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Croll JC, van Kooten T. Accounting for temporal and individual variation in the estimation of Von Bertalanffy growth curves. Ecol Evol 2022; 12:e9619. [PMID: 36568868 PMCID: PMC9771669 DOI: 10.1002/ece3.9619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/30/2022] [Accepted: 07/04/2022] [Indexed: 12/24/2022] Open
Abstract
Growth and growth limitation are important indicators of density dependence and environmental limitation of populations. Estimating individual growth trajectories is therefore an important aspect of understanding and predicting the life history and dynamics of a population. Variation in individual growth trajectories arises due to variation in the environmental factors limiting individual growth. This environmental limitation can vary over time, between cohorts and between individuals within a cohort. For a complete and accurate understanding of individual growth in a population, it is important to include all these sources of variation. So far, statistical models only accounted for a subset of these factors or required an extensive growth history of individuals. Here, we present a novel model describing the growth curves of cohorts in a population. This model is derived from a stochastic form of the Von Bertalanffy growth equation describing individual growth. The model is specifically tailored for use on length-at-age data in which the growth trajectory of an individual is unknown and every individual is only measured once. The presented method can also be used if growth limitation differs strongly between age or length classes. We demonstrate the use of the model for length-at-age data of North Sea plaice (Pleuronectes platessa) from the last 30 years. Fitting this model to length-at-age data can provide new insights in the dynamics of the environmental factors limiting individual growth and provides a useful tool for ecological research and management.
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Affiliation(s)
- Jasper Cornelis Croll
- Institute for Biodiversity and Ecosystem DynamicsUniversity of AmsterdamAmsterdamThe Netherlands
| | - Tobias van Kooten
- Wageningen Marine ResearchWageningen University and ResearchWageningenThe Netherlands
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2
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Martin N, Hulbert AJ, Bicudo JEPW, Mitchell TW, Else PL. The adult lifespan of the female honey bee (Apis mellifera): Metabolic rate, AGE pigment and the effect of dietary fatty acids. Mech Ageing Dev 2021; 199:111562. [PMID: 34425137 DOI: 10.1016/j.mad.2021.111562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 07/30/2021] [Accepted: 08/17/2021] [Indexed: 01/23/2023]
Abstract
Female honey bees can be queens or workers and although genetically identical, workers have an adult lifespan of weeks while queens can live for years. The mechanisms underlying this extraordinary difference remain unknown. This study examines three potential explanations of the queen-worker lifespan difference. Metabolic rates were similar in age-matched queens and workers and thus are not an explanation. The accumulation of fluorescent AGE pigment has been successfully used as a good measure of cellular senescence in many species. Unlike other animals, AGE pigment level reduced during adult life of queens and workers. This unusual finding suggests female honey bees can either modify, or remove from their body, AGE pigment. Another queen-worker difference is that, as adults, workers eat pollen but queens do not. Pollen is a source of polyunsaturated fatty acids. Its consumption explains the queen-worker difference in membrane fat composition of female adult honey bees which has previously been suggested as a cause of the lifespan difference. We were able to produce "queen-worker" membrane differences in workers by manipulation of diet that did not change worker lifespan and we can, thus, also rule out pollen consumption by workers as an explanation of the dramatic queen-worker lifespan difference.
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Affiliation(s)
- N Martin
- School of Medicine, University of Wollongong, NSW, 2522, Australia; Illawarra Health and Medical Research Institute (IHMRI), Wollongong, NSW, 2522, Australia; School of Earth, Atmospheric and Life Sciences, University of Wollongong, NSW, 2522, Australia
| | - A J Hulbert
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, NSW, 2522, Australia
| | - J E P W Bicudo
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, NSW, 2522, Australia
| | - T W Mitchell
- School of Medicine, University of Wollongong, NSW, 2522, Australia; Illawarra Health and Medical Research Institute (IHMRI), Wollongong, NSW, 2522, Australia
| | - P L Else
- School of Medicine, University of Wollongong, NSW, 2522, Australia; Illawarra Health and Medical Research Institute (IHMRI), Wollongong, NSW, 2522, Australia.
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3
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Ellis LJA, Kissane S, Hoffman E, Valsami-Jones E, Brown JB, Colbourne JK, Lynch I. Multigenerational Exposure to Nano‐TiO
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Induces Ageing as a Stress Response Mitigated by Environmental Interactions. ADVANCED NANOBIOMED RESEARCH 2021. [DOI: 10.1002/anbr.202000083] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Laura-Jayne A. Ellis
- School of Geography, Earth and Environmental Sciences University of Birmingham Birmingham B15 2TT UK
| | - Stephen Kissane
- Environmental Transcriptomics Facility School of Biosciences University of Birmingham Birmingham B15 2TT UK
| | - Elijah Hoffman
- Genome Dynamics Department Life Sciences Division Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
| | - Eugenia Valsami-Jones
- School of Geography, Earth and Environmental Sciences University of Birmingham Birmingham B15 2TT UK
| | - James B. Brown
- Environmental Transcriptomics Facility School of Biosciences University of Birmingham Birmingham B15 2TT UK
- Genome Dynamics Department Life Sciences Division Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA
| | - John K. Colbourne
- Environmental Transcriptomics Facility School of Biosciences University of Birmingham Birmingham B15 2TT UK
| | - Iseult Lynch
- School of Geography, Earth and Environmental Sciences University of Birmingham Birmingham B15 2TT UK
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4
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Estévez Dimitrov R, Amendt J, Rothweiler F, Zehner R. Age determination of the adult blow fly Lucilia sericata (Diptera: Calliphoridae) through quantitative pteridine fluorescence analysis. Forensic Sci Med Pathol 2020; 16:641-648. [PMID: 32915388 PMCID: PMC7669773 DOI: 10.1007/s12024-020-00295-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2020] [Indexed: 02/02/2023]
Abstract
Determination of a minimal postmortem interval via age estimation of necrophagous diptera has been restricted to the juvenile stages and the time until emergence of the adult fly, i.e. up until 2-6 weeks depending on species and temperature. Age estimation of adult flies could extend this period by adding the age of the fly to the time needed for complete development. In this context pteridines are promising metabolites, as they accumulate in the eyes of flies with increasing age. We studied adults of the blow fly Lucilia sericata at constant temperatures of 16 °C and 25 °C up to an age of 25 days and estimated their pteridine levels by fluorescence spectroscopy. Age was given in accumulated degree days (ADD) across temperatures. Additionally, a mock case was set up to test the applicability of the method. Pteridine increases logarithmically with increasing ADD, but after 70-80 ADD the increase slows down and the curve approaches a maximum. Sex had a significant impact (p < 4.09 × 10-6) on pteridine fluorescence level, while body-size and head-width did not. The mock case demonstrated that a slight overestimation of the real age (in ADD) only occurred in two out of 30 samples. Age determination of L. sericata on the basis of pteridine levels seems to be limited to an age of about 70 ADD, but depending on the ambient temperature this could cover an extra amount of time of about 5-7 days after completion of the metamorphosis.
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Affiliation(s)
- Ronja Estévez Dimitrov
- Institute of Legal Medicine, University Hospital Frankfurt, Goethe-University, Kennedyallee 104, 60596, Frankfurt am Main, Germany.
| | - Jens Amendt
- Institute of Legal Medicine, University Hospital Frankfurt, Goethe-University, Kennedyallee 104, 60596, Frankfurt am Main, Germany
| | - Florian Rothweiler
- Institute of Medical Virology, University Hospital Frankfurt, Goethe-University, Paul-Ehrlich-Str.40, Frankfurt am Main, 60596, Germany
| | - Richard Zehner
- Institute of Legal Medicine, University Hospital Frankfurt, Goethe-University, Kennedyallee 104, 60596, Frankfurt am Main, Germany
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5
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Abstract
Invertebrates are becoming more popular and, as collections age, clients may seek veterinary intervention where the welfare of the animal must be considered. This article covers aging in many invertebrate species but with a focus on species likely to be seen in general practice. Supportive care may be an option to prolong life, but euthanasia must be considered for invertebrates with age-related unmanageable conditions.
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Affiliation(s)
- Sarah Pellett
- Animates Veterinary Clinic, 2 The Green, Thurlby, Lincolnshire PE10 0EB, UK.
| | - Michelle O'Brien
- Wildfowl & Wetlands Trust, Newgrounds Lane, Slimbridge, Gloucestershire GL2 7BT, UK
| | - Benjamin Kennedy
- Anton Vets, Anton Trading Estate, Anton Mill Road, Andover SP10 2NJ, UK
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6
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Křemenová J, Balvín O, Otti O, Pavonič M, Reinhardt K, Šimek Z, Bartonička T. Identification and age-dependence of pteridines in bed bugs (Cimex lectularius) and bat bugs (C. pipistrelli) using liquid chromatography-tandem mass spectrometry. Sci Rep 2020; 10:10146. [PMID: 32576867 PMCID: PMC7311437 DOI: 10.1038/s41598-020-66919-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 05/29/2020] [Indexed: 11/23/2022] Open
Abstract
Determining the age of free-living insects, particularly of blood-sucking species, is important for human health because such knowledge critically influences the estimates of biting frequency and vectoring ability. Genetic age determination is currently not available. Pteridines gradually accumulate in the eyes of insects and their concentrations is the prevailing method. Despite of their stability, published extractions differ considerably, including for standards, for mixtures of pteridines and even for light conditions. This methodological inconsistency among studies is likely to influence age estimates severely and to hamper their comparability. Therefore we reviewed methodological steps across 106 studies to identify methodological denominators and results across studies. Second, we experimentally test how different pteridines vary in their age calibration curves in, common bed (Cimex lectularius) and bat bugs (C. pipistrelli). Here we show that the accumulation of particular pteridines varied between a) different populations and b) rearing temperatures but not c) with the impact of light conditions during extraction or d) the type of blood consumed by the bugs. To optimize the extraction of pteridines and measuring concentrations, we recommend the simultaneous measurement of more than one standard and subsequently to select those that show consistent changes over time to differentiate among age cohorts.
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Affiliation(s)
- Jana Křemenová
- Masaryk University, Faculty of Sciences, Department of Botany and Zoology, Brno, 61137, Czech Republic.
| | - Ondřej Balvín
- Czech University of Life Sciences Prague, Faculty of Environmental Science, Department of Ecology, Prague, 16521, Czech Republic
| | - Oliver Otti
- Universität Bayreuth, Animal Ecology I, Animal Population Ecology, Bayreuth, 95440, Germany
| | - Michal Pavonič
- Masaryk University, Faculty of Sciences, Department of Botany and Zoology, Brno, 61137, Czech Republic
| | - Klaus Reinhardt
- Technische Universität Dresden, Department of Biology, Applied Zoology, Dresden, 01069, Germany
| | - Zdeněk Šimek
- Masaryk University, Research Centre for Toxic Compounds in the Environment, Brno, 62500, Czech Republic
| | - Tomáš Bartonička
- Masaryk University, Faculty of Sciences, Department of Botany and Zoology, Brno, 61137, Czech Republic
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7
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Ellis LJA, Kissane S, Hoffman E, Brown JB, Valsami-Jones E, Colbourne J, Lynch I. Multigenerational Exposures of Daphnia Magna to Pristine and Aged Silver Nanoparticles: Epigenetic Changes and Phenotypical Ageing Related Effects. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2000301. [PMID: 32338428 DOI: 10.1002/smll.202000301] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 06/11/2023]
Abstract
Engineered nanoparticles (NPs) undergo physical, chemical, and biological transformation after environmental release, resulting in different properties of the "aged" versus "pristine" forms. While many studies have investigated the ecotoxicological effects of silver (Ag) NPs, the majority focus on "pristine" Ag NPs in simple exposure media, rather than investigating realistic environmental exposure scenarios with transformed NPs. Here, the effects of "pristine" and "aged" Ag NPs are systematically evaluated with different surface coatings on Daphnia magna over four generations, comparing continuous exposure versus parental only exposure to assess recovery potential for three generations. Biological endpoints including survival, growth and reproduction and genetic effects associated with Ag NP exposure are investigated. Parental exposure to "pristine" Ag NPs has an inhibitory effect on reproduction, inducing expression of antioxidant stress related genes and reducing survival. Pristine Ag NPs also induce morphological changes including tail losses and lipid accumulation associated with aging phenotypes in the heart, abdomen, and abdominal claw. These effects are epigenetic remaining two generations post-maternal exposure (F2 and F3). Exposure to identical Ag NPs (same concentrations) aged for 6 months in environmentally realistic water containing natural organic matter shows considerably reduced toxicological effects in continuously exposed generations and to the recovery generations.
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Affiliation(s)
- Laura-Jayne A Ellis
- University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham, B15 2TT, UK
| | - Stephen Kissane
- University of Birmingham, School of Biosciences, Birmingham, B15 2TT, UK
| | - Elijah Hoffman
- Lawrence Berkeley National Laboratory, Genome Dynamics Department, Life Sciences Division, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - James B Brown
- University of Birmingham, School of Biosciences, Birmingham, B15 2TT, UK
- Lawrence Berkeley National Laboratory, Genome Dynamics Department, Life Sciences Division, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Eugenia Valsami-Jones
- University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham, B15 2TT, UK
| | - John Colbourne
- University of Birmingham, School of Biosciences, Birmingham, B15 2TT, UK
| | - Iseult Lynch
- University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham, B15 2TT, UK
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8
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Hartmann C, Heinze J, Bernadou A. Age-dependent changes in cuticular color and pteridine levels in a clonal ant. JOURNAL OF INSECT PHYSIOLOGY 2019; 118:103943. [PMID: 31518554 DOI: 10.1016/j.jinsphys.2019.103943] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 06/10/2023]
Abstract
Social insects are emerging models for studying aging and the longevity/fecundity trade-off. Research on the demography of colonies and populations are hampered by the lack of reliable age markers. Here we investigate the suitability of cuticular pigmentation and pteridine fluorescence for age grading individuals of the clonal ant Platythyrea punctata. We found that both traits varied with age. Cuticular color darkened with individual's age until 25-30 days after hatching. For pteridine fluorescence, we found that P. punctata workers show a decrease in head pteridine levels over time until 70-80 days of age. Together with other markers, such as age-based behavior, cuticular coloration and pteridine fluorescence may help to estimate the age structure of colonies.
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Affiliation(s)
- Clara Hartmann
- Zoology / Evolutionary Biology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Jürgen Heinze
- Zoology / Evolutionary Biology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
| | - Abel Bernadou
- Zoology / Evolutionary Biology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
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9
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Flores D, Miller AL, Showman A, Tobita C, Shimoda LMN, Sung C, Stokes AJ, Tomberlin JK, Carter DO, Turner H. Fluorescence Imaging of Posterior Spiracles from Second and Third Instars of Forensically Important Chrysomya rufifacies (Diptera: Calliphoridae) . J Forensic Sci 2016; 61:1578-1587. [PMID: 27706817 DOI: 10.1111/1556-4029.13189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 01/22/2016] [Accepted: 01/23/2016] [Indexed: 11/30/2022]
Abstract
Entomological protocols for aging blowfly (Diptera: Calliphoridae) larvae to estimate the time of colonization (TOC) are commonly used to assist in death investigations. While the methodologies for analyzing fly larvae differ, most rely on light microscopy, genetic analysis, or, more rarely, electron microscopy. This pilot study sought to improve resolution of larval stage in the forensically important blowfly Chrysomya rufifacies using high-content fluorescence microscopy and biochemical measures of developmental marker proteins. We established fixation and mounting protocols, defined a set of measurable morphometric criteria and captured developmental transitions of 2nd instar to 3rd instar using both fluorescence microscopy and anti-ecdysone receptor Western blot analysis. The data show that these instars can be distinguished on the basis of robust, nonbleaching, autofluorescence of larval posterior spiracles. High-content imaging techniques using confocal microscopy, combined with morphometric and biochemical techniques, may therefore aid forensic entomologists in estimating TOC.
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Affiliation(s)
- Danielle Flores
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816.,Graduate Program in Molecular Biosciences and Bioengineering, University of Hawaii at Mānoa, 1650 East-West Road, Honolulu, HI, 96816
| | - Amy L Miller
- Graduate Program in Molecular Biosciences and Bioengineering, University of Hawaii at Mānoa, 1650 East-West Road, Honolulu, HI, 96816
| | - Angelique Showman
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816.,Laboratory of Forensic Taphonomy, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
| | - Caitlyn Tobita
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
| | - Lori M N Shimoda
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
| | - Carl Sung
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
| | - Alexander J Stokes
- Laboratory of Experimental Medicine, John A. Burns School of Medicine, University of Hawaìi, 651 Ilalo Street, Honolulu, HI, 96813
| | | | - David O Carter
- Graduate Program in Molecular Biosciences and Bioengineering, University of Hawaii at Mānoa, 1650 East-West Road, Honolulu, HI, 96816
| | - Helen Turner
- Laboratory of Immunology and Signal Transduction, Division of Natural Sciences and Mathematics, Chaminade University, 3140 Waialae Avenue, Honolulu, HI, 96816
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10
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Rinkevich FD, Margotta JW, Pittman JM, Ottea JA, Healy KB. Pteridine levels and head weights are correlated with age and colony task in the honey bee, Apis mellifera. PeerJ 2016; 4:e2155. [PMID: 27413635 PMCID: PMC4933093 DOI: 10.7717/peerj.2155] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/31/2016] [Indexed: 11/20/2022] Open
Abstract
Background. The age of an insect strongly influences many aspects of behavior and reproduction. The interaction of age and behavior is epitomized in the temporal polyethism of honey bees in which young adult bees perform nurse and maintenance duties within the colony, while older bees forage for nectar and pollen. Task transition is dynamic and driven by colony needs. However, an abundance of precocious foragers or overage nurses may have detrimental effects on the colony. Additionally, honey bee age affects insecticide sensitivity. Therefore, determining the age of a set of individual honey bees would be an important measurement of colony health. Pteridines are purine-based pigment molecules found in many insect body parts. Pteridine levels correlate well with age, and wild caught insects may be accurately aged by measuring pteridine levels. The relationship between pteridines and age varies with a number of internal and external factors among many species. Thus far, no studies have investigated the relationship of pteridines with age in honey bees. Methods. We established single-cohort colonies to obtain age-matched nurse and forager bees. Bees of known ages were also sampled from colonies with normal demographics. Nurses and foragers were collected every 3-5 days for up to 42 days. Heads were removed and weighed before pteridines were purified and analyzed using previously established fluorometric methods. Results. Our analysis showed that pteridine levels significantly increased with age in a linear manner in both single cohort colonies and colonies with normal demography. Pteridine levels were higher in foragers than nurses of the same age in bees from single cohort colonies. Head weight significantly increased with age until approximately 28-days of age and then declined for both nurse and forager bees in single cohort colonies. A similar pattern of head weight in bees from colonies with normal demography was observed but head weight was highest in 8-day old nurse bees and there was no relationship of head weight with age of foragers. Discussion. Although the relationship between pteridine levels and age was significant, variation in the data yielded a +4-day range in age estimation. This allows an unambiguous method to determine whether a bee may be a young nurse or old forager in colonies with altered demographics as in the case of single cohort colonies. Pteridine levels in bees do not correlate with age as well as in other insects. However, most studies used insects reared under tightly controlled laboratory conditions, while we used free-living bees. The dynamics of head weight change with age is likely to be due to growth and atrophy of the hypopharyngeal glands. Taken together, these methods represent a useful tool for assessing the age of an insect. Future studies utilizing these methods will provide a more holistic view of colony health.
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Affiliation(s)
- Frank D Rinkevich
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States; Honey Bee Breeding, Genetics, and Physiology Laboratory, USDA-ARS, Baton Rouge, LA, United States
| | - Joseph W Margotta
- Department of Entomology, Louisiana State University Agricultural Center , Baton Rouge , LA , United States
| | - Jean M Pittman
- Department of Entomology, Louisiana State University Agricultural Center , Baton Rouge , LA , United States
| | - James A Ottea
- Department of Entomology, Louisiana State University Agricultural Center , Baton Rouge , LA , United States
| | - Kristen B Healy
- Department of Entomology, Louisiana State University Agricultural Center , Baton Rouge , LA , United States
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11
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Nansen C, Ribeiro LP, Dadour I, Roberts JD. Detection of temporal changes in insect body reflectance in response to killing agents. PLoS One 2015; 10:e0124866. [PMID: 25923362 PMCID: PMC4414589 DOI: 10.1371/journal.pone.0124866] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 03/17/2015] [Indexed: 01/15/2023] Open
Abstract
Computer vision and reflectance-based analyses are becoming increasingly important methods to quantify and characterize phenotypic responses by whole organisms to environmental factors. Here, we present the first study of how a non-destructive and completely non-invasive method, body reflectance profiling, can be used to detect and time stress responses in adult beetles. Based on high-resolution hyperspectral imaging, we acquired time series of average reflectance profiles (70 spectral bands from 434-876 nm) from adults in two beetle species, maize weevils (Sitophilus zeamais) and larger black flour beetles (Cynaus angustus). For each species, we acquired reflectance data from untreated controls and from individuals exposed continuously to killing agents (an insecticidal plant extract applied to maize kernels or entomopathogenic nematodes applied to soil applied at levels leading to ≈100% mortality). In maize weevils (exposed to hexanic plant extract), there was no significant effect of the on reflectance profiles acquired from adult beetles after 0 and 12 hours of exposure, but a significant treatment response in spectral bands from 434 to 550 nm was detected after 36 to 144 hours of exposure. In larger black flour beetles, there was no significant effect of exposure to entomopathogenic nematodes after 0 to 26 hours of exposure, but a significant response in spectral bands from 434-480 nm was detected after 45 and 69 hours of exposure. Spectral bands were used to develop reflectance-based classification models for each species, and independent validation of classification algorithms showed sensitivity (ability to positively detect terminal stress in beetles) and specificity (ability to positively detect healthy beetles) of about 90%. Significant changes in body reflectance occurred at exposure times, which coincided with published exposure times and known physiological responses to each killing agent. The results from this study underscore the potential of hyperspectral imaging as an approach to non-destructively and non-invasively quantify stress detection in insects and other animals.
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Affiliation(s)
- Christian Nansen
- Department of Entomology and Nematology, University of California Davis, Davis, California, United States of America
- * E-mail:
| | - Leandro Prado Ribeiro
- Department of Entomology and Acarology, University of São Paulo, Piracicaba, São Paulo, Brazil
| | - Ian Dadour
- Centre for Forensic Science, The University of Western Australia, Perth, Western Australia, Australia
| | - John Dale Roberts
- School of Animal Biology and Centre for Evolutionary Biology and Centre of Excellence in Natural Resource Management, The University of Western Australia, Albany, Western Australia, Australia
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