Editorial

5 pages, 192 KiB

Open AccessEditorial

Mechanisms of Nutritional Resource Exploitation by Insects

by Sara D. Leonhardt, Mathieu Lihoreau and Johannes Spaethe

Insects 2020, 11(9), 570; https://doi.org/10.3390/insects11090570 - 25 Aug 2020

Cited by 8 | Viewed by 2782

Insects have evolved an extraordinary range of nutritional adaptations to exploit other animals, plants, bacteria, fungi and soils as resources in terrestrial and aquatic environments. This special issue provides some new insights into the mechanisms underlying these adaptations. Contributions comprise lab and field [...] Read more.

Insects have evolved an extraordinary range of nutritional adaptations to exploit other animals, plants, bacteria, fungi and soils as resources in terrestrial and aquatic environments. This special issue provides some new insights into the mechanisms underlying these adaptations. Contributions comprise lab and field studies investigating the chemical, physiological, cognitive and behavioral mechanisms that enable resource exploitation and nutrient intake regulation in insects. The collection of papers highlights the need for more studies on the comparative sensory ecology, underlying nutritional quality assessment, cue perception and decision making to fully understand how insects adjust resource selection and exploitation in response to environmental heterogeneity and variability. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

Research

Jump to: Editorial, Review, Other

16 pages, 2695 KiB

Open AccessArticle

Asteraceae Paradox: Chemical and Mechanical Protection of Taraxacum Pollen

by Maryse Vanderplanck, Hélène Gilles, Denis Nonclercq, Pierre Duez and Pascal Gerbaux

Insects 2020, 11(5), 304; https://doi.org/10.3390/insects11050304 - 14 May 2020

Cited by 34 | Viewed by 4767

Abstract

Excessive pollen harvesting by bees can compromise the reproductive success of plants. Plants have therefore evolved different morphological structures and floral cues to narrow the spectrum of pollen feeding visitors. Among “filtering” mechanisms, the chemical and mechanical protection of pollen might shape bee-flower [...] Read more.

Excessive pollen harvesting by bees can compromise the reproductive success of plants. Plants have therefore evolved different morphological structures and floral cues to narrow the spectrum of pollen feeding visitors. Among “filtering” mechanisms, the chemical and mechanical protection of pollen might shape bee-flower interactions and restrict pollen exploitation to a specific suite of visitors such as observed in Asteraceae. Asteraceae pollen is indeed only occasionally exploited by generalist bee species but plentifully foraged by specialist ones (i.e., Asteraceae paradox). During our bioassays, we observed that micro-colonies of generalist bumblebee (Bombus terrestris L.) feeding on Taraxacum pollen (Asteraceae) reduced their pollen collection and offspring production. Bees also experienced physiological effects of possible defenses in the form of digestive damage. Overall, our results suggest the existence of an effective chemical defense in Asteraceae pollen, while the hypothesis of a mechanical defense appeared more unlikely. Pre- and post-ingestive effects of such chemical defenses (i.e., nutrient deficit or presence of toxic compounds), as well as their role in the shaping of bee-flower interactions, are discussed. Our results strongly suggest that pollen chemical traits may act as drivers of plant selection by bees and partly explain why Asteraceae pollen is rare in generalist bee diets. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Figure 1

11 pages, 1294 KiB

Open AccessArticle

Adding Amino Acids to a Sucrose Diet Is Not Sufficient to Support Longevity of Adult Bumble Bees

by Nils Grund-Mueller, Fabian A. Ruedenauer, Johannes Spaethe and Sara D. Leonhardt

Insects 2020, 11(4), 247; https://doi.org/10.3390/insects11040247 - 15 Apr 2020

Cited by 10 | Viewed by 2951

Abstract

Dietary macro-nutrients (i.e., carbohydrates, protein, and fat) are important for bee larval development and, thus, colony health and fitness. To which extent different diets (varying in macro-nutrient composition) affect adult bees and whether they can thrive on nectar as the sole amino acid [...] Read more.

Dietary macro-nutrients (i.e., carbohydrates, protein, and fat) are important for bee larval development and, thus, colony health and fitness. To which extent different diets (varying in macro-nutrient composition) affect adult bees and whether they can thrive on nectar as the sole amino acid source has, however, been little investigated. We investigated how diets varying in protein concentration and overall nutrient composition affected consumption, longevity, and breeding behavior of the buff-tailed bumble bee, Bombus terrestris (Hymenoptera: Apidae). Queenless micro-colonies were fed either natural nutrient sources (pollen), nearly pure protein (i.e., the milk protein casein), or sucrose solutions with low and with high essential amino acid content in concentrations as can be found in nectar. We observed micro-colonies for 110 days. We found that longevity was highest for pure pollen and lowest for pure sucrose solution and sucrose solution supplemented with amino acids in concentrations as found in the nectar of several plant species. Adding higher concentrations of amino acids to sucrose solution did only slightly increase longevity compared to sucrose alone. Consequently, sucrose solution with the applied concentrations and proportions of amino acids or other protein sources (e.g., casein) alone did not meet the nutritional needs of healthy adult bumble bees. In fact, longevity was highest and reproduction only successful in micro-colonies fed pollen. These results indicate that, in addition to carbohydrates and protein, adult bumble bees, like larvae, need further nutrients (e.g., lipids and micro-nutrients) for their well-being. An appropriate nutritional composition seemed to be best provided by floral pollen, suggesting that pollen is an essential dietary component not only for larvae but also for adult bees. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Figure 1

14 pages, 1706 KiB

Open AccessArticle

Pollen Protein: Lipid Macronutrient Ratios May Guide Broad Patterns of Bee Species Floral Preferences

by Anthony D. Vaudo, John F. Tooker, Harland M. Patch, David J. Biddinger, Michael Coccia, Makaylee K. Crone, Mark Fiely, Jacob S. Francis, Heather M. Hines, Mackenzie Hodges, Stephanie W. Jackson, Denis Michez, Junpeng Mu, Laura Russo, Maliheh Safari, Erin D. Treanore, Maryse Vanderplanck, Eric Yip, Anne S. Leonard and Christina M. Grozinger

Insects 2020, 11(2), 132; https://doi.org/10.3390/insects11020132 - 18 Feb 2020

Cited by 126 | Viewed by 14333

Abstract

Pollinator nutritional ecology provides insights into plant–pollinator interactions, coevolution, and the restoration of declining pollinator populations. Bees obtain their protein and lipid nutrient intake from pollen, which is essential for larval growth and development as well as adult health and reproduction. Our previous [...] Read more.

Pollinator nutritional ecology provides insights into plant–pollinator interactions, coevolution, and the restoration of declining pollinator populations. Bees obtain their protein and lipid nutrient intake from pollen, which is essential for larval growth and development as well as adult health and reproduction. Our previous research revealed that pollen protein to lipid ratios (P:L) shape bumble bee foraging preferences among pollen host-plant species, and these preferred ratios link to bumble bee colony health and fitness. Yet, we are still in the early stages of integrating data on P:L ratios across plant and bee species. Here, using a standard laboratory protocol, we present over 80 plant species’ protein and lipid concentrations and P:L values, and we evaluate the P:L ratios of pollen collected by three bee species. We discuss the general phylogenetic, phenotypic, behavioral, and ecological trends observed in these P:L ratios that may drive plant–pollinator interactions; we also present future research questions to further strengthen the field of pollination nutritional ecology. This dataset provides a foundation for researchers studying the nutritional drivers of plant–pollinator interactions as well as for stakeholders developing planting schemes to best support pollinators. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Figure 1

19 pages, 1505 KiB

Open AccessArticle

Floral Species Richness Correlates with Changes in the Nutritional Quality of Larval Diets in a Stingless Bee

by Moritz Trinkl, Benjamin F. Kaluza, Helen Wallace, Tim A. Heard, Alexander Keller and Sara D. Leonhardt

Insects 2020, 11(2), 125; https://doi.org/10.3390/insects11020125 - 15 Feb 2020

Cited by 28 | Viewed by 5577

Abstract

Bees need food of appropriate nutritional quality to maintain their metabolic functions. They largely obtain all required nutrients from floral resources, i.e., pollen and nectar. However, the diversity, composition and nutritional quality of floral resources varies with the surrounding environment and can be [...] Read more.

Bees need food of appropriate nutritional quality to maintain their metabolic functions. They largely obtain all required nutrients from floral resources, i.e., pollen and nectar. However, the diversity, composition and nutritional quality of floral resources varies with the surrounding environment and can be strongly altered in human-impacted habitats. We investigated whether differences in plant species richness as found in the surrounding environment correlated with variation in the floral diversity and nutritional quality of larval provisions (i.e., mixtures of pollen, nectar and salivary secretions) composed by the mass-provisioning stingless bee Tetragonula carbonaria (Apidae: Meliponini). We found that the floral diversity of larval provisions increased with increasing plant species richness. The sucrose and fat (total fatty acid) content and the proportion and concentration of the omega-6 fatty acid linoleic acid decreased, whereas the proportion of the omega-3 fatty acid linolenic acid increased with increasing plant species richness. Protein (total amino acid) content and amino acid composition did not change. The protein to fat (P:F) ratio, known to affect bee foraging, increased on average by more than 40% from plantations to forests and gardens, while the omega-6:3 ratio, known to negatively affect cognitive performance, decreased with increasing plant species richness. Our results suggest that plant species richness may support T. carbonaria colonies by providing not only a continuous resource supply (as shown in a previous study), but also floral resources of high nutritional quality. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Graphical abstract

15 pages, 923 KiB

Open AccessArticle

Inter-Individual Nectar Chemistry Changes of Field Scabious, Knautia arvensis

by Christine Venjakob, Sara Leonhardt and Alexandra-Maria Klein

Insects 2020, 11(2), 75; https://doi.org/10.3390/insects11020075 - 22 Jan 2020

Cited by 13 | Viewed by 3298

Abstract

Nectar is crucial to maintain plant-pollinator mutualism. Nectar quality (nutritional composition) can vary strongly between individuals of the same plant species. The factors driving such inter-individual variation have however not been investigated closer. We investigated nectar quality of field scabious, Knautia arvensis in [...] Read more.

Nectar is crucial to maintain plant-pollinator mutualism. Nectar quality (nutritional composition) can vary strongly between individuals of the same plant species. The factors driving such inter-individual variation have however not been investigated closer. We investigated nectar quality of field scabious, Knautia arvensis in different grassland plant communities varying in species composition and richness to assess whether nectar quality can be affected by the surrounding plant community. We analyzed (with high performance liquid chromatography) the content of carbohydrates, overall amino acids, and essential amino acids. Amino acid and carbohydrate concentrations and proportions varied among plant individuals and with the surrounding plant community but were not related to the surrounding plant species richness. Total and individual carbohydrate concentrations were lowest, while proportions of the essential amino acids, valine, isoleucine, leucine (all phagostimulatory), and lysine were highest in plant species communities of the highest diversity. Our results show that K. arvensis nectar chemistry varies with the composition of the surrounding plant community, which may alter the taste and nutritional value and thus affect the plant’s visitor spectrum and visitation rate. However, the strong inter-individual variation in nectar quality requires additional studies (e.g., in semi-field studies) to disentangle different biotic and abiotic factors contributing to inter-individual nectar chemistry in a plant-community context. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Figure 1

10 pages, 807 KiB

Open AccessArticle

Warming Increases Pollen Lipid Concentration in an Invasive Thistle, with Minor Effects on the Associated Floral-Visitor Community

by Laura Russo, Joseph Keller, Anthony D. Vaudo, Christina M. Grozinger and Katriona Shea

Insects 2020, 11(1), 20; https://doi.org/10.3390/insects11010020 - 25 Dec 2019

Cited by 10 | Viewed by 4877

Abstract

Climate warming is likely to change the ways in which plants interact with their insect mutualists, for example through changes in phytochemistry. In particular, this may have implications for the ways in which we manage noxious weeds, which may spread more quickly if [...] Read more.

Climate warming is likely to change the ways in which plants interact with their insect mutualists, for example through changes in phytochemistry. In particular, this may have implications for the ways in which we manage noxious weeds, which may spread more quickly if they experience stronger mutualistic interactions. We grew the invasive nodding thistle, Carduus nutans, in two experimental treatments in the field: either passively warmed with open top chambers or at ambient temperatures. We collected pollen from thistles in each treatment and analysed the total protein, lipid, and carbohydrate content. We observed no difference in the pollen protein or carbohydrate content, but the total lipid content of the pollen was significantly higher in warmed plants. We conducted a total of 12.75 h of observations of putatively mutualistic, flower-visiting insects. In addition, we spent 4.17 h collecting bees that visited thistle inflorescences in the treatments, allowing us to identify them to species. We found a significant increase in the abundance of flower-visiting insects in the observations, but not bee abundance in collections. In addition, there was no treatment effect on the number of flower-visiting morphotypes in the observations, or bee species richness in the collections. However, a nonparametric test did identify a significant effect of warming on the composition of flower-visiting morphotypes in observations and bee species in collections. Overall, the warming treatment significantly increased lipid content of the pollen, but had relatively weak effects on insect visitation patterns. However, these effects may be amplified at larger spatial and temporal scales or higher temperatures. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Figure 1

14 pages, 2013 KiB

Open AccessArticle

Insulin Receptor Substrate Gene Knockdown Accelerates Behavioural Maturation and Shortens Lifespan in Honeybee Workers

by Kate E. Ihle, Navdeep S. Mutti, Osman Kaftanoglu and Gro V. Amdam

Insects 2019, 10(11), 390; https://doi.org/10.3390/insects10110390 - 05 Nov 2019

Cited by 12 | Viewed by 3366

Abstract

In animals, dietary restriction or suppression of genes involved in nutrient sensing tends to increase lifespan. In contrast, food restriction in honeybees (Apis mellifera) shortens lifespan by accelerating a behavioural maturation program that culminates in leaving the nest as a forager. [...] Read more.

In animals, dietary restriction or suppression of genes involved in nutrient sensing tends to increase lifespan. In contrast, food restriction in honeybees (Apis mellifera) shortens lifespan by accelerating a behavioural maturation program that culminates in leaving the nest as a forager. Foraging is metabolically demanding and risky, and foragers experience increased rates of aging and mortality. Food-deprived worker bees forage at younger ages and are expected to live shorter lives. We tested whether suppression of a molecular nutrient sensing pathway is sufficient to accelerate the behavioural transition to foraging and shorten worker life. To achieve this, we reduced expression of the insulin receptor substrate (irs) gene via RNA interference in two selected lines of honeybees used to control for behavioural and genetic variation. irs encodes a membrane-associated protein in the insulin/insulin-like signalling (IIS) pathway that is central to nutrient sensing in animals. We measured foraging onset and lifespan and found that suppression of irs reduced worker bee lifespan in both genotypes, and that this effect was largely driven by an earlier onset of foraging behaviour in a genotype-conditional manner. Our results provide the first direct evidence that an IIS pathway gene influences behavioural maturation and lifespan in honeybees and highlight the importance of considering social environments and behaviours when investigating the regulation of aging and lifespan in social animals. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Figure 1

10 pages, 842 KiB

Open AccessArticle

The Effect of Diet on the Composition and Stability of Proteins Secreted by Honey Bees in Honey

by Oleg Lewkowski, Carmen I. Mureșan, Dirk Dobritzsch, Matthew Fuszard and Silvio Erler

Insects 2019, 10(9), 282; https://doi.org/10.3390/insects10090282 - 02 Sep 2019

Cited by 20 | Viewed by 4804

Abstract

Honey proteins are essential bee nutrients and antimicrobials that protect honey from microbial spoilage. The majority of the honey proteome includes bee-secreted peptides and proteins, produced in specialised glands; however, bees need to forage actively for nitrogen sources and other basic elements of [...] Read more.

Honey proteins are essential bee nutrients and antimicrobials that protect honey from microbial spoilage. The majority of the honey proteome includes bee-secreted peptides and proteins, produced in specialised glands; however, bees need to forage actively for nitrogen sources and other basic elements of protein synthesis. Nectar and pollen of different origins can vary significantly in their nutritional composition and other compounds such as plant secondary metabolites. Worker bees producing and ripening honey from nectar might therefore need to adjust protein secretions depending on the quality and specific contents of the starting material. Here, we assessed the impact of different food sources (sugar solutions with different additives) on honey proteome composition and stability, using controlled cage experiments. Honey-like products generated from sugar solution with or without additional protein, or plant secondary metabolites, differed neither in protein quality nor in protein quantity among samples. Storage for 4 weeks prevented protein degradation in most cases, without differences between food sources. The honey-like product proteome included several major royal jelly proteins, alpha-glucosidase and glucose oxidase. As none of the feeding regimes resulted in different protein profiles, we can conclude that worker bees may secrete a constant amount of each bee-specific protein into honey to preserve this highly valuable hive product. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Graphical abstract

Review

Jump to: Editorial, Research, Other

14 pages, 2751 KiB

Open AccessReview

Using Nutritional Geometry to Explore How Social Insects Navigate Nutritional Landscapes

by Antonin J. J. Crumière, Calum J. Stephenson, Manuel Nagel and Jonathan Z. Shik

Insects 2020, 11(1), 53; https://doi.org/10.3390/insects11010053 - 15 Jan 2020

Cited by 10 | Viewed by 6061

Abstract

Insects face many cognitive challenges as they navigate nutritional landscapes that comprise their foraging environments with potential food items. The emerging field of nutritional geometry (NG) can help visualize these challenges, as well as the foraging solutions exhibited by insects. Social insect species [...] Read more.

Insects face many cognitive challenges as they navigate nutritional landscapes that comprise their foraging environments with potential food items. The emerging field of nutritional geometry (NG) can help visualize these challenges, as well as the foraging solutions exhibited by insects. Social insect species must also make these decisions while integrating social information (e.g., provisioning kin) and/or offsetting nutrients provisioned to, or received from unrelated mutualists. In this review, we extend the logic of NG to make predictions about how cognitive challenges ramify across these social dimensions. Focusing on ants, we outline NG predictions in terms of fundamental and realized nutritional niches, considering when ants interact with related nestmates and unrelated bacterial, fungal, plant, and insect mutualists. The nutritional landscape framework we propose provides new avenues for hypothesis testing and for integrating cognition research with broader eco-evolutionary principles. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Figure 1

Other

Jump to: Editorial, Research, Review

6 pages, 1112 KiB

Open AccessOpinion

Open Data for Open Questions in Comparative Nutrition

by Juliano Morimoto and Mathieu Lihoreau

Insects 2020, 11(4), 236; https://doi.org/10.3390/insects11040236 - 09 Apr 2020

Cited by 6 | Viewed by 2542

Abstract

Achieving a better understanding of the consequences of nutrition to animal fitness and human health is a major challenge of our century. Nutritional ecology studies increasingly use nutritional landscapes to map the complex interacting effects of nutrient intake on animal performances, in a [...] Read more.

Achieving a better understanding of the consequences of nutrition to animal fitness and human health is a major challenge of our century. Nutritional ecology studies increasingly use nutritional landscapes to map the complex interacting effects of nutrient intake on animal performances, in a wide range of species and ecological contexts. Here, we argue that opening access to these hard-to-obtain, yet considerably insightful, data is fundamental to develop a comparative framework for nutrition research and offer new quantitative means to address open questions about the ecology and evolution of nutritional processes. Full article

(This article belongs to the Special Issue Mechanisms of Nutritional Resource Exploitation by Insects)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Mechanisms of Nutritional Resource Exploitation by Insects

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (11 papers)

Editorial

Research

Review

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI