scholarly journals The importance of environmental microbes for Drosophila melanogaster during seasonal macronutrient variability

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lucy Rebecca Davies ◽  
Volker Loeschcke ◽  
Mads F. Schou ◽  
Andreas Schramm ◽  
Torsten N. Kristensen
Keyword(s):  
Life History ◽  
Microbial Community ◽  
Stress Resistance ◽  
Life History Traits ◽  
Food Sources ◽  
Temperate Climate ◽  
Natural Food ◽  
Fitness Components ◽  
Macronutrient Composition ◽  
Nutritional Environment

AbstractExperiments manipulating the nutritional environment and the associated microbiome of animals have demonstrated their importance for key fitness components. However, there is little information on how macronutrient composition and bacterial communities in natural food sources vary across seasons in nature and on how these factors affect the fitness components of insects. In this study, diet samples from an orchard compost heap, which is a natural habitat for many Drosophila species and other arthropods, were collected over 9 months covering all seasons in a temperate climate. We developed D. melanogaster on diet samples and investigated stress resistance and life-history traits as well as the microbial community of flies and compost. Nutrient and microbial community analysis of the diet samples showed marked differences in macronutrient composition and microbial community across seasons. However, except for the duration of development on these diet samples and Critical Thermal maximum, fly stress resistance and life-history traits were unaffected. The resulting differences in the fly microbial community were also more stable and less diverse than the microbial community of the diet samples. Our study suggests that when D. melanogaster are exposed to a vastly varying nutritional environment with a rich, diverse microbial community, the detrimental consequences of an unfavourable macronutrient composition are offset by the complex interactions between microbes and nutrients.

scholarly journals Interactions with a Complex Microbiota Mediate a Trade-Off between the Host Development Rate and Heat Stress Resistance

2020 ◽  
Vol 8 (11) ◽  
pp. 1781
Author(s):  
Samuel Slowinski ◽  
Isabella Ramirez ◽  
Vivek Narayan ◽  
Medha Somayaji ◽  
Maya Para ◽  
...  
Keyword(s):  
Life History ◽  
Heat Stress ◽  
Stress Resistance ◽  
Life History Traits ◽  
Soil Microbes ◽  
Development Rate ◽  
Heat Stress Resistance ◽  
Host Life ◽  
Host Development ◽  
Resistance To Heat

Animals and plants host diverse communities of microorganisms, and these microbiotas have been shown to influence host life history traits. Much has been said about the benefits that host-associated microbiotas bestow on the host. However, life history traits often demonstrate tradeoffs among one another. Raising Caenorhabditis elegans nematodes in compost microcosms emulating their natural environment, we examined how complex microbiotas affect host life history traits. We show that soil microbes usually increase the host development rate but decrease host resistance to heat stress, suggesting that interactions with complex microbiotas may mediate a tradeoff between host development and stress resistance. What element in these interactions is responsible for these effects is yet unknown, but experiments with live versus dead bacteria suggest that such effects may depend on bacterially provided signals.

Life-History Traits of a Subtropical Cerambycid Beetle, Ropica honesta (Coleoptera: Cerambycidae)

2019 ◽  
Vol 48 (4) ◽  
pp. 923-928
Author(s):  
Keisuke Nagamine ◽  
Yoshiyasu Kusakabe ◽  
Takashi Tsuchida ◽  
Yuya Horiuchi ◽  
Yuya Nemoto ◽  
...  
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Local Population ◽  
Total Duration ◽  
Threshold Temperature ◽  
Thermal Constant ◽  
Natural Food ◽  
Larval Food ◽  
Developmental Threshold ◽  
Significant Difference

Abstract Ropica honesta Pascoe is a small-sized cerambycid that has been recorded in tropical to subtropical Asia. In this study, life-history traits were examined for a local population collected from Iriomote Island (24.3°N, 123.8°E), Okinawa, Japan, by rearing insects on artificial diet as larval food. The egg period was 5.9 ± 0.3 d at 25°C. There was no significant difference in the duration of the larval, pupal, and adult preoviposition periods between long-day (14:10 [L:D]) and short-day (12:12 [L:D]) photoperiods at both 20 and 25°C. These periods at 25°C (14:10 [L:D]) were 28.5 ± 1.4, 8.4 ± 0.5, and 9.6 ± 1.9 d (mean ± SD), respectively. The relationship between the developmental rate and temperature followed the law of total effective temperature; thus, the developmental threshold temperature and thermal constant were estimated based on these data. Together with the finding that R. honesta may not have diapause in the egg stage, it is suggested that this beetle does not have diapause in the life cycle. Furthermore, when larvae were reared on natural food (dead twigs of hardwoods) adults emerged from the twigs 47.6 ± 2.9 d after oviposition, and this value was close to the total duration of the egg to pupal periods. Together with the data for annual temperature of the habitat and the fact that food resources for the species (dead twigs and leaves of hardwoods) are available throughout the year, we conclude that R. honesta develops and reproduces all year round, with five generations at maximum.

scholarly journals Genetic variation and correlations of life-history traits in gypsy moths (Lymantria dispar L.) from two populations in Serbia

2008 ◽  
Vol 60 (4) ◽  
pp. 619-627 ◽  
Author(s):  
Jelica Lazarevic ◽  
Vera Nenadovic ◽  
Milena Jankovic-Tomanic ◽  
S. Milanovic
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Individual Performance ◽  
Medium Density ◽  
Delayed Effects ◽  
Gypsy Moths ◽  
Development Duration ◽  
Egg Provisioning ◽  
Nutritional Environment ◽  
Density Population

Periodic fluctuations in density impose different selection pressures on populations of outbreaking Lepidoptera due to changes in their nutritional environment. The maternal effects hypothesis of insect outbreak predicts the transmission of this nutritional "information" to subsequent generations and alterations in offspring life-history traits. To test for these time-delayed effects of the parental generation, we compared life-history traits and their variation and covariation among laboratory-reared gypsy moths hatched from egg masses collected from low- and medium-density populations. Decreased individual performance was recorded in offspring from the medium-density population, indicating reduced egg provisioning under crowding conditions. Genetic variance and covariance were also shown to be sensitive to density of the parental generation. In gypsy moths from the medium-density population, quantitative genetic analysis revealed significantly higher broad-sense heritabilities for development duration traits and demonstrated a trade-off between development duration and body size.

scholarly journals Consequences of combining life-history traits with sex-specific differences

2020 ◽  
Author(s):  
Vandana Revathi Venkateswaran ◽  
Olivia Roth ◽  
Chaitanya S. Gokhale
Keyword(s):  
Life History ◽  
Sexual Dimorphism ◽  
Reproductive Success ◽  
Parental Investment ◽  
Life History Traits ◽  
Life History Strategies ◽  
Lifetime Reproductive Success ◽  
Fitness Components ◽  
Adult Sex Ratio ◽  
Males And Females

Males and females evolved distinct life-history strategies, reflected in diverse life-history traits, summarized as sexual dimorphism. Life-history traits are highly interlinked. The sex that allocates more resources towards offspring is expected to increase its life span, and this might require an efficient immune system. However, the other sex might allocate its resources towards ornamentation, and this might have immunosuppressive effects. Activity of immune response may not be specific to the sex that produces the eggs but could correlate with the amount of parental investment given. Informed by experimental data, we designed a theoretical framework that combines multiple life-history traits. We disentangled sex-biased life-history strategies from a particular sex to include species with reversed sex-roles, and male parental investment. We computed the lifetime reproductive success from the fitness components arising from diverse sex-biased life-history traits, and observed a strong bias in adult sex ratio depending on sex-specific resource allocation towards life-history traits. Overall, our work provides a generalized method to combine various life-history traits with sex-specific differences to calculate the lifetime reproductive success. This was used to explain certain empirical observations as a consequence of sexual dimorphism in life-history traits.

scholarly journals The gut bacterial community affects immunity but not metabolism in a specialist herbivorous butterfly

2020 ◽  
Author(s):  
Anne Duplouy ◽  
Guillaume Minard ◽  
Marjo Saastamoinen
Keyword(s):  
Life History ◽  
Microbial Community ◽  
Life History Traits ◽  
Plantago Lanceolata ◽  
Experimental Manipulation ◽  
Host Immune System ◽  
Immune Gene ◽  
Growth And Survival ◽  
Bacterial Microbiota ◽  
Gut Microbial Community

Abstract Background Many plant tissues are not resources of optimal nutritious value. They often lack essential nutritive elements and may contain a range of secondary toxic compounds. As nutritional imbalance in food intake may affect the performances of herbivores, the latter have evolved a variety of physiological mechanisms to cope with the challenges of digesting their plant-based diet. Some of these strategies involve living in association with symbiotic microbes that promote the digestion and detoxification of plant compounds, or supply their host with essential nutrients missing from the plant diet. In Lepidoptera, a growing body of evidence has, however, recently challenged the idea that herbivores are nutritionally dependent on their gut microbial community. It is suggested that many of the herbivorous species may not host a resident microbial community, but rather a transient one, acquired from their environment and diet. Results By coupling comparative meta-barcoding, immune gene expression and metabolomics analyses with experimental manipulation of the gut microbial community of pre-diapause larvae of the Glanville fritillary butterfly ( Melitaea cinxia, L.), we tested whether the larvae host a gut microbial community that supports growth and survival, and modulates metabolism and immunity during the early stages of development. We successfully altered this microbiota through antibiotic treatments, and consecutively restored it through fecal transplants from conspecifics. Under laboratory conditions, Firmicutes dominated the bacterial microbiota associated with the gut and frass of non-treated larvae, even though these Gram-positive bacteria were not found in association with the host plant, Plantago lanceolata . Furthermore our study suggests that the microbiota is involved in the up-regulation of an antimicrobial peptide, but did not affect the life-history traits or the metabolism of early instars larvae. Conclusions This study confirms the poor impact of the microbiota on diverse life history traits of yet another Lepidoptera species. However, it also suggests that potential eco-evolutionary host-symbiont strategies that take place in the gut of herbivorous butterfly hosts might have been disregarded, particularly how the microbiota may affect the host immune system homeostasis.

Prey tell: what quillback rockfish early life history traits reveal about their survival in encounters with juvenile coho salmon

2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Direct Evidence ◽  
Coho Salmon ◽  
Larval Fish ◽  
Early Life History ◽  
In The Wild ◽  
Otolith Microstructure Analysis ◽  
Pelagic Juvenile

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.

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