124 DOI: 10.1242/jeb.056051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Oxygen convective uptakes in gas exchange cycles were directly recorded in early diapause pupae of Pieris brassicae L. (Lepidoptera; Pieridae) by means of O2 coulometric respirometry. This method was combined with flow-through CO2 respirometry, the two systems being switchable one to the other. During recording with both systems, measurements were also taken with infrared actography. The pupae displayed short discontinuous gas exchange cycles lasting 40-70 min. No true C phase was found by flow-through measurements; instead, flutter opening of the spiracles with discrete convective O2 uptakes began shortly after the O phase whereas CO2 release was suppressed by the inward directed passive suction ventilation. The F phase was characterized by a series of small CO2 bursts (flutter events). Between these bursts, novel sub-phase `miniflutter' was observed, which consisted of six to 10 miniature inspirations without any CO2 emission. During the flow-through measurements, oxygen convective uptakes were indirectly recorded by the infrared actograph as sudden extensions (lengthening) of the abdominal segments at each spiracular microopening.
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Affiliation(s)
- Katrin Jõgar
- Estonian University of Life Sciences, Institute Agricultural and Environmental Sciences, Department of Plant Protection, Kreutzwaldi 1, Tartu 51014, Estonia.
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21
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Bushuev AV, Kerimov AB, Ivankina EV. Estimation of heritability and repeatability of resting metabolic rate in birds by the example of free-living pied flycatchers Ficedula hypoleuca (Aves: Passeriformes). ACTA ACUST UNITED AC 2011. [DOI: 10.1134/s2079086411010026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Matthews P, White C. Discontinuous Gas Exchange in Insects: Is It All in Their Heads? Am Nat 2011; 177:130-4. [DOI: 10.1086/657619] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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23
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Woods WA, Wood CAL, Ebersole J, Stevenson RD. Metabolic rate variation over adult lifetime in the butterfly Vanessa cardui (Nymphalidae: Nymphalinae): aging, feeding, and repeatability. Physiol Biochem Zool 2010; 83:858-68. [PMID: 20695812 DOI: 10.1086/656216] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Questions about the adaptive importance of metabolic rate can be approached only when measurements of differences between individuals are repeatable. We made daily measurements of CO(2) production, body mass, and food uptake over the adult life span of unmated Vanessa cardui kept under constant environmental conditions in both fed and unfed treatments. Mass and CO(2) production generally declined with age in both treatments, though with much day-to-day variability in the fed treatment. For the full samples, metabolic rate was repeatable for the unfed treatment (repeatability r = 0.60) but not for the fed treatment (r = 0.03). Differences between fed and unfed individuals of the same age range were repeatable for the unfed treatment (r = 0.39) but not for the fed treatment (r = -0.20). Removing age effects on CO(2) production yielded still higher repeatability in the unfed treatment (r = 0.83), though not in fed butterflies of the same age range (r = -0.02). However, repeatability of CO(2) production of fed butterflies increased sharply with age, rising to 0.82 for butterflies age 8-10 d. Although food uptake mass was repeatable (r = 0.52), feeding history explained little variation in CO(2) production. We conclude that for V. cardui and possibly for other insects of similar feeding habit, variation in metabolic rate between individuals is best represented by measurements of unfed individuals of the same age or of older fed individuals.
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Affiliation(s)
- William A Woods
- Department of Biology, University of Massachusetts, Boston, MA 02125-3393, USA.
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24
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Rezende EL, Tejedo M, Santos M. Estimating the adaptive potential of critical thermal limits: methodological problems and evolutionary implications. Funct Ecol 2010. [DOI: 10.1111/j.1365-2435.2010.01778.x] [Citation(s) in RCA: 190] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Enrico L. Rezende
- Departament de Genètica i de Microbiologia, Grup de Biologia Evolutiva (GBE), Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
| | - Miguel Tejedo
- Department of Evolutionary Ecology, Estación Biológica de Doñana‐CSIC, Avda. Américo Vespucio s/n, E‐41092 Sevilla, Spain
| | - Mauro Santos
- Departament de Genètica i de Microbiologia, Grup de Biologia Evolutiva (GBE), Universitat Autònoma de Barcelona, 08193 Bellaterra (Barcelona), Spain
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25
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Moerbitz C, Hetz SK. Tradeoffs between metabolic rate and spiracular conductance in discontinuous gas exchange of Samia cynthia (Lepidoptera, Saturniidae). JOURNAL OF INSECT PHYSIOLOGY 2010; 56:536-542. [PMID: 19682454 DOI: 10.1016/j.jinsphys.2009.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 08/01/2009] [Accepted: 08/03/2009] [Indexed: 05/28/2023]
Abstract
The insect tracheal system is a unique respiratory system, designed for maximum oxygen delivery at high metabolic demands, e.g. during activity and at high ambient temperatures. Therefore, large safety margins are required for tracheal and spiracular conductance. Spiracles are the entry to the tracheal system and play an important role in controlling discontinuous gas exchange (DGC) between tracheal system and atmosphere in moth pupae. We investigated the effect of modulated metabolic rate (by changing ambient temperature) and modulated spiracular conductance (by blocking all except one spiracles) on gas exchange patterns in Samia pupae. Both, spiracle blocking and metabolic rates, affected respiratory behavior in Samia cynthia pupae. While animals showed discontinuous gas exchange cycles at lower temperatures with unblocked spiracles, the respiratory patterns were cyclic at higher temperatures, with partly blocked spiracles or a combination of these two factors. The threshold for the transition from a discontinuous (DGC) to a cyclic gas exchange ((cyc)GE) was significantly higher in animals with unblocked spiracles (18.7 nmol g(-1) min(-1) vs. 7.9 nmol g(-1) min(-1)). These findings indicate an important influence of spiracle conductance on the DGC, which may occur mostly in insects showing high spiracular conductances and low metabolic rates.
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Affiliation(s)
- Christian Moerbitz
- Humboldt-Universität zu Berlin, Department of Animal Physiology, Systems Neurobiology and Neural Computation, Philippstrasse 13, 10115 Berlin, Germany
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26
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Contreras HL, Bradley TJ. Transitions in insect respiratory patterns are controlled by changes in metabolic rate. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:522-528. [PMID: 19523955 DOI: 10.1016/j.jinsphys.2009.05.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 05/20/2009] [Accepted: 05/28/2009] [Indexed: 05/27/2023]
Abstract
We examined the respiratory patterns of Rhodnius prolixus and Gromphadorhina portentosa as metabolic rates varied with temperature to determine whether insects transition from discontinuous (DGC), cyclical and continuous respiration as a response to increasing aerobic demand. Using flow through respirometry we: (1) determined the effects of temperature on metabolic rate; (2) objectively defined periods of spiracular closure; (3) observed whether there was a correlation between metabolic rate and length of spiracular closure. At low temperatures both species exhibit lengthy periods of spiracular closure reflecting a discontinuous respiratory pattern. As metabolic rate increased, periods of spiracular closure decreased and insects displayed a more cyclical pattern of respiration. As metabolic rates increased even further under the highest experimental temperatures, periods of spiracular closure decreased even more and a continuous respiratory pattern was employed by both species. Our results suggest that the three described respiratory patterns in insects are not distinct but are instead a continuum of respiratory responses driven by the metabolic demand experienced by the insect.
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Affiliation(s)
- H L Contreras
- University of California, Irvine, Ecology and Evolutionary Biology Department, 321 Steinhaus Hall, Irvine, CA 92697-2525, United States.
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27
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Clusella‐Trullas S, Terblanche J, Chown S. Phenotypic Plasticity of Locomotion Performance in the Seed HarvesterMessor capensis(Formicidae). Physiol Biochem Zool 2010; 83:519-30. [DOI: 10.1086/651387] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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28
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Kaiser A, Hartzendorf S, Wobschall A, Hetz SK. Modulation of cyclic CO(2) release in response to endogenous changes of metabolism during pupal development of Zophobas rugipes (Coleoptera: Tenebrionidae). JOURNAL OF INSECT PHYSIOLOGY 2010; 56:502-512. [PMID: 19559706 DOI: 10.1016/j.jinsphys.2009.06.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 06/15/2009] [Accepted: 06/16/2009] [Indexed: 05/28/2023]
Abstract
Understanding the mechanisms of gas exchange regulation in insects currently is a hot topic of insect physiology. Endogenous variation of metabolism during pupal development offers a great opportunity to study the regulation of respiratory patterns in insects. Here we show that metabolic rates during pupal development of the tenebrionid beetle Zophobas rugipes reveal a typical U-shaped curve and that, with the exception of 9-day-old pupae, the time between two bursts of CO(2) (interburst phase) was the only parameter of cyclic CO(2) gas exchange patterns that was adjusted to changing metabolic rates. The volume of CO(2) released in a burst was kept constant, suggesting a regulation for accumulation and release of a fixed amount of CO(2) throughout pupal development. We detected a variety of discontinuous and cyclic gas exchange patterns, which were not correlated with any periods of pupal development, suggesting a high among individual variability. An occasional occurrence of continuous CO(2) release patterns at low metabolic rates was very likely caused by single defective non-occluding spiracles.
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Affiliation(s)
- Alexander Kaiser
- Department of Biochemistry, AZCOM, Midwestern University, 19555 N 59th Ave, Glendale, AZ 85308, USA.
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29
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Karise R, Kuusik A, Mänd M, Metspalu L, Williams IH, Hiiesaar K, Luik A, Muljar R, Liiv K. Gas exchange patterns of bumble bee foragers before and after exposing to lowered temperature. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:529-535. [PMID: 19523957 DOI: 10.1016/j.jinsphys.2009.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 05/25/2009] [Accepted: 05/28/2009] [Indexed: 05/27/2023]
Abstract
The gas exchange patterns are known to vary between insect species, individuals and even intra-individually. Using volumetric-manometric and flow-through respirometry combined with IR-actography we studied how periods of low temperature affect the respiratory patterns of bumble bee Bombus terrestris foragers. We have shown, in this study, that there is a change in the respiratory patterns of individual B. terrestris foragers after exposing to low temperatures. The bumble bees seemed to become more inactive. The different respiratory patterns appeared in succession and the transition from one pattern to another was associated with the change from an active to a resting state. Typical patterns after exposition to low temperature were discontinuous gas exchange cycles (DGCs).
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Affiliation(s)
- R Karise
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51014, Tartu, Estonia.
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30
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Terblanche JS, Chown SL. Effects of flow rate and temperature on cyclic gas exchange in tsetse flies (Diptera, Glossinidae). JOURNAL OF INSECT PHYSIOLOGY 2010; 56:513-521. [PMID: 20399350 DOI: 10.1016/j.jinsphys.2009.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 02/19/2009] [Accepted: 02/23/2009] [Indexed: 05/29/2023]
Abstract
Air flow rates may confound the investigation and classification of insect gas exchange patterns. Here we report the effects of flow rates (50, 100, 200, 400 ml min(-1)) on gas exchange patterns in wild-caught Glossina morsitans morsitans from Zambia. At rest, G. m. morsitans generally showed continuous or cyclic gas exchange (CGE) but no evidence of discontinuous gas exchange (DGE). Flow rates had little influence on the ability to detect CGE in tsetse, at least in the present experimental setup and under these laboratory conditions. Importantly, faster flow rates resulted in similar gas exchange patterns to those identified at lower flower rates suggesting that G. m. morsitans did not show DGE which had been incorrectly identified as CGE at lower flow rates. While CGE cycle frequency was significantly different among the four flow rates (p<0.05), the direction of effects was inconsistent. Indeed, inter-individual variation in CGE cycle frequency exceeded flow rate treatment variation. Using a laboratory colony of closely related, similar-sized G. morsitans centralis we subsequently investigated the effects of temperature, gender and feeding status on CGE pattern variation since these factors can influence insect metabolic rates. At 100 ml min(-1) CGE was typical of G. m. centralis at rest, although it was significantly more common in females than in males (57% vs. 43% of 14 individuals tested per gender). In either sex, temperature (20, 24, 28 and 32 degrees C) had little influence on the number of individuals showing CGE. However, increases in metabolic rate with temperature were modulated largely by increases in burst volume and cycle frequency. This is unusual among insects showing CGE or DGE patterns because increases in metabolic rate are usually modulated by increases in frequency, but either no change or a decline in burst volume.
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Affiliation(s)
- John S Terblanche
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa.
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31
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Piiroinen S, Lindström L, Lyytinen A. Resting metabolic rate can vary with age independently from body mass changes in the Colorado potato beetle, Leptinotarsa decemlineata. JOURNAL OF INSECT PHYSIOLOGY 2010; 56:277-282. [PMID: 19896950 DOI: 10.1016/j.jinsphys.2009.10.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Revised: 10/23/2009] [Accepted: 10/27/2009] [Indexed: 05/28/2023]
Abstract
Temperature and mass dependency of insect metabolic rates are well known, while less attention has been given to other factors, such as age. Among insect species that experience seasonal variation in environmental conditions, such as in temperate latitudes, age may also have indirect effects on the metabolic rate. We examined the effect of age on the resting metabolic rate of Leptinotarsa decemlineata during 11 days after adult emergence by using flow-through respirometry. Age had a significant mass-independent effect on metabolic rate of beetles. A twofold increase in metabolic rate occurred during the first 2 days of adult life after which metabolic rate decreased with age relatively slowly. Ten day-old adult beetles had a metabolic rate similar to newly emerged beetles. The beetles have to be able to complete their development and prepare for overwintering during the relatively short favourable summer periods. Therefore, the observed pattern in metabolic rate may reflect physiological changes in the pre-diapause beetles adapted to temperate latitudes.
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Affiliation(s)
- Saija Piiroinen
- Department of Biological and Environmental Science, Centre of Excellence in Evolutionary Research, University of Jyväskylä, PO Box 35, FI-40014 Jyväskylä, Finland.
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32
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Terblanche JS, Clusella-Trullas S, Deere JA, Van Vuuren BJ, Chown SL. Directional evolution of the slope of the metabolic rate-temperature relationship is correlated with climate. Physiol Biochem Zool 2009; 82:495-503. [PMID: 19624273 DOI: 10.1086/605361] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Abstract The evolution of metabolic rate-temperature (MR-T) reaction norms is of fundamental importance to physiological ecology. Metabolic cold adaptation (MCA) predicts that populations or species from cooler environments will have either a higher metabolic rate at a common temperature or steeper MR-T relationships, indicating greater sensitivity of respiratory metabolism to temperature. Support for MCA has been found in some insect species by comparing species or populations differing in latitude. However, the generality of these findings are contentious, with most studies either unable to account for phenotypic plasticity or the evolutionary relatedness of species or populations. Hence, the importance of MCA is vigorously debated from both evolutionary and ecological perspectives. Furthermore, few species, particularly from tropical environments, have been shown to differ in MR-T sensitivity along altitudinal temperature gradients. Here, using four populations of tsetse flies (Glossina pallidipes, Diptera: Glossinidae) from thermally distinct geographic regions, we test the hypothesis that there is evolved variation in MR-T relationships to cold climates. We found that a high-altitude equatorial population from a cool habitat has a steeper MR-T reaction norm. By contrast, other populations from warmer environments in East Africa do not differ with respect to their MR-T reaction norms. Squared-change parsimony analyses, based on the combined mitochondrial 16S rDNA ribosomal subunit and cytochrome c oxidase subunit I (COI), support the hypothesis of adaptive differentiation of MR-T reaction norms in the cool-climate population. Seasonal adjustments or laboratory-temperature-induced phenotypic plasticity changed the intercept of the reaction norm rather than the slope, and thus the observed intraspecific variation in slopes of MR-T reaction norms could not be accounted for by phenotypic plasticity. These results therefore suggest evolutionary adaptation of MR-T reaction norms to cool climates (<22 degrees C) in tsetse and provide novel support for MCA within an insect species.
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Affiliation(s)
- John S Terblanche
- Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa.
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33
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Schimpf NG, Matthews PGD, Wilson RS, White CR. Cockroaches breathe discontinuously to reduce respiratory water loss. J Exp Biol 2009; 212:2773-80. [DOI: 10.1242/jeb.031310] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe reasons why many insects breathe discontinuously at rest are poorly understood and hotly debated. Three adaptive hypotheses attempt to explain the significance of these discontinuous gas exchange cycles (DGCs), whether it be to save water, to facilitate gas exchange in underground environments or to limit oxidative damage. Comparative studies favour the water saving hypothesis and mechanistic studies are equivocal but no study has examined the acclimation responses of adult insects chronically exposed to a range of respiratory environments. The present research is the first manipulative study of such chronic exposure to take a strong-inference approach to evaluating the competing hypotheses according to the explicit predictions stemming from them. Adult cockroaches (Nauphoeta cinerea) were chronically exposed to various treatments of different respiratory gas compositions (O2,CO2 and humidity) and the DGC responses were interpreted in light of the a priori predictions stemming from the competing hypotheses. Rates of mass loss during respirometry were also measured for animals acclimated to a range of humidity conditions. The results refute the hypotheses of oxidative damage and underground gas exchange, and provide evidence supporting the hypothesis that DGCs serve to reduce respiratory water loss: cockroaches exposed to low humidity conditions exchange respiratory gases for shorter durations during each DGC and showed lower rates of body mass loss during respirometry than cockroaches exposed to high humidity conditions.
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Affiliation(s)
- Natalie G. Schimpf
- School of Biological Sciences, Faculty of Biological and Chemical Sciences, University of Queensland, Brisbane 4000, Australia
| | - Philip G. D. Matthews
- School of Biological Sciences, Faculty of Biological and Chemical Sciences, University of Queensland, Brisbane 4000, Australia
| | - Robbie S. Wilson
- School of Biological Sciences, Faculty of Biological and Chemical Sciences, University of Queensland, Brisbane 4000, Australia
| | - Craig R. White
- School of Biological Sciences, Faculty of Biological and Chemical Sciences, University of Queensland, Brisbane 4000, Australia
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34
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Chappell M, Bailey N, Redak R, Antolin M, Zuk M. Metabolic Similarity Despite Striking Behavioral Divergence: Aerobic Performance in Low‐ and High‐Density Forms of the Mormon Cricket. Physiol Biochem Zool 2009; 82:405-18. [DOI: 10.1086/603632] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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35
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Artacho P, Nespolo R. Intrapopulation Variation in the Standard Metabolism of a Terrestrial Mollusc: Repeatability of the CO2Production in the Land SnailHelix aspersa. Physiol Biochem Zool 2009; 82:181-9. [DOI: 10.1086/590222] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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36
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Araújo RA, Guedes RNC, Oliveira MGA, Ferreira GH. Enhanced activity of carbohydrate- and lipid-metabolizing enzymes in insecticide-resistant populations of the maize weevil, Sitophilus zeamais. BULLETIN OF ENTOMOLOGICAL RESEARCH 2008; 98:417-424. [PMID: 18279568 DOI: 10.1017/s0007485308005737] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Insecticide resistance is frequently associated with fitness disadvantages in the absence of insecticides. However, intense past selection with insecticides may allow the evolution of fitness modifier alleles that mitigate the cost of insecticide resistance and their consequent fitness disadvantages. Populations of Sitophilus zeamais with different levels of susceptibility to insecticides show differences in the accumulation and mobilization of energy reserves. These differences may allow S. zeamais to better withstand toxic compounds without reducing the beetles' reproductive fitness. Enzymatic assays with carbohydrate- and lipid-metabolizing enzymes were, therefore, carried out to test this hypothesis. Activity levels of trehalase, glycogen phosphorylase, lipase, glycosidase and amylase were determined in two insecticide-resistant populations showing (resistant cost) or not showing (resistant no-cost) associated fitness cost, and in an insecticide-susceptible population. Respirometry bioassays were also carried out with these weevil populations. The resistant no-cost population showed significantly higher body mass and respiration rate than the other two populations, which were similar. No significant differences in glycogen phosphorylase and glycosidase were observed among the populations. Among the enzymes studied, trehalase and lipase showed higher activity in the resistant cost population. The results obtained in the assays with amylase also indicate significant differences in activity among the populations, but with higher activity in the resistant no-cost population. The inverse activity trends of lipases and amylases in both resistant populations, one showing fitness disadvantage without insecticide exposure and the other not showing it, may underlay the mitigation of insecticide resistance physiological costs observed in the resistant no-cost population. The higher amylase activity observed in the resistant no-cost population may favor energy storage, preventing potential trade-offs between insecticide resistance mechanisms and basic physiological processes in this population, unlike what seems to take place in the resistant cost population.
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Affiliation(s)
- R A Araújo
- Departamento de Biologia Animal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
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37
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Woodman JD, Cooper PD, Haritos VS. Neural regulation of discontinuous gas exchange in Periplaneta americana. JOURNAL OF INSECT PHYSIOLOGY 2008; 54:472-480. [PMID: 18178217 DOI: 10.1016/j.jinsphys.2007.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Revised: 11/22/2007] [Accepted: 11/26/2007] [Indexed: 05/25/2023]
Abstract
Patterns of gas exchange among terrestrial arthropods are highly variable from continuous to discontinuous with discretely partitioned phases. The underlying initiation and co-ordination of these patterns is relatively poorly understood. Here we present a novel method for the simultaneous measurement of central nervous system (CNS) activity of the metathoracic ganglion and VCO(2) in medium to large sized live terrestrial arthropods. Using Periplaneta americana at four oxygen levels (40%, 21%, 10% and 2% at 25 degrees C; n=6 per treatment), we present minimally invasive visualization of nervous output relative to typical resting discontinuous gas exchange (DGE) data for the first time. DGE was maintained when cockroaches were exposed to hyperoxia or moderate hypoxia, but was lost in severe hypoxia. CNS activity was manifested in three signal types: large CNS output coinciding with peak CO(2) production during a burst, moderate CNS output coinciding with CO(2) sawtoothing and fluttering, and minimal CNS activity during the closed phase of DGE in normoxia. Large and moderate CNS outputs were associated with observed abdominal pumping and congruent CO(2) peaks. At 10% oxygen, VCO(2) was significantly elevated during the inter-burst period in association with almost constant moderate CNS output between the periodic large CNS output. At 2% oxygen, DGE and large CNS output are lost to continuous CO(2) release and largely continuous moderate CNS output. As previously reported for this species, a central pattern generator for ventilation in the metathoracic ganglion is supported and we infer the presence of localized oxygen chemoreceptors based on clear CNS response to a change in oxygen tension.
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Affiliation(s)
- James D Woodman
- School of Botany and Zoology, Australian National University, Canberra, ACT, Australia.
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38
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Gray EM, Chown SL. Bias, precision and accuracy in the estimation of cuticular and respiratory water loss: a case study from a highly variable cockroach, Perisphaeria sp. JOURNAL OF INSECT PHYSIOLOGY 2008; 54:169-179. [PMID: 17949739 DOI: 10.1016/j.jinsphys.2007.08.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 08/27/2007] [Accepted: 08/28/2007] [Indexed: 05/25/2023]
Abstract
We compared the precision, bias and accuracy of two techniques that were recently proposed to estimate the contributions of cuticular and respiratory water loss to total water loss in insects. We performed measurements of VCO2 and VH2O in normoxia, hyperoxia and anoxia using flow through respirometry on single individuals of the highly variable cockroach Perisphaeria sp. to compare estimates of cuticular and respiratory water loss (CWL and RWL) obtained by the VH2O-VCO2 y-intercept method with those obtained by the hyperoxic switch method. Precision was determined by assessing the repeatability of values obtained whereas bias was assessed by comparing the methods' results to each other and to values for other species found in the literature. We found that CWL was highly repeatable by both methods (R0.88) and resulted in similar values to measures of CWL determined during the closed-phase of discontinuous gas exchange (DGE). Repeatability of RWL was much lower (R=0.40) and significant only in the case of the hyperoxic method. RWL derived from the hyperoxic method is higher (by 0.044 micromol min(-1)) than that obtained from the method traditionally used for measuring water loss during the closed-phase of DGE, suggesting that in the past RWL may have been underestimated. The very low cuticular permeability of this species (3.88 microg cm(-2) h(-1) Torr(-1)) is reasonable given the seasonally hot and dry habitat where it lives. We also tested the hygric hypothesis proposed to account for the evolution of discontinuous gas exchange cycles and found no effect of respiratory pattern on RWL, although the ratio of mean VH2O to VCO2 was higher for continuous patterns compared with discontinuous ones.
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Affiliation(s)
- Emilie M Gray
- Department of Botany and Zoology, Centre for Invasion Biology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
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Kovac H, Stabentheiner A, Hetz SK, Petz M, Crailsheim K. Respiration of resting honeybees. JOURNAL OF INSECT PHYSIOLOGY 2007; 53:1250-61. [PMID: 17707395 PMCID: PMC3227735 DOI: 10.1016/j.jinsphys.2007.06.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 06/25/2007] [Accepted: 06/25/2007] [Indexed: 05/16/2023]
Abstract
The relation between the respiratory activity of resting honeybees and ambient temperature (T(a)) was investigated in the range of 5-40 degrees C. Bees were kept in a temperature controlled flow through respirometer chamber where their locomotor and endothermic activity, as well as abdominal ventilatory movements was recorded by infrared thermography. Surprisingly, true resting bees were often weakly endothermic (thorax surface up to 2.8 degrees C warmer than abdomen) at a T(a) of 14-30 degrees C. Above 33 degrees C many bees cooled their body via evaporation from their mouthparts. A novel mathematical model allows description of the relationship of resting (standard) metabolic rate and temperature across the entire functional temperature range of bees. In chill coma (<11 degrees C) bees were ectothermic and CO(2) release was mostly continuous. CO(2) release rate (nls(-1)) decreased from 9.3 at 9.7 degrees C to 5.4 at 5 degrees C. At a T(a) of >11 degrees C CO(2) was released discontinuously. In the bees' active temperature range mean CO(2) production rate (nls(-1)) increased sigmoidally (10.6 at 14.1 degrees C, 24.1 at 26.5 degrees C, and 55.2 at 38.1 degrees C), coming to a halt towards the upper lethal temperature. This was primarily accomplished by an exponential increase in gas exchange frequency (0.54 and 3.1 breaths min(-1) at 14.1 and 38.1 degrees C) but not in released CO(2) volume per respiratory cycle (1487 and 1083 nl cycle(-1) at 14.1 and 38.1 degrees C). Emission of CO(2) bursts was mostly (98%) accompanied by abdominal ventilation movements even in small CO(2) bursts. Larger bursts coincided with a longer duration of active ventilation. An increased amount of CO(2) expelled per unit time of ventilation indicates a higher efficiency of ventilation at high ambient temperatures.
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Affiliation(s)
- Helmut Kovac
- Institut für Zoologie, Karl-Franzens-Universität Graz, Universitätsplatz 2, A-8010 Graz, Austria
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Stephenson R, Chu KM, Lee J. Prolonged deprivation of sleep-like rest raises metabolic rate in the Pacific beetle cockroach, Diploptera punctata (Eschscholtz). ACTA ACUST UNITED AC 2007; 210:2540-7. [PMID: 17601958 DOI: 10.1242/jeb.005322] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Rats respond to sustained sleep deprivation with increased mortality preceded by a rise in resting metabolic rate that may or may not be attributed to dysfunction of the thermoregulatory system. The present study was designed to test the hypothesis that deprivation of sleep-like rest will lead to increased metabolic rate in an ectothermic insect, the Pacific beetle cockroach. A mild alerting stimulus consisting of a brief <1% pulse of CO2 and simultaneous 2 s rotation (1 cm motion) of the animal chamber consistently prevented the adoption of a sleep-like resting posture in cockroaches. Two groups of 15 male adult cockroaches were studied; a group targeted for deprivation of sleep-like rest (SD) was presented with one stimulus per minute continuously, and a group of stimulus controls (SC) was given the same number of stimuli per day but scheduled such that the animals received a 3 h interval without stimuli four times per day. This protocol led to significantly increased mortality in the SD group beginning on day 17 (averaging 0.57 deaths per day thereafter), but not in the SC group (averaging 0.17 deaths per day throughout). Oxygen consumption (VO2) increased significantly after 4 weeks in the SD group but not the SC group. VO2 was 82% above pre-deprivation baseline after 35 days in the SD group (P=0.009). Body mass was unchanged throughout. We conclude that sleep-like rest is essential for long-term viability in insects and that prolonged vigilance leads to an increase in whole-animal metabolic rate in this ectothermic species.
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Affiliation(s)
- Richard Stephenson
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, M5S 3G5, Canada.
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41
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FINSTAD AG, FORSETH T, UGEDAL O, NÆSJE TF. Metabolic rate, behaviour and winter performance in juvenile Atlantic salmon. Funct Ecol 2007. [DOI: 10.1111/j.1365-2435.2007.01291.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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42
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Nespolo RF, Franco M. Whole-animal metabolic rate is a repeatable trait: a meta-analysis. ACTA ACUST UNITED AC 2007; 210:2000-5. [PMID: 17515425 DOI: 10.1242/jeb.02780] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Repeatability studies are gaining considerable interest among physiological ecologists, particularly in traits affected by high environmental/residual variance, such as whole-animal metabolic rate (MR). The original definition of repeatability, known as the intraclass correlation coefficient, is computed from the components of variance obtained in a one-way ANOVA on several individuals from which two or more measurements are performed. An alternative estimation of repeatability, popular among physiological ecologists, is the Pearson product-moment correlation between two consecutive measurements. However, despite the more than 30 studies reporting repeatability of MR, so far there is not a definite synthesis indicating: (1) whether repeatability changes in different types of animals; (2) whether some kinds of metabolism are more repeatable than others; and most important, (3) whether metabolic rate is significantly repeatable. We performed a meta-analysis to address these questions, as well as to explore the historical trend in repeatability studies. Our results show that metabolic rate is significantly repeatable and its effect size is not statistically affected by any of the mentioned factors (i.e. repeatability of MR does not change in different species, type of metabolism, time between measurements, and number of individuals). The cumulative meta-analysis revealed that repeatability studies in MR have already reached an asymptotical effect size with no further change either in its magnitude and/or variance (i.e. additional studies will not contribute significantly to the estimator). There was no evidence of strong publication bias.
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Affiliation(s)
- Roberto F Nespolo
- Instituto de Ecología y Evolución, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.
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White CR, Blackburn TM, Terblanche JS, Marais E, Gibernau M, Chown SL. Evolutionary responses of discontinuous gas exchange in insects. Proc Natl Acad Sci U S A 2007; 104:8357-61. [PMID: 17485672 PMCID: PMC1895954 DOI: 10.1073/pnas.0608968104] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Indexed: 11/18/2022] Open
Abstract
The discontinuous gas-exchange cycles (DGCs) observed in many quiescent insects have been a cause of debate for decades, but no consensus on their evolutionary origin or adaptive significance has been achieved. Nevertheless, three main adaptive hypotheses have emerged: (i) the hygric hypothesis suggests that DGCs reduce respiratory water loss; (ii) the chthonic hypothesis suggests that DGCs facilitate gas exchange during environmental hypoxia, hypercapnia, or both; and (iii) the oxidative-damage hypothesis suggests that DGCs minimize oxidative tissue damage. However, most work conducted to date has been based on single-species investigations or nonphylogenetic comparative analyses of few species, despite calls for a strong-inference, phylogenetic approach. Here, we adopt such an approach by using 76 measurements of 40 wild-caught species to examine macrophysiological variation in DGC duration in insects. Potential patterns of trait variation are first identified on the basis of the explicit a priori predictions of each hypothesis, and the best phylogenetic generalized least-squares fit of the candidate models to the data is selected on the basis of Akaike's information criterion. We find a significant positive relationship between DGC duration and habitat temperature and an important interaction between habitat temperature and precipitation. This result supports the hygric hypothesis. We conclude that the DGCs of insects reduce respiratory water loss while ensuring adequate gas exchange.
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Affiliation(s)
- Craig R White
- Department of Environmental Biology, School of Earth and Environmental Sciences, University of Adelaide, Adelaide 5005, Australia.
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Woodman JD, Cooper PD, Haritos VS. Cyclic gas exchange in the giant burrowing cockroach, Macropanesthia rhinoceros: effect of oxygen tension and temperature. JOURNAL OF INSECT PHYSIOLOGY 2007; 53:497-504. [PMID: 17374539 DOI: 10.1016/j.jinsphys.2007.01.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 01/29/2007] [Accepted: 01/29/2007] [Indexed: 05/14/2023]
Abstract
The giant burrowing cockroach, Macropanesthia rhinoceros, is endemic to north-eastern Australia and excavates a permanent burrow up to 1m deep into soil. Using flow-through respirometry, we investigated gas exchange and water loss at three different oxygen tensions (21%, 10% and 2% at 20 degrees C) and temperatures (10, 20 and 30 degrees C at 21% oxygen). M. rhinoceros employ cyclic gas exchange (CGE) making the species by far the largest insect known to engage in discontinuous ventilation. CGE featured rhythmic bursts of CO(2) dispersed among inter-burst periods of reduced output. CGE was most commonly observed at 20 degrees C and degraded at <10% oxygen. Mild hypoxia (10% oxygen) resulted in a lengthening of the burst period by approximately two-fold; this result is complementary to oxygen consumption data that suggests that the burst period is important in oxygen uptake. When exposed to severe hypoxia (2% oxygen), CGE was degraded to a more erratic continuous pattern. Also, during severe hypoxia, total water loss increased significantly, although CO(2) release was maintained at the same level as in 21% oxygen. During CGE, an increase in temperature from 10 to 20 degrees C caused both water loss and CO(2) output to double; from 20 to 30 degrees C, CO(2) output again doubled but water loss increased by only 31%.
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Affiliation(s)
- James D Woodman
- CSIRO Entomology, GPO Box 1700, Canberra ACT 2601, Australia.
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Sláma K, Sobotník J, Hanus R. Respiratory concerts revealed by scanning microrespirography in a termite Prorhinotermes simplex (Isoptera: Rhinotermitidae). JOURNAL OF INSECT PHYSIOLOGY 2007; 53:295-311. [PMID: 17306293 DOI: 10.1016/j.jinsphys.2006.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 12/04/2006] [Accepted: 12/06/2006] [Indexed: 05/14/2023]
Abstract
Respiratory metabolism of different developmental stages (larvae, pseudergates, nymphs, soldiers, neotenic reproductives; 0.6-4.5 mg body mass) of Prorhinotermes simplex was individually monitored by scanning respirographic method sensitive to subnanoliter amounts of O(2) consumption or CO(2) output per minute. Specimens exposed to dry air after removal from the colony performed enormously large, discontinuous bursts of CO(2) lasting usually 2 min. The volume of CO(2) produced during the burst often surpassed the volume of the whole body and it was 10- to 20-fold in excess of the air-filled endogenous tracheal volume. The initial velocity of CO(2) production during the burst was more than 90-fold faster in comparison to O(2) consumption. In the presence of enough moisture within the respiratory vessel, the termites breathed continuously without any larger outburst of CO(2). This fact fully corroborates validity of the so-called water retention theory in discontinuous CO(2) release. The highest rates of O(2) consumption were found in the second instar larvae (0.9 mg, 1000-2000 microl O(2)/g/h), the soldier caste was intermediate (700 microl O(2)/g/h) while pseudergates and neotenic reproductives consumed between 300 and 600 microl O(2)/g/h, at 25 degrees C. All developmental stages feeding on a cellulose diet had CO(2)/O(2) values (RQ) over 1 (1.2-1.4, i.e. carbohydrate metabolism), pigmented soldiers fed by the workers had RQ around 0.75 (predominating lipid or protein metabolism). The unusually large, sudden eruptions of CO(2) in specimens exposed to dry air allow us to make the following conclusions: (1) the bursts were due to special chemical processes, such as by enzymatic hydration of carbonic acid by carbonic anhydrase and; (2) the bulk of chemically evolved gaseous CO(2) escaped from the body by a mass flow supported by active ventilation, not by a passive diffusion. These results demonstrated that the periodic emissions of CO(2) and the associated homeostatic regulation of the respiratory acidaemia were under perfect physiological control. The termites could thus actively select the type of CO(2) release best suited to the extant environmental or internal physiological conditions, i.e. from a completely continuous respiration to occasionally cyclic or completely discontinuous CO(2) release.
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Affiliation(s)
- K Sláma
- Institute of Entomology, Biology Center of the Czech Academy of Sciences, Drnovská 507, 16100 Prana 6, Czech Republic
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46
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Nespolo RF, Artacho P, Castañeda LE. Cyclic gas-exchange in the Chilean red cricket: inter-individual variation and thermal dependence. J Exp Biol 2007; 210:668-75. [PMID: 17267652 DOI: 10.1242/jeb.001966] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
One of the most puzzling features of respiration in insects is cyclic gas exchange (CGE, the extreme form of discontinuous gas exchange-cycles, DGC), a periodic respiratory pattern that appeared independently several times in the evolution of arthropods. Although it is a striking feature of insects and some non-insect species, to date there is no clear knowledge of how widespread it is, or its adaptive significance. Here we show for the first time that a cricket (Cratomelus armatus) from the Stenopelmatidae family exhibits CGE. C. armatus shows a conspicuous, convective O-phase, with significantly repeatable ventilatory period and O-phase duration (intraclass correlation coefficients of 0.51 and 0.74, respectively). Also, C. armatus exhibits high variation in the CGE patterns, ranging from continuous to highly periodic records, sometimes including the classic F-phase. No record went to zero and we found significant (inverse) effects of ambient temperature on O-phase duration but not on the ventilatory period. Average V̇CO2 and O-phase amplitude (i.e. mean V̇CO2 of the peaks) increased with temperature whereas the amplitude of the interburst did not change significantly with ambient temperature. C. armatus is a species that lives below ground in humid forests, so our results support the chthonic-hygric hypothesis (i.e. facilitation of gas exchange under hypoxic and hypercapnic conditions, minimizing evaporative water loss), although this assertion needs to be confirmed statistically by a strong inference approach.
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Affiliation(s)
- Roberto F Nespolo
- Instituto de Ecología y Evolución, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.
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Quinlan MC, Gibbs AG. Discontinuous gas exchange in insects. Respir Physiol Neurobiol 2006; 154:18-29. [PMID: 16870512 DOI: 10.1016/j.resp.2006.04.004] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Revised: 03/31/2006] [Accepted: 04/07/2006] [Indexed: 11/28/2022]
Abstract
Insect respiratory physiology has been studied for many years, and interest in this area of insect biology has become revitalized recently for a number of reasons. Technical advances have greatly improved the precision, accuracy and ease with which gas exchange can be measured in insects. This has made it possible to go beyond classic models such as lepidopteran pupae and examine a far greater diversity of species. One striking result of recent work is the realization that insect gas exchange patterns are much more diverse than formerly recognized. Current work has also benefited from the inclusion of comparative methods that rigorously incorporate phylogenetic, ecological and life history information. We discuss these advances in the context of the classic respiratory pattern of insects, discontinuous gas exchange. This mode of gas exchange was exhaustively described in moth pupae in the 1950s and 1960s. Early workers concluded that discontinuous gas exchange was an adaptation to reduce respiratory water loss. This idea is no longer universally accepted, and several competing hypotheses have been proposed. We discuss the genesis of these alternative hypotheses, and we identify some of the predictions that might be used to test them. We are pleased to report that what was once a mature discipline, in which the broad parameters and adaptive significance of discontinuous gas exchange were thought to be well understood, is now a thriving and vigorous field of research.
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Affiliation(s)
- Michael C Quinlan
- Department of Basic Science, Midwestern University, 19555 North 59th Avenue, Glendale, AZ 85308, USA.
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Lighton JRB, Ottesen EA. To DGC or not to DGC: oxygen guarding in the termite Zootermopsis nevadensis (Isoptera: Termopsidae). ACTA ACUST UNITED AC 2006; 208:4671-8. [PMID: 16326948 DOI: 10.1242/jeb.01934] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The ability of some insects to engage in complex orchestrations of tracheal gas exchange has been well demonstrated, but its evolutionary origin remains obscure. According to a recently proposed hypothesis, insects may employ spiracular control of gas exchange to guard tissues against long-term oxidative damage by using the discontinuous gas-exchange cycle (DGC) to limit internal oxygen partial pressure (PO2). This manuscript describes a different approach to oxygen guarding in the lower termite Zootermopsis nevadensis. These insects do not display a DGC but respond to elevated oxygen concentrations by restricting spiracular area, resulting in a transient decline in CO2 emission. High internal CO2 concentrations are then maintained; restoring normoxia results in a transient reciprocal increase in CO2 emission caused by release of excess endotracheal CO2. These changes in spiracular area reflect active guarding of low internal O2 concentrations and demonstrate that regulation of endotracheal hypoxia takes physiological priority over prevention of CO2 build-up. This adaptation may reflect the need to protect oxygen-sensitive symbionts (or, gut bug guarding). Termites may eschew the DGC because periodic flushing of the tracheal system with air may harm the obligate anaerobes upon which the lower termites depend for survival on their native diet of chewed wood.
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Affiliation(s)
- John R B Lighton
- Department of Biology, University of Nevada at Las Vegas, NV 89154-4004, USA.
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White CR, Matthews PGD, Seymour RS. In situ measurement of calling metabolic rate in an Australian mole cricket, Gryllotalpa monanka. Comp Biochem Physiol A Mol Integr Physiol 2006; 150:217-21. [PMID: 17049289 DOI: 10.1016/j.cbpa.2006.08.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2006] [Revised: 07/31/2006] [Accepted: 08/14/2006] [Indexed: 11/29/2022]
Abstract
Examination of the energetics of sound production usually requires measurement of species that will produce normal calls under unnatural circumstances. Such measurements are potentially compromised by stress-related changes in calling input (through a reduction in calling effort) or output (through forced use of sub-optimal singing burrows). To determine if such measurements are indeed affected by abstraction from a natural setting, we measured the energetics of song production in undisturbed mole crickets Gryllotalpa monanka and employed a new approach where the animal's singing chamber replaces the respirometry chamber normally used in studies of this type. It was therefore possible to measure metabolic rate (MR) of calling crickets in situ for animals within self-constructed burrows under natural conditions. Calling MR measured under these conditions averaged 13.5-fold higher than standard MR and 2.2-fold higher than MR measured during burrowing in the lab. The calling MR of G. monanka was similar to that measured for other calling insects, and to endothermic insects, but was only 10% of that allometrically predicted for a similarly sized insect (0.89 g) during flight. A male mole cricket is estimated to consume 5.9 ml of oxygen during construction of a calling burrow and a 1-h calling bout; by comparison, a flying female would consume a similar volume in less than 6 min.
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Affiliation(s)
- Craig R White
- Environmental Biology School of Earth and Environmental Sciences The University of Adelaide, Adelaide, SA 5005, Australia.
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50
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Gray EM, Bradley TJ. Evidence from mosquitoes suggests that cyclic gas exchange and discontinuous gas exchange are two manifestations of a single respiratory pattern. J Exp Biol 2006; 209:1603-11. [PMID: 16621941 DOI: 10.1242/jeb.02181] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYIn this paper we demonstrate that the apparent pattern of gas exchange in insects, as observed using flow-through respirometry, is strongly affected by the rate of flow of air through the system. This is true not only because of the time constant of the respiratory chamber in which the insect resides, but also due to the effect of flow rate on the residence time of air as it passes through the detection chamber in the gas analyzer. It is demonstrated that insects respiring with a discontinuous gas exchange pattern can appear to be using a cyclic respiratory pattern. The effects of flow rate on the respiratory pattern discerned are illustrated using the mosquito Culiseta inornata. It is demonstrated that these mosquitoes respire discontinuously. They are among the smallest insects to date in which the discontinuous gas exchange cycle has been observed.
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Affiliation(s)
- Emilie M Gray
- Department of Ecology and Evolutionary Biology, University of California, Irvine, 92697-2525, USA
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