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Cease AJ. How Nutrients Mediate the Impacts of Global Change on Locust Outbreaks. ANNUAL REVIEW OF ENTOMOLOGY 2024; 69:527-550. [PMID: 38270985 DOI: 10.1146/annurev-ento-120220-110415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
Locusts are grasshoppers that can migrate en masse and devastate food security. Plant nutrient content is a key variable influencing population dynamics, but the relationship is not straightforward. For an herbivore, plant quality depends not only on the balance of nutrients and antinutrients in plant tissues, which is influenced by land use and climate change, but also on the nutritional state and demands of the herbivore, as well as its capacity to extract nutrients from host plants. In contrast to the concept of a positive relationship between nitrogen or protein concentration and herbivore performance, a five-decade review of lab and field studies indicates that equating plant N to plant quality is misleading because grasshoppers respond negatively or neutrally to increasing plant N just as often as they respond positively. For locusts specifically, low-N environments are actually beneficial because they supply high energy rates that support migration. Therefore, intensive land use, such as continuous grazing or cropping, and elevated ambient CO2 levels that decrease the protein:carbohydrate ratios of plants are predicted to broadly promote locust outbreaks.
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Affiliation(s)
- Arianne J Cease
- School of Sustainability, School of Life Sciences, and Global Locust Initiative, Arizona State University, Tempe, Arizona, USA;
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2
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Polymeropoulos ET, Milsom WK. Editorial: Untangling the oxygen transport cascade: a tribute to Peter Frappell (Frapps). J Comp Physiol B 2021; 191:973-978. [PMID: 34463812 DOI: 10.1007/s00360-021-01401-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 10/20/2022]
Abstract
This collection of research articles was put together in honour of respiratory physiologist Professor Peter Frappell's (Frapps's) academic achievements. It encompasses various topics relating to the oxygen transport cascade, which was central to Frapps' career as a comparative physiologist. This issue highlights the diversity and outreach of his influence on the field and his pioneering spirit; promoting novel perspectives, methodologies and research techniques. This issue also demonstrates how Frapps' knowledge and scientific findings answered some of the fundamental questions within the field of respiratory physiology while creating and fostering a rather unique work atmosphere in the laboratories he led. We thank Frapps for the contributions he has made and the friendships he has nurtured over his career. Cheers, Frapps - we love you mate!
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Affiliation(s)
- Elias T Polymeropoulos
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Hobart, TAS, 7001, Australia.
| | - William K Milsom
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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Cavigliasso F, Dupuis C, Savary L, Spangenberg JE, Kawecki TJ. Experimental evolution of post-ingestive nutritional compensation in response to a nutrient-poor diet. Proc Biol Sci 2020; 287:20202684. [PMID: 33259760 PMCID: PMC7739944 DOI: 10.1098/rspb.2020.2684] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The geometric framework of nutrition predicts that populations restricted to a single imbalanced diet should evolve post-ingestive nutritional compensation mechanisms bringing the blend of assimilated nutrients closer to physiological optimum. The evolution of such nutritional compensation is thought to be mainly driven by the ratios of major nutrients rather than overall nutritional content of the diet. We report experimental evolution of divergence in post-ingestive nutritional compensation in populations of Drosophila melanogaster adapted to diets that contained identical imbalanced nutrient ratios but differed in total nutrient concentration. Larvae from 'Selected' populations maintained for over 200 generations on a nutrient-poor diet with a 1 : 13.5 protein : carbohydrate ratio showed enhanced assimilation of nitrogen from yeasts and reduced assimilation of carbon from sucrose than 'Control' populations evolved on a diet with the same nutrient ratio but fourfold greater nutrient concentration. Compared to the Controls, the Selected larvae also accumulated less triglycerides relative to protein. This implies that the Selected populations evolved a higher assimilation rate of amino acids from the poor imbalanced diet and a lower assimilation of carbohydrates than Controls. Thus, the evolution of nutritional compensation may be driven by changes in total nutrient abundance, even if the ratios of different nutrients remain unchanged.
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Affiliation(s)
- Fanny Cavigliasso
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Cindy Dupuis
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Loriane Savary
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Jorge E Spangenberg
- Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland
| | - Tadeusz J Kawecki
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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Short K, Derrickson EM. Compensatory changes in villus morphology of lactating Mus musculus in response to insufficient dietary protein. J Exp Biol 2020; 223:jeb210823. [PMID: 32165430 DOI: 10.1242/jeb.210823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 02/27/2020] [Indexed: 11/20/2022]
Abstract
Energetic challenges match intestinal size to dietary intake but less is known about how the intestine responds to specific macronutrient challenges. We examined how intestinal size responds to insufficient dietary protein at the microscopic level. Villi, enterocytes and surface area were measured across the length of the small intestine in non-reproductive and lactating Mus musculus fed isocaloric control or protein-deficient diets. Lactating mice on the protein-deficient diet exhibited a 24% increase in villus height and a 30% increase in enterocyte width in the proximal small intestine and an overall similar increase in surface area; on the control diet, changes in villus height were localized in the mid region. Flexibility localized to the proximal small intestine suggests that enterokinase, a localized enzyme, may be a candidate enzyme that promotes compensation for a protein-deficient diet. Such flexibility could allow species to persist in the face of anthropogenically induced changing dietary profiles.
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Affiliation(s)
- Kay Short
- Department of Biology, Loyola University Maryland, 4501 N. Charles St, Baltimore, MD 21120, USA
| | - Elissa M Derrickson
- Department of Biology, Loyola University Maryland, 4501 N. Charles St, Baltimore, MD 21120, USA
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5
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Littlefair JE, Knell RJ. Within- and Trans-Generational Effects of Variation in Dietary Macronutrient Content on Life-History Traits in the Moth Plodia interpunctella. PLoS One 2016; 11:e0168869. [PMID: 28033396 PMCID: PMC5199116 DOI: 10.1371/journal.pone.0168869] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 12/07/2016] [Indexed: 11/18/2022] Open
Abstract
It is increasingly clear that parental environment can play an important role in determining offspring phenotype. These “transgenerational effects” have been linked to many different components of the environment, including toxin exposure, infection with pathogens and parasites, temperature and food quality. In this study, we focus on the latter, asking how variation in the quantity and quality of nutrition affects future generations. Previous studies have shown that artificial diets are a useful tool to examine the within-generation effects of variation in macronutrient content on life history traits, and could therefore be applied to investigations of the transgenerational effects of parental diet. Synthetic diets varying in total macronutrient content and protein: carbohydrate ratios were used to examine both within- and trans-generational effects on life history traits in a generalist stored product pest, the Indian meal moth Plodia interpunctella. The macronutrient composition of the diet was important for shaping within-generation life history traits, including pupal weight, adult weight, and phenoloxidase activity, and had indirect effects via maternal weight on fecundity. Despite these clear within-generation effects on the biology of P. interpunctella, diet composition had no transgenerational effects on the life history traits of offspring. P. interpunctella mothers were able to maintain their offspring quality, possibly at the expense of their own somatic condition, despite high variation in dietary macronutrient composition. This has important implications for the plastic biology of this successful generalist pest.
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Affiliation(s)
- Joanne E. Littlefair
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
- * E-mail:
| | - Robert J. Knell
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
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Littlefair JE, Laughton AM, Knell RJ. Maternal pathogen exposure causes diet- and pathogen-specific transgenerational costs. OIKOS 2016. [DOI: 10.1111/oik.03430] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Joanne E. Littlefair
- School of Biological and Chemical Sciences; Queen Mary Univ. of London; Fogg Building, Mile End Road London E1 4NS UK
| | - Alice M. Laughton
- School of Biological and Chemical Sciences; Queen Mary Univ. of London; Fogg Building, Mile End Road London E1 4NS UK
| | - Robert J. Knell
- School of Biological and Chemical Sciences; Queen Mary Univ. of London; Fogg Building, Mile End Road London E1 4NS UK
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Ponton F, Wilson K, Holmes A, Raubenheimer D, Robinson KL, Simpson SJ. Macronutrients mediate the functional relationship between Drosophila and Wolbachia. Proc Biol Sci 2016; 282:20142029. [PMID: 25520356 DOI: 10.1098/rspb.2014.2029] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Wolbachia are maternally inherited bacterial endosymbionts that naturally infect a diverse array of arthropods. They are primarily known for their manipulation of host reproductive biology, and recently, infections with Wolbachia have been proposed as a new strategy for controlling insect vectors and subsequent human-transmissible diseases. Yet, Wolbachia abundance has been shown to vary greatly between individuals and the magnitude of the effects of infection on host life-history traits and protection against infection is correlated to within-host Wolbachia abundance. It is therefore essential to better understand the factors that modulate Wolbachia abundance and effects on host fitness. Nutrition is known to be one of the most important mediators of host-symbiont interactions. Here, we used nutritional geometry to quantify the role of macronutrients on insect-Wolbachia relationships in Drosophila melanogaster. Our results show fundamental interactions between diet composition, host diet selection, Wolbachia abundance and effects on host lifespan and fecundity. The results and methods described here open a new avenue in the study of insect-Wolbachia relationships and are of general interest to numerous research disciplines, ranging from nutrition and life-history theory to public health.
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Affiliation(s)
- Fleur Ponton
- School of Biological Sciences, The University of Sydney, New South Wales 2006, Australia Charles Perkins Centre, The University of Sydney, New South Wales 2006, Australia
| | - Kenneth Wilson
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - Andrew Holmes
- Charles Perkins Centre, The University of Sydney, New South Wales 2006, Australia School of Molecular Bioscience, The University of Sydney, New South Wales 2006, Australia
| | - David Raubenheimer
- School of Biological Sciences, The University of Sydney, New South Wales 2006, Australia Charles Perkins Centre, The University of Sydney, New South Wales 2006, Australia Faculty of Veterinary Science, The University of Sydney, New South Wales 2006, Australia
| | - Katie L Robinson
- School of Biological Sciences, The University of Sydney, New South Wales 2006, Australia Charles Perkins Centre, The University of Sydney, New South Wales 2006, Australia
| | - Stephen J Simpson
- School of Biological Sciences, The University of Sydney, New South Wales 2006, Australia Charles Perkins Centre, The University of Sydney, New South Wales 2006, Australia
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Ruthrauff DR, Dekinga A, Gill RE, van Gils JA, Piersma T. Ways to be different: foraging adaptations that facilitate higher intake rates in a northerly wintering shorebird compared with a low-latitude conspecific. ACTA ACUST UNITED AC 2015; 218:1188-97. [PMID: 25714569 DOI: 10.1242/jeb.108894] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 02/12/2015] [Indexed: 11/20/2022]
Abstract
At what phenotypic level do closely related subspecies that live in different environments differ with respect to food detection, ingestion and processing? This question motivated an experimental study on rock sandpipers (Calidris ptilocnemis). The species' nonbreeding range spans 20 deg of latitude, the extremes of which are inhabited by two subspecies: C. p. ptilocnemis that winters primarily in upper Cook Inlet, Alaska (61°N) and C. p. tschuktschorum that overlaps slightly with C. p. ptilocnemis but whose range extends much farther south (∼40°N). In view of the strongly contrasting energetic demands of their distinct nonbreeding distributions, we conducted experiments to assess the behavioral, physiological and sensory aspects of foraging and we used the bivalve Macoma balthica for all trials. C. p. ptilocnemis consumed a wider range of prey sizes, had higher maximum rates of energy intake, processed shell waste at higher maximum rates and handled prey more quickly. Notably, however, the two subspecies did not differ in their abilities to find buried prey. The subspecies were similar in size and had equally sized gizzards, but the more northern ptilocnemis individuals were 10-14% heavier than their same-sex tschuktschorum counterparts. The higher body mass in ptilocnemis probably resulted from hypertrophy of digestive organs (e.g. intestine, liver) related to digestion and nutrient assimilation. Given the previously established equality of the metabolic capacities of the two subspecies, we propose that the high-latitude nonbreeding range of ptilocnemis rock sandpipers is primarily facilitated by digestive (i.e. physiological) aspects of their foraging ecology rather than behavioral or sensory aspects.
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Affiliation(s)
- Daniel R Ruthrauff
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK 99508, USA Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, Den Burg, Texel 1790 AB, The Netherlands
| | - Anne Dekinga
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, Den Burg, Texel 1790 AB, The Netherlands
| | - Robert E Gill
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK 99508, USA
| | - Jan A van Gils
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, Den Burg, Texel 1790 AB, The Netherlands
| | - Theunis Piersma
- Department of Marine Ecology, NIOZ Royal Netherlands Institute for Sea Research, P.O. Box 59, Den Burg, Texel 1790 AB, The Netherlands Chair in Global Flyway Ecology, Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, P.O. Box 11103, Groningen 9700 CC, The Netherlands
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Simpson SJ, Clissold FJ, Lihoreau M, Ponton F, Wilder SM, Raubenheimer D. Recent advances in the integrative nutrition of arthropods. ANNUAL REVIEW OF ENTOMOLOGY 2015; 60:293-311. [PMID: 25341097 DOI: 10.1146/annurev-ento-010814-020917] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In this review we highlight recent advances in four areas in which nutrition shapes the relationships between organisms: between plants and herbivores, between hosts and their microbiota, between individuals within groups and societies, and between species within food webs. We demonstrate that taking an explicitly multidimensional view of nutrition and employing the logic of the geometric framework for nutrition provide novel insights and offer a means of integration across different levels of organization, from individuals to ecosystems.
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Xu P, Liu Y, Graham RI, Wilson K, Wu K. Densovirus is a mutualistic symbiont of a global crop pest (Helicoverpa armigera) and protects against a baculovirus and Bt biopesticide. PLoS Pathog 2014; 10:e1004490. [PMID: 25357125 PMCID: PMC4214819 DOI: 10.1371/journal.ppat.1004490] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 09/26/2014] [Indexed: 01/01/2023] Open
Abstract
Mutualistic associations between symbiotic bacteria and their hosts are common within insect systems. However, viruses are often considered as pathogens even though some have been reported to be beneficial to their hosts. Herein, we report a novel densovirus, Helicoverpa armigera densovirus-1 (HaDNV-1) that appears to be beneficial to its host. HaDNV-1 was found to be widespread in wild populations of H. armigera adults (>67% prevalence between 2008 and 2012). In wild larval populations, there was a clear negative interaction between HaDNV-1 and H. armigera nucleopolyhedrovirus (HaNPV), a baculovirus that is widely used as a biopesticide. Laboratory bioassays revealed that larvae hosting HaDNV-1 had significantly enhanced resistance to HaNPV (and lower viral loads), and that resistance to Bacillus thuringiensis (Bt) toxin was also higher at low doses. Laboratory assays indicated that the virus was mainly distributed in the fat body, and could be both horizontally- and vertically-transmitted, though the former occurred only at large challenge doses. Densovirus-positive individuals developed more quickly and had higher fecundity than uninfected insects. We found no evidence for a negative effect of HaDNV-1 infection on H. armigera fitness-related traits, strongly suggesting a mutualistic interaction between the cotton bollworm and its densovirus. The old world cotton bollworm, Helicoverpa armigera, is one of the most significant pests of crops throughout Asia, Europe, Africa and Australia. Herein, we report a novel densovirus (HaDNV-1) which was widely distributed in wild populations of H. armigera and was beneficial to its host by increasing larval and pupal development rates, female lifespan and fecundity, suggesting a mutualistic interaction between the cotton bollworm and HaDNV-1. The cotton bollworm is currently widely controlled by the biopesticides Bacillus thuringiensis (Bt) toxin and the baculovirus HaNPV. It is therefore important to estimate the risk that the symbiotic virus will negatively impact on the efficiency of these biopesticides. Field and laboratory results suggest that HaDNV-1 infection significantly increases larval resistance to HaNPV and Bt toxin. These results have important implications for the selection of biopesticides for this species, and highlight the need for greater research into the elegant microbial interactions that may impact host individual and population dynamics.
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Affiliation(s)
- Pengjun Xu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, People's Republic of China
| | - Yongqiang Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
| | - Robert I. Graham
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Kenneth Wilson
- Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Kongming Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China
- * E-mail:
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Clissold FJ, Kertesz H, Saul AM, Sheehan JL, Simpson SJ. Regulation of water and macronutrients by the Australian plague locust, Chortoicetes terminifera. JOURNAL OF INSECT PHYSIOLOGY 2014; 69:35-40. [PMID: 24975799 DOI: 10.1016/j.jinsphys.2014.06.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 06/19/2014] [Accepted: 06/19/2014] [Indexed: 06/03/2023]
Abstract
Nutritional outcomes for animals are best understood when the intake of multiple nutrients are considered together. The requirements for protein and carbohydrate and the consequences for development, growth and fitness when confined to sub-optimal amounts and ratios of these nutrients are well known for many herbivorous insects. Water is also essential for life, and it is known that herbivorous insects will actively ingest free water, have physiological mechanisms controlling thirst, and suffer fitness consequences if water is excessive or deficient in the diet. As herbivorous insects are thought to obtain the majority of their water from foliage, which can vary in protein, carbohydrate and water content, we investigated if the Australian plague locust, Chortoicetes terminifera, can select among complementary foods to attain a target intake across these three nutrient dimensions. Locusts demonstrated selection behaviour for protein, carbohydrate and water by eating non-randomly from different combinations of complementary foods. A ratio of P:C:H2O of 1:1.13:13.2 or 1(P+C): 6.2 H2O was ingested. Given that locusts strongly regulate water intake, and its importance as an essential resource, we suggest future studies consider the single and interactive influences of water, protein and carbohydrate, when evaluating herbivorous insect host choice and foraging decisions.
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Affiliation(s)
- Fiona J Clissold
- School of Biological Sciences, A08, The University of Sydney, NSW 2006, Australia; Charles Perkins Centre, The University of Sydney, NSW 2006, Australia.
| | - Helena Kertesz
- School of Biological Sciences, A08, The University of Sydney, NSW 2006, Australia
| | - Amelia M Saul
- School of Biological Sciences, A08, The University of Sydney, NSW 2006, Australia
| | - Julia L Sheehan
- School of Biological Sciences, A08, The University of Sydney, NSW 2006, Australia
| | - Stephen J Simpson
- School of Biological Sciences, A08, The University of Sydney, NSW 2006, Australia; Charles Perkins Centre, The University of Sydney, NSW 2006, Australia
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Differing nutritional constraints of consumers across ecosystems. Oecologia 2014; 174:1367-76. [DOI: 10.1007/s00442-013-2860-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 12/11/2013] [Indexed: 11/26/2022]
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Clissold FJ, Coggan N, Simpson SJ. Insect herbivores can choose microclimates to achieve nutritional homeostasis. J Exp Biol 2013; 216:2089-96. [DOI: 10.1242/jeb.078782] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
The interaction between temperature and diet quality can affect the life-history of ectotherms. The rate and ratio at which protein and carbohydrate are obtained from food are an important aspect of diet quality, and insects have a well-developed capacity to adjust their feeding behaviour and postingestive physiology to regulate intake and allocation of these nutrients. If the supply of protein and carbohydrate varies with temperature (e.g. via effects on intake, digestion or metabolism), then herbivorous insects can use thermoregulatory behaviour to help achieve nutritional homeostasis. When fed the host grass Triticum aestivum, Locusta migratoria nymphs absorbed and allocated protein and carbohydrate to growth with the same efficiency at 38°C as at 32°C, however, at the higher temperature, they ingested more food. In contrast, when feeding on Themeda triandra, the nymphs absorbed carbohydrate with higher efficiency at 32°C and protein at 38°C. Using synthetic diets, we induced either a protein or a carbohydrate deficiency in experimental insects and showed that locusts placed in a thermal gradient following a meal of T. triandra selected 32°C when deprived of carbohydrate, and 38°C when protein-deficient. This capacity to use thermoregulatory behaviour to redress an imposed nutritional imbalance improved with experience of feeding on T. triandra. As predicted, locusts fed T. aestivum always chose higher temperatures, irrespective of nutritional state. Our results have consequences for understanding host plant choice by herbivores and interpreting the effects of changed environmental temperatures and microclimate on animal-plant interactions.
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