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Mendoza-Díaz de León L, Cordero-Molina S, Krams I, Contreras-Garduño J. Lie to me to lay with me: Females deceive males via terminal investment. PLoS One 2024; 19:e0301942. [PMID: 38976699 PMCID: PMC11230575 DOI: 10.1371/journal.pone.0301942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/25/2024] [Indexed: 07/10/2024] Open
Abstract
Historically, males have frequently been portrayed as the manipulative and deceptive gender, while females are often seen as adopting a coy and passive role. In this context, it is proposed that males use a terminal investment strategy, misleading females about their true poor condition, while females passively opt to mate with these deceptive males. However, we hypothesize that females in suboptimal condition may also engage in a terminal investment strategy by mimicking or enhancing their attractiveness to match that of females in better conditions. We studied this hypothesis in Tenebrio molitor, by subjecting females to three varying doses of lipopolysaccharides of Escherichia coli (LPS; 0.25, 0.5, or 1 mg ml-1), or three doses of the pro-oxidant Paraquat (PQ; 20, 40 or 80 mM), and subsequently assessing their survival and attractiveness to males. The LPS treatments and 20 mM of PQ had no significant effect on the survival or attractiveness of the females. However, females treated with 40 or 80 mM PQ survived fewer days compared to the control group. Those injected with 40 mM were more attractive than their control counterparts, while those treated with 80 mM were less attractive. Since the identical doses of LPS, which induce terminal investment in males, had no effect on females, we suggest sexual dimorphism in terminal investment. Furthermore, similar to males, if the stressor reaches a sufficiently high level, the signal becomes honest. These findings highlight how the quantity of stressors influences support for the terminal investment strategy in both males and females. Notably, this study challenges prevailing notions regarding gender roles in sexual selection, indicating that females, not just males, conceal their poor condition to attract mating partners.
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Affiliation(s)
- Laura Mendoza-Díaz de León
- Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Sagrario Cordero-Molina
- Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Indikris Krams
- Latvian Biomedical Research and Study Centre, Riga, Latvia
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
- Department of Zoology and Animal Ecology, Faculty of Biology, University of Latvia, Rīga, Latvia
| | - Jorge Contreras-Garduño
- Escuela Nacional de Estudios Superiores, Unidad Morelia, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
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2
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Liao A, Cavigliasso F, Savary L, Kawecki TJ. Effects of an entomopathogenic fungus on the reproductive potential of Drosophila males. Ecol Evol 2024; 14:e11242. [PMID: 38590549 PMCID: PMC10999951 DOI: 10.1002/ece3.11242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/10/2024] Open
Abstract
While mortality is often the primary focus of pathogen virulence, non-lethal consequences, particularly for male reproductive fitness, are less understood; however, they are essential for understanding how sexual selection contributes to promoting resistance. We investigated how the fungal pathogen Metarhizium brunneum affects mating ability, fertility, and seminal fluid protein (SFP) expression of male Drosophila melanogaster paired with highly receptive virgin females in non-competitive settings. Depending on sex and dose, there was a 3-6-day incubation period after infection, followed by an abrupt onset of mortality. Meanwhile, the immune response was strongly induced already 38 h after infection and continued to increase as infection progressed. Latency to mate somewhat increased during the incubation period compared to sham-treated males, but even on Day 5 post infection >90% of infected males mated within 2 h. During the incubation period, M. brunneum infection reduced male reproductive potential (the number of offspring sired without mate limitation) by 11%, with no clear increase over time. Approaching the end of the incubation period, infected males had lower ability to convert number of mating opportunities into number of offspring. After repeated mating, infected males had lower SFP expression than sham controls, more so in males that mated with few mates 24 h earlier. Overall, despite strong activation of the immune response, males' mating ability and fertility remained surprisingly little affected by the fungal infection, even shortly before the onset of mortality. This suggests that the selection for resistance acts mainly through mortality, and the scope for fertility selection to enhance resistance in non-competing settings is rather limited.
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Affiliation(s)
- Aijuan Liao
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Fanny Cavigliasso
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Loriane Savary
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
| | - Tadeusz J. Kawecki
- Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
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3
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Groot AT, Blankers T, Halfwerk W, Burdfield Steel E. The Evolutionary Importance of Intraspecific Variation in Sexual Communication Across Sensory Modalities. ANNUAL REVIEW OF ENTOMOLOGY 2024; 69:21-40. [PMID: 37562048 DOI: 10.1146/annurev-ento-030223-111608] [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: 08/12/2023]
Abstract
The evolution of sexual communication is critically important in the diversity of arthropods, which are declining at a fast pace worldwide. Their environments are rapidly changing, with increasing chemical, acoustic, and light pollution. To predict how arthropod species will respond to changing climates, habitats, and communities, we need to understand how sexual communication systems can evolve. In the past decades, intraspecific variation in sexual signals and responses across different modalities has been identified, but never in a comparative way. In this review, we identify and compare the level and extent of intraspecific variation in sexual signals and responses across three different modalities, chemical, acoustic, and visual, focusing mostly on insects. By comparing causes and possible consequences of intraspecific variation in sexual communication among these modalities, we identify shared and unique patterns, as well as knowledge needed to predict the evolution of sexual communication systems in arthropods in a changing world.
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Affiliation(s)
- Astrid T Groot
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Netherlands; , ,
| | - Thomas Blankers
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Netherlands; , ,
| | - Wouter Halfwerk
- Amsterdam Institute for Life and Environment (A-LIFE), VU Amsterdam, Netherlands;
| | - Emily Burdfield Steel
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Netherlands; , ,
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4
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Cantarero A, Dolnik OV, Griggio M, Hoi H. Mate choice is affected by parasite infestation rate of the choosing individual as well as of potential mating partners. Curr Zool 2023; 69:559-567. [PMID: 37637318 PMCID: PMC10449416 DOI: 10.1093/cz/zoac076] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 09/16/2022] [Indexed: 08/29/2023] Open
Abstract
Parasites are known to be a key driving force in mate choice and are important for the expression and evolution of ornaments and behavioral traits being used. However, there is little experimental evidence on how the parasite's burden of the choosing individual is integrated into the mate-choice process and how it affects decision-making, especially in relation to parasite infestation of potential mates. Thus, the aim of our study was to determine whether female house sparrows Passer domesticus adjust their mate preference according to their own as well as the parasite load of prospective partners. To do this, we experimentally manipulated female parasite load and determined their mate preferences prior to and after parasite treatment. We manipulated the chronic coccidian parasite burden of females either by initiating the acute infection phase via re-infecting them with coccidian or by temporally reducing the parasite load of coccidia. We then measured the effect of this manipulation on mate preference by presenting females with a choice of four stimuli: three males with similar ornaments, but unmanipulated, naturally varying chronic coccidiosis levels, and an unmanipulated control female. Additionally, we recorded some males' behavior in relation to their infection status pointing toward an increased or reduced interest in mating. We found that females preferred highly infested males prior to manipulation, regardless of their own infestation level. However, after manipulation, infested females avoided highly infested males probably in response to the deterioration of their health condition by parasites. Our study suggests that mate-choice decisions are more complex when they are mediated by parasites. The implications of parasites for evolutionary theories of sexual signaling and mate choice are discussed.
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Affiliation(s)
- Alejandro Cantarero
- Department of Physiology, Veterinary School, Complutense University of Madrid, Avenida Puerta de Hierro s/n, 28040 Madrid, Spain
| | - Olga V Dolnik
- Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology (KLIVV), University of Veterinary Medicine Vienna, Savoyenstraße 1a, A-1160 Vienna, Austria
| | - Matteo Griggio
- Dipartimento di Biologia, Università di Padova, Via U. Bassi 58/B, I-35131 Padova, Italy
| | - Herbert Hoi
- Department of Integrative Biology and Evolution, Konrad Lorenz Institute of Ethology (KLIVV), University of Veterinary Medicine Vienna, Savoyenstraße 1a, A-1160 Vienna, Austria
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5
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The Tapeworm Hymenolepis diminuta as an Important Model Organism in the Experimental Parasitology of the 21st Century. Pathogens 2022; 11:pathogens11121439. [PMID: 36558772 PMCID: PMC9784563 DOI: 10.3390/pathogens11121439] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/22/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
The tapeworm Hymenolepis diminuta is a common parasite of the small intestine in rodents but it can also infect humans. Due to its characteristics and ease of maintenance in the laboratory, H. diminuta is also an important model species in studies of cestodiasis, including the search for new drugs, treatments, diagnostics and biochemical processes, as well as its host-parasite interrelationships. A great deal of attention has been devoted to the immune response caused by H. diminuta in the host, and several studies indicate that infection with H. diminuta can reduce the severity of concomitant disease. Here, we present a critical review of the experimental research conducted with the use of H. diminuta as a model organism for over more than two decades (in the 21st century). The present review evaluates the tapeworm H. diminuta as a model organism for studying the molecular biology, biochemistry and immunology aspects of parasitology, as well as certain clinical applications. It also systematizes the latest research on this species. Its findings may contribute to a better understanding of the biology of tapeworms and their adaptation to parasitism, including complex correlations between H. diminuta and invertebrate and vertebrate hosts. It places particular emphasis on its value for the further development of modern experimental parasitology.
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Wittman TN, Carlson TA, Robinson CD, Bhave RS, Cox RM. Experimental removal of nematode parasites increases growth, sprint speed, and mating success in brown anole lizards. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:852-866. [PMID: 35871281 PMCID: PMC9796785 DOI: 10.1002/jez.2644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 01/07/2023]
Abstract
Parasites interact with nearly all free-living organisms and can impose substantial fitness costs by reducing host survival, mating success, and fecundity. Parasites may also indirectly affect host fitness by reducing growth and performance. However, experimentally characterizing these costs of parasitism is challenging in the wild because common antiparasite drug formulations require repeated dosing that is difficult to implement in free-living populations, and because the extended-release formulations that are commercially available for livestock and pets are not suitable for smaller animals. To address these challenges, we developed a method for the long-term removal of nematode parasites from brown anole lizards (Anolis sagrei) using an extended-release formulation of the antiparasite drug ivermectin. This treatment eliminated two common nematode parasites in captive adult males and dramatically reduced the prevalence and intensity of infection by these parasites in wild adult males and females. Experimental parasite removal significantly increased the sprint speed of captive adult males, the mating success of wild adult males, and the growth of wild juveniles of both sexes. Although parasite removal did not have any effect on survival in wild anoles, parasites may influence fitness directly through reduced mating success and indirectly through reduced growth and performance. Our method of long-term parasite manipulation via an extended-release formulation of ivermectin should be readily adaptable to many other small vertebrates, facilitating experimental tests of the extent to which parasites affect host phenotypes, fitness, and eco-evolutionary dynamics in the wild.
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Affiliation(s)
- Tyler N. Wittman
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Torun A. Carlson
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
| | | | - Rachana S. Bhave
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Robert M. Cox
- Department of BiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
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7
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Pham HT, Elgar MA, van Lieshout E, McNamara KB. Experimental immune challenges reduce the quality of male antennae and female pheromone output. Sci Rep 2022; 12:3578. [PMID: 35246550 PMCID: PMC8897396 DOI: 10.1038/s41598-022-07100-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 02/01/2022] [Indexed: 11/17/2022] Open
Abstract
Sexual signalling is a key feature of reproductive investment, yet the effects of immune system activation on investment into chemical signalling, and especially signal receiver traits such as antennae, are poorly understood. We explore how upregulation of juvenile immunity affects male antennal functional morphology and female pheromone attractiveness in the gumleaf skeletonizer moth, Uraba lugens. We injected final-instar larvae with a high or low dose of an immune elicitor or a control solution and measured male antennal morphological traits, gonad investment and female pheromone attractiveness. Immune activation affected male and female signalling investment: immune challenged males had a lower density of antennal sensilla, and the pheromone of immune-challenged females was less attractive to males than their unchallenged counterparts. Immune challenge affected female investment into ovary development but not in a linear, dose-dependent manner. While there was no effect of immune challenge on testes size, there was a trade-off between male pre- and post-copulatory investment: male antennal length was negatively correlated with testes size. Our study highlights the costs of elaborate antennae and pheromone production and demonstrates the capacity for honest signalling in species where the costs of pheromone production were presumed to be trivial.
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Affiliation(s)
- Hieu T Pham
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.,Department of Entomology, Faculty of Agronomy, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Mark A Elgar
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Emile van Lieshout
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Kathryn B McNamara
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
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8
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Rossi VS, de Mello IM, Barki A, Giaquinto PC. The attraction trick: males in early stages of disease become more chemically attractive to Nile tilapia (Oreochromis niloticus) females. JOURNAL OF FISH BIOLOGY 2021; 99:1632-1639. [PMID: 34350984 DOI: 10.1111/jfb.14870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/30/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
In aquatic systems, olfaction plays an important role in acquiring information about the social environment and influences important behaviours in various contexts, including predator avoidance, foraging, aggressive and reproductive behaviour and mate selection. As the presence of diseases might modify individual odour, fish may use the variability in conspecifics' odours as an indicator of the health status and infectious load of potential mates. Here, female Nile tilapia were tested for their ability to detect infected males and discriminate between bacterial infected and uninfected individuals by means of chemical cues. Females were allowed to choose between the odours of males infected by Aeromonas hydrophila bacteria and uninfected males. The findings show that female Nile tilapia initially showed a preference for infected males in terms of their first choice in a dichotomous choice test, but the total duration of time spent with the stimulus from infected males was not longer than that for the uninfected males. This may indicate that males at early stages of infection, i.e., without advanced clinical signs of infection, emit odours that allow them to enjoy the benefits of socialization when the infection is not yet detected by conspecifics. Thus, in the context of reproduction, males might attract female partners and have some chance of reproducing, before being avoided.
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Affiliation(s)
- Vanessa Stramantinoli Rossi
- Laboratory of Physiology and Animal Behaviour/Physiology Department, State University of São Paulo, São Paulo, Brazil
| | - Isabela Maria de Mello
- Laboratory of Physiology and Animal Behaviour/Physiology Department, State University of São Paulo, São Paulo, Brazil
| | - Assaf Barki
- Institute of Animal Science, The Volcani Center, Agricultural Research Organization, Rishon LeZion, Israel
| | - Percilia Cardoso Giaquinto
- Laboratory of Physiology and Animal Behaviour/Physiology Department, State University of São Paulo, São Paulo, Brazil
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9
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How healthy is your mate? Sex-specific consequences of parasite infections in the moth Helicoverpa armigera. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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10
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Makin DF, Kotler BP, Brown JS, Garrido M, Menezes JFS. The Enemy Within: How Does a Bacterium Inhibit the Foraging Aptitude and Risk Management Behavior of Allenby's Gerbils? Am Nat 2020; 196:717-729. [PMID: 33211558 DOI: 10.1086/711397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractMicrobes inhabiting multicellular organisms have complex, often subtle effects on their hosts. Gerbillus andersoni allenbyi are commonly infected with Mycoplasma haemomuris-like bacteria, which may cause mild nutrient (choline, arginine) deficiencies. However, are there more serious ecological consequences of infection, such as effects on foraging aptitudes and risk management? We tested two alternatives: the nutrient compensation hypothesis (does nutrient deficiency induce infected gerbils to make up for the shortfall by foraging more and taking greater risks?) and (2) the lethargy hypothesis (do sick gerbils forage less, and are they compromised in their ability to detect predators or risky microhabitats?). We compared the foraging and risk management behavior of infected and noninfected gerbils. We experimentally infected gerbils with the bacteria, which allowed us to compare between noninfected, acutely infected (peak infection loads), and chronically infected (low infection loads) individuals. Our findings supported the lethargy hypothesis over the nutrient compensation hypothesis. Infected individuals incurred dramatically elevated foraging costs, including less efficient foraging, diminished "quality" of time spent vigilant, and increased owl predation. Interestingly, gerbils that were chronically infected (lower bacteria load) experienced larger ecological costs than acutely infected individuals (i.e., peak infection loads). This suggests that the debilitating effects of infection occur gradually, with a progressive decline in the quality of time gerbils allocated to foraging and managing risk. These increased long-term costs of infection demonstrate how small direct physiological costs of infection can lead to large indirect ecological costs. The indirect ecological costs of this parasite appear to be much greater than the direct physiological costs.
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11
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Reyes-Ramírez A, Sandoval-García IA, Rocha-Ortega M, Córdoba-Aguilar A. Mutual mate choice and its benefits for both sexes. Sci Rep 2020; 10:19492. [PMID: 33173125 PMCID: PMC7656247 DOI: 10.1038/s41598-020-76615-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/30/2020] [Indexed: 11/09/2022] Open
Abstract
In mating interactions, it is common in nature for both sexes to choose simultaneously. However, this mutual mate choice and its consequences for progeny has received relatively little study; an approach where both male and female condition is manipulated is thus desirable. We compared both sexes' preferences in Tenebrio molitor beetles when individual condition varied (healthy vs infected with a fungus), and observed the direct benefits of those preferences. We predicted that: (a) females and males in good condition would prefer high quality mates; (b) preferences would be weaker when the choosing individual is in poor condition (and thus less selective given, for example, time and energetic constrains); and, (c) high quality mates would lay a larger number of total eggs and/or viable eggs than low quality mates. We found that both males and females in good condition were not more likely to choose mates that were also in good condition. However, poor-condition animals were more likely to prefer similar quality animals, while high-condition animals did not necessarily prefer mates of similar condition. Choosing sick males or females had a negative impact on egg number and viability. Our results suggest a non-adaptive mate choice in this species. Possibly, a deteriorated condition may drive individuals to invest more in attracting mates, because their chances of surviving the infection are very low. However, we do not discount the possibility that the fungus is manipulating individuals to increase its transmission during mating.
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Affiliation(s)
- Alicia Reyes-Ramírez
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, Mexico
| | - Iván Antonio Sandoval-García
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, Mexico
| | - Maya Rocha-Ortega
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, Mexico
| | - Alex Córdoba-Aguilar
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, Mexico.
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12
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Ruiz‐Guzmán G, Cordero‐Molina S, Krams I, Contreras‐Garduño J. Interactions between oxidative stress and attractiveness to mates and individual mate choice in the beetle
Tenebrio molitor. Ethology 2020. [DOI: 10.1111/eth.13108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Gloria Ruiz‐Guzmán
- Laboratorio de Ecología Evolutiva Escuela Nacional de Estudios Superiores Universidad Nacional Autónoma de México Ciudad de México México
| | - Sagrario Cordero‐Molina
- Laboratorio de Ecología Evolutiva Escuela Nacional de Estudios Superiores Universidad Nacional Autónoma de México Ciudad de México México
| | - Indrikis Krams
- Institute of Ecology and Earth Sciences University of Tartu Tartu Estonia
- Department of Zoology and Animal Ecology Faculty of Biology University of Latvia Rīga Latvia
- Latvian Biomedical Research and Study Centre Rīga Latvia
| | - Jorge Contreras‐Garduño
- Laboratorio de Ecología Evolutiva Escuela Nacional de Estudios Superiores Universidad Nacional Autónoma de México Ciudad de México México
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13
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Szentiványi T, Estók P, Pigeault R, Christe P, Glaizot O. Effects of fungal infection on the survival of parasitic bat flies. Parasit Vectors 2020; 13:23. [PMID: 31931866 PMCID: PMC6958713 DOI: 10.1186/s13071-020-3895-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 01/07/2020] [Indexed: 11/10/2022] Open
Abstract
Background Parasites are able to alter numerous aspects of their hosts’ life history, behaviour and distribution. One central question in parasitology is to determine the degree of impact that parasites have on their hosts. Laboulbeniales (Fungi: Ascomycota) are ectoparasitic fungi of arthropods. Even though these fungi are widely distributed, little is known about their ecology and their possible physiological effects on their hosts. We used a highly specific bat fly-fungi association to assess the effect of these fungal parasites on their dipteran hosts. Methods We collected bat flies (Diptera: Nycteribiidae) belonging to two species, Nycteribia schmidlii and Penicillidia conspicua from their bat host Miniopterus schreibersii (Chiroptera: Miniopteridae). We experimentally tested the effect of infection on the lifespan of bat flies. Results The prevalence of Laboulbeniales fungi was 17.9% in N. schmidlii and 64.8% in P. conspicua. Two fungi species were identified, Arthrorhynchus eucampsipodae and A. nycteribiae, both showing strict host specificity with N. schmidlii and P. conspicua, respectively. We found that fungal infection reduced by half the survival rate of P. conspicua regardless of sex, whereas N. schmidlii was not affected by the infection. Moreover, the intensity of infection showed negative correlation with the lifespan of P. conspicua. Conclusions To our knowledge, this is the first indication that fungal infection can alter bat fly survival and thus may play a significant role in the population dynamics of these bat ectoparasites.![]()
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Affiliation(s)
- Tamara Szentiványi
- Museum of Zoology, Palais de Rumine, Place de la Riponne 6, 1014, Lausanne, Switzerland. .,Department of Ecology and Evolution, University of Lausanne, Biophore, 1015, Lausanne, Switzerland.
| | - Péter Estók
- Department of Zoology, Eszterházy Károly University, Eszterházy tér 1, 3300, Eger, Hungary
| | - Romain Pigeault
- Department of Ecology and Evolution, University of Lausanne, Biophore, 1015, Lausanne, Switzerland
| | - Philippe Christe
- Department of Ecology and Evolution, University of Lausanne, Biophore, 1015, Lausanne, Switzerland
| | - Olivier Glaizot
- Museum of Zoology, Palais de Rumine, Place de la Riponne 6, 1014, Lausanne, Switzerland.,Department of Ecology and Evolution, University of Lausanne, Biophore, 1015, Lausanne, Switzerland
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14
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The costs of the immune memory within generations. Naturwissenschaften 2019; 106:59. [DOI: 10.1007/s00114-019-1657-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 11/05/2019] [Accepted: 11/07/2019] [Indexed: 10/25/2022]
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15
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Reyes-Ramírez A, Rocha-Ortega M, Córdoba-Aguilar A. Female preferences when female condition and male ornament expression vary. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Abstract
Variation in the condition of females can affect their mate preferences. This may explain variation in the expression of male ornaments. We tested these ideas in the mealworm beetle (Tenebrio molitor), a species in which females choose males based on their pheromones. We modified female condition using diets that differed in proteins and carbohydrates. We then allowed females to choose among males in which we had previously modified pheromone expression (either by varying diets as in females, or by fungal infection). Females were offered a choice between two males, both of which had been fed the same diet as the female, but which differed in whether they were infected or not. We repeated the same diet and infection treatments to determine whether poor (lower carbohydrate) diets decrease survival in both sexes. There was no effect of female diet on mate choice, but the infection state of the male did have an effect, with infected males being preferred. It is possible that infected males invest their resources in producing pheromones rather than attacking the pathogen. Both sexes, independent of infection, had higher survival when fed carbohydrate-rich diets. The results showed no effect of female condition on their preferences, at least not prior to copulation.
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Affiliation(s)
- Alicia Reyes-Ramírez
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Coyoacán, Distrito Federal, México
| | - Maya Rocha-Ortega
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Coyoacán, Distrito Federal, México
| | - Alex Córdoba-Aguilar
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Coyoacán, Distrito Federal, México
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Woestmann L, Stucki D, Saastamoinen M. Life history alterations upon oral and hemocoelic bacterial exposure in the butterfly Melitaea cinxia. Ecol Evol 2019; 9:10665-10680. [PMID: 31624574 PMCID: PMC6787844 DOI: 10.1002/ece3.5586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 11/11/2022] Open
Abstract
Life history strategies often shape biological interactions by specifying the parameters for possible encounters, such as the timing, frequency, or way of exposure to parasites. Consequentially, alterations in life-history strategies are closely intertwined with such interaction processes. Understanding the connection between life-history alterations and host-parasite interactions can therefore be important to unveil potential links between adaptation to environmental change and changes in interaction processes. Here, we studied how two different host-parasite interaction processes, oral and hemocoelic exposure to bacteria, affect various life histories of the Glanville fritillary butterfly Melitaea cinxia. We either fed or injected adult butterflies with the bacterium Micrococcus luteus and observed for differences in immune defenses, reproductive life histories, and longevity, compared to control exposures. Our results indicate differences in how female butterflies adapt to the two exposure types. Orally infected females showed a reduction in clutch size and an earlier onset of reproduction, whereas a reduction in egg weight was observed for hemocoelically exposed females. Both exposure types also led to shorter intervals between clutches and a reduced life span. These results indicate a relationship between host-parasite interactions and changes in life-history strategies. This relationship could cast restrictions on the ability to adapt to new environments and consequentially influence the population dynamics of a species in changing environmental conditions.
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Affiliation(s)
- Luisa Woestmann
- Organismal and Evolutionary Biology Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | - Dimitri Stucki
- Organismal and Evolutionary Biology Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | - Marjo Saastamoinen
- Organismal and Evolutionary Biology Research ProgrammeFaculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
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Spicer ME, Pruitt JN, Keiser CN. Spiders, microbes and sex: Bacterial exposure on copulatory organs alters mating behaviour in funnel‐web spiders. Ethology 2019. [DOI: 10.1111/eth.12921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
| | - Jonathan N. Pruitt
- Department of Biological Sciences University of Pittsburgh Pittsburgh PA USA
| | - Carl N. Keiser
- Department of Biological Sciences University of Pittsburgh Pittsburgh PA USA
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Buzatto BA, Kotiaho JS, Assis LAF, Simmons LW. A link between heritable parasite resistance and mate choice in dung beetles. Behav Ecol 2019. [DOI: 10.1093/beheco/arz089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AbstractParasites play a central role in the adaptiveness of sexual reproduction. Sexual selection theory suggests a role for parasite resistance in the context of mate choice, but the evidence is mixed. The parasite-mediated sexual selection (PMSS) hypothesis derives a number of predictions, among which that resistance to parasites is heritable, and that female choice favors parasite resistance genes in males. Here, we tested the PMSS hypothesis using the dung beetle Onthophagus taurus, a species that can be heavily parasitized by Macrocheles merdarius mites, which are known to affect adult survival. We investigated the heritability of resistance to M. merdarius, as well as whether female O. taurus impose a mating bias against males susceptible to mite infestation. Female choice for parasite resistance is difficult to disentangle from the possibility that females are simply choosing less parasitized males due to naturally selected benefits of avoiding contracting those parasites. This is especially likely for ectoparasites, such as mites. We tackled this problem by performing a mate choice trial first, and then measuring a male’s resistance to mite infestation. Resistance to mite infestation exhibited significant levels of additive genetic variance. Although we found no relationship between mating success and parasite resistance, males with greater resistance to infestation mated for longer. If females control copula duration, given that short copulations often result in mating failure, female choice could act on parasite resistance.
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Affiliation(s)
- Bruno A Buzatto
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, Crawley, WA, Australia
- Department of Biological Sciences (E8C 209), Macquarie University, Sydney, NSW, Australia
| | - Janne S Kotiaho
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
- School of Resource Wisdom, University of Jyväskylä, Jyväskylä, Finland
| | - Larissa A F Assis
- Departamento de Ecologia, Instituto de Biociências, Rua do Matão, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Leigh W Simmons
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, Crawley, WA, Australia
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Vigneron A, Jehan C, Rigaud T, Moret Y. Immune Defenses of a Beneficial Pest: The Mealworm Beetle, Tenebrio molitor. Front Physiol 2019; 10:138. [PMID: 30914960 PMCID: PMC6422893 DOI: 10.3389/fphys.2019.00138] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 02/07/2019] [Indexed: 12/04/2022] Open
Abstract
The mealworm beetle, Tenebrio molitor, is currently considered as a pest when infesting stored grains or grain products. However, mealworms are now being promoted as a beneficial insect because their high nutrient content makes them a viable food source and because they are capable of degrading polystyrene and plastic waste. These attributes make T. molitor attractive for mass rearing, which may promote disease transmission within the insect colonies. Disease resistance is of paramount importance for both the control and the culture of mealworms, and several biotic and abiotic environmental factors affect the success of their anti-parasitic defenses, both positively and negatively. After providing a detailed description of T. molitor's anti-parasitic defenses, we review the main biotic and abiotic environmental factors that alter their presentation, and we discuss their implications for the purpose of controlling the development and health of this insect.
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Affiliation(s)
- Aurélien Vigneron
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, United States
| | - Charly Jehan
- UMR CNRS 6282 BioGéoSciences, Équipe Écologie Évolutive, Université Bourgogne-Franche Comté, Dijon, France
| | - Thierry Rigaud
- UMR CNRS 6282 BioGéoSciences, Équipe Écologie Évolutive, Université Bourgogne-Franche Comté, Dijon, France
| | - Yannick Moret
- UMR CNRS 6282 BioGéoSciences, Équipe Écologie Évolutive, Université Bourgogne-Franche Comté, Dijon, France
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Reyes-Ramírez A, Enríquez-Vara JN, Rocha-Ortega M, Téllez-García A, Córdoba-Aguilar A. Female choice for sick males over healthy males: Consequences for offspring. Ethology 2019. [DOI: 10.1111/eth.12854] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Alicia Reyes-Ramírez
- Departamento de Ecología Evolutiva, Instituto de Ecología; Ciudad Universitaria, Universidad Nacional Autónoma de México; Distrito Federal México
| | - Jhony N. Enríquez-Vara
- CONACYT-Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco AC; Zapopan Mexico
| | - Maya Rocha-Ortega
- Departamento de Ecología Evolutiva, Instituto de Ecología; Ciudad Universitaria, Universidad Nacional Autónoma de México; Distrito Federal México
| | - Aldo Téllez-García
- Departamento de Ecología Evolutiva, Instituto de Ecología; Ciudad Universitaria, Universidad Nacional Autónoma de México; Distrito Federal México
| | - Alex Córdoba-Aguilar
- Departamento de Ecología Evolutiva, Instituto de Ecología; Ciudad Universitaria, Universidad Nacional Autónoma de México; Distrito Federal México
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Gallagher JD, Siva-Jothy MT, Evison SEF. Social cues trigger differential immune investment strategies in a non-social insect, Tenebrio molitor. Biol Lett 2018; 14:rsbl.2017.0709. [PMID: 29438053 DOI: 10.1098/rsbl.2017.0709] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/11/2018] [Indexed: 01/19/2023] Open
Abstract
Social immunization (SI) is a horizontal transfer of immunity that protects naive hosts against infection following exposure to infected nestmates. While mainly documented in eusocial insects, non-social species also share similar ecological features which favour the development of group-level immunity. Here, we investigate SI in Tenebrio molitor by pairing naive females with a pathogen-challenged conspecific for 72 h before measuring a series of immune and fitness traits. We found no evidence for SI, as beetles who cohabited with a live pathogen-challenged conspecific were not better protected against bacterial challenge. However, exposure to a heat-killed-bacteria-challenged conspecific appeared to increase pathogen tolerance, which manifested in differential fitness investment. Our results together suggest that T. molitor do respond to immune-related cues in the social environment, despite not showing a classic immunization response as predicted.
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Affiliation(s)
- Joe D Gallagher
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Michael T Siva-Jothy
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Sophie E F Evison
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
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Fortin M, Debenest C, Souty‐Grosset C, Richard F. Males prefer virgin females, even if parasitized, in the terrestrial isopod Armadillidium vulgare. Ecol Evol 2018; 8:3341-3353. [PMID: 29607029 PMCID: PMC5869267 DOI: 10.1002/ece3.3858] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 12/06/2017] [Accepted: 12/22/2017] [Indexed: 02/05/2023] Open
Abstract
In many species, males increase their reproductive success by choosing high-quality females. In natural populations, they interact with both virgin and mated females, which can store sperm in their spermatheca. Therefore, males elaborate strategies to avoid sperm competition. In the terrestrial isopod Armadillidium vulgare, females can store sperm and produce several clutches. Moreover, this species can be parasitized by Wolbachia, which feminizes genetic males, transforming them into functional females. Our study compared attractiveness and mate choice when a male is exposed to both virgin and experienced females (i.e., females who have produced offspring and rested for 6 months), with or without Wolbachia. Our results revealed that males are more attracted to virgin females than experienced females, even if these virgin females are parasitized. Moreover, the chemical analysis highlighted different odors in females according to their reproductive and infection (Wolbachia-free or vertically Wolbachia-infected) status. Males attempted copulation more frequently and for longer with virgin females, even if Wolbachia-infected, while experienced females refused further copulation. The evolutionary consequences of both male choice and female resistance on their fitness are discussed in this study.
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Affiliation(s)
- Margot Fortin
- Laboratoire Ecologie et Biologie des InteractionsEquipe “Ecologie, Evolution, Symbiose”Université de Poitiers, UMR CNRS 7267PoitiersFrance
| | - Catherine Debenest
- Laboratoire Ecologie et Biologie des InteractionsEquipe “Ecologie, Evolution, Symbiose”Université de Poitiers, UMR CNRS 7267PoitiersFrance
| | - Catherine Souty‐Grosset
- Laboratoire Ecologie et Biologie des InteractionsEquipe “Ecologie, Evolution, Symbiose”Université de Poitiers, UMR CNRS 7267PoitiersFrance
| | - Freddie‐Jeanne Richard
- Laboratoire Ecologie et Biologie des InteractionsEquipe “Ecologie, Evolution, Symbiose”Université de Poitiers, UMR CNRS 7267PoitiersFrance
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24
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Body size and lifespan are condition dependent in the mealworm beetle, Tenebrio molitor, but not sexually selected traits. Behav Ecol Sociobiol 2018. [DOI: 10.1007/s00265-018-2444-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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25
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Megía-Palma R, Paranjpe D, Reguera S, Martínez J, Cooper RD, Blaimont P, Merino S, Sinervo B. Multiple color patches and parasites in Sceloporus occidentalis: differential relationships by sex and infection. Curr Zool 2018; 64:703-711. [PMID: 30538729 PMCID: PMC6280098 DOI: 10.1093/cz/zoy007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 01/16/2018] [Indexed: 11/23/2022] Open
Abstract
Parasites generally have a negative influence on the color expression of their hosts. Sexual selection theory predicts resistant high-quality individuals should show intense coloration, whereas susceptible low-quality individuals would show poor coloration. However, intensely colored males of different species of Old and New World lizards were more often infected by hemoparasites. These results suggest that high-quality males, with intense coloration, would suffer higher susceptibility to hemoparasites. This hypothesis remains poorly understood and contradicts general theories on sexual selection. We surveyed a population of Sceloporus occidentalis for parasites and found infections by the parasite genera Lankesterella and Acroeimeria. In this population, both males and females express ventral blue and yellow color patches. Lankesterella was almost exclusively infecting males. The body size of the males significantly predicted the coloration of both blue and yellow patches. Larger males showed darker (lower lightness) blue ventral patches and more saturated yellow patches that were also orange-skewed. Moreover, these males were more often infected by Lankesterella than smaller males. The intestinal parasite Acroeimeria infected both males and females. The infection by intestinal parasites of the genus Acroeimeria was the best predictor for the chroma in the blue patch of the males and for hue in the yellow patch of the females. Those males infected by Acroeimeria expressed blue patches with significantly lower chroma than the uninfected males. However, the hue of the yellow patch was not significantly different between infected and uninfected females. These results suggest a different effect of Lankesterella and Acroeimeria on the lizards. On the one hand, the intense coloration of male lizards infected by Lankesterella suggested high-quality male lizards may tolerate it. On the other hand, the low chroma of the blue coloration of the infected males suggested that this coloration could honestly express the infection by Acroeimeria.
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Affiliation(s)
- Rodrigo Megía-Palma
- Department of Ecología Evolutiva, Museo Nacional de Ciencias Naturales-CSIC, José Gutiérrez Abascal 2., Madrid, Spain
| | - Dhanashree Paranjpe
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA, USA
| | - Senda Reguera
- Department of Zoología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Javier Martínez
- Area Parasitología, Department of Biomedicina y Biotecnología, Área de Parasitología, Facultad de Farmacia, Universidad de Alcalá de Henares, Alcalá de Henares, Madrid, Spain
| | - Robert D Cooper
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA, USA
| | - Pauline Blaimont
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA, USA
| | - Santiago Merino
- Department of Ecología Evolutiva, Museo Nacional de Ciencias Naturales-CSIC, José Gutiérrez Abascal 2., Madrid, Spain
| | - Barry Sinervo
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 1156 High St, Santa Cruz, CA, USA
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Abstract
Although reproductive strategies can be influenced by a variety of intrinsic and extrinsic factors, life history theory provides a rigorous framework for explaining variation in reproductive effort. The terminal investment hypothesis proposes that a decreased expectation of future reproduction (as might arise from a mortality threat) should precipitate increased investment in current reproduction. Terminal investment has been widely studied, and a variety of intrinsic and extrinsic cues that elicit such a response have been identified across an array of taxa. Although terminal investment is often treated as a static strategy, the level at which a cue of decreased future reproduction is sufficient to trigger increased current reproductive effort (i.e., the terminal investment threshold) may depend on context, including the internal state of the organism or its current external environment, independent of the cue that triggers a shift in reproductive investment. Here, we review empirical studies that address the terminal investment hypothesis, exploring both the intrinsic and extrinsic factors that mediate its expression. Based on these studies, we propose a novel framework within which to view the strategy of terminal investment, incorporating factors that influence an individual's residual reproductive value beyond a terminal investment trigger - the dynamic terminal investment threshold.
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Foo YZ, Simmons LW, Rhodes G. The relationship between health and mating success in humans. ROYAL SOCIETY OPEN SCIENCE 2017; 4:160603. [PMID: 28280558 PMCID: PMC5319324 DOI: 10.1098/rsos.160603] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 12/12/2016] [Indexed: 05/27/2023]
Abstract
Health has been claimed to play an important role in human sexual selection, especially in terms of mate choice. Our preferences for attractive individuals are said to represent evolved adaptations for finding high-quality, healthy mates. If this is true, then we expect health to predict mating success in humans. We tested this hypothesis using several important physiological indicators of health, including immune function, oxidative stress and semen quality, and self-reported measures of sexual behaviour that contribute to mating success. In contrast to our hypothesis, we did not find a relationship between the physiological measures of health and sexual behaviour. Our results provide little support for claims that health, at least the health measures we used, increases mating success in relatively healthy humans.
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Affiliation(s)
- Yong Zhi Foo
- ARC Centre of Excellence in Cognition and its Disorders, School of Psychology, University of Western Australia, 35 Stirling Highway, Crawley, 6009 Western Australia, Australia
- Centre for Evolutionary Biology and School of Animal Biology, University of Western Australia, 35 Stirling Highway, Crawley, 6009 Western Australia, Australia
| | - Leigh W. Simmons
- ARC Centre of Excellence in Cognition and its Disorders, School of Psychology, University of Western Australia, 35 Stirling Highway, Crawley, 6009 Western Australia, Australia
- Centre for Evolutionary Biology and School of Animal Biology, University of Western Australia, 35 Stirling Highway, Crawley, 6009 Western Australia, Australia
| | - Gillian Rhodes
- ARC Centre of Excellence in Cognition and its Disorders, School of Psychology, University of Western Australia, 35 Stirling Highway, Crawley, 6009 Western Australia, Australia
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Chemnitz J, Jentschke PC, Ayasse M, Steiger S. Beyond species recognition: somatic state affects long-distance sex pheromone communication. Proc Biol Sci 2016; 282:20150832. [PMID: 26180067 DOI: 10.1098/rspb.2015.0832] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Long-range sex pheromones have been subjected to substantial research with a particular focus on their biosynthesis, peripheral perception, central processing and the resulting orientation behaviour of perceivers. Fundamental to the research on sex attractants was the assumption that they primarily coordinate species recognition. However, especially when they are produced by the less limiting sex (usually males), the evolution of heightened condition dependence might be expected and long-range sex pheromones might, therefore, also inform about a signaller's quality. Here we provide, to our knowledge, the first comprehensive study of the role of a male's long-range pheromone in mate choice that combines chemical analyses, video observations and field experiments with a multifactorial manipulation of males' condition. We show that the emission of the long-distance sex pheromone of the burying beetle, Nicrophorus vespilloides is highly condition-dependent and reliably reflects nutritional state, age, body size and parasite load--key components of an individual's somatic state. Both, the quantity and ratio of the pheromone components were affected but the time invested in pheromone emission was largely unaffected by a male's condition. Moreover, the variation in pheromone emission caused by the variation in condition had a strong effect on the attractiveness of males in the field, with males in better nutritional condition, of older age, larger body size and bearing less parasites being more attractive. That a single pheromone is influenced by so many aspects of the somatic state and causes such variation in a male's attractiveness under field conditions was hitherto unknown and highlights the need to integrate indicator models of sexual selection into pheromone research.
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Affiliation(s)
- Johanna Chemnitz
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm 89081, Germany
| | - Petra C Jentschke
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm 89081, Germany
| | - Manfred Ayasse
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm 89081, Germany
| | - Sandra Steiger
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm 89081, Germany
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Barthel A, Staudacher H, Schmaltz A, Heckel DG, Groot AT. Sex-specific consequences of an induced immune response on reproduction in a moth. BMC Evol Biol 2015; 15:282. [PMID: 26672978 PMCID: PMC4681174 DOI: 10.1186/s12862-015-0562-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 12/08/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Immune response induction benefits insects in combatting infection by pathogens. However, organisms have a limited amount of resources available and face the dilemma of partitioning resources between immunity and other life-history traits. Since males and females differ in their life histories, sex-specific resource investment strategies to achieve an optimal immune response following an infection can be expected. We investigated immune response induction of females and males of Heliothis virescens in response to the entomopathogenic bacterium Serratia entomophila, and its effects on mating success and the female sexual signal. RESULTS We found that females had higher expression levels of immune-related genes after bacterial challenge than males. However, males maintained a higher baseline expression of immune-related genes than females. The increased investment in immunity of female moths was negatively correlated with mating success and the female sexual signal. Male mating success was unaffected by bacterial challenge. CONCLUSIONS Our results show that the sexes differed in their investment strategies: females invested in immune defense after a bacterial challenge, indicating facultative immune deployment, whereas males had higher baseline immunity than females, indicating immune maintenance. Interestingly, these differences in investment were reflected in the mate choice assays. As female moths are the sexual signallers, females need to invest resources in their attractiveness. However, female moths appeared to invest in immunity at the cost of reproductive effort.
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Affiliation(s)
- Andrea Barthel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany.
| | - Heike Staudacher
- University of Amsterdam, IBED, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
| | - Antje Schmaltz
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany.
| | - David G Heckel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany.
| | - Astrid T Groot
- Department of Entomology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745, Jena, Germany.
- University of Amsterdam, IBED, Science Park 904, 1098 XH, Amsterdam, The Netherlands.
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Lai YT, Kekäläinen J, Kortet R. Infestation with the parasitic nematode Philometra ovata does not impair behavioral sexual competitiveness or odor attractiveness of the male European minnow (Phoxinus phoxinus). Acta Ethol 2015. [DOI: 10.1007/s10211-015-0229-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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31
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Landis SH, Sundin J, Rosenqvist G, Poirier M, Jørgensen GØ, Roth O. Female pipefish can detect the immune status of their mates. Behav Ecol Sociobiol 2015. [DOI: 10.1007/s00265-015-2004-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Shostak AW, Van Buuren KG, Cook R. Response of Flour Beetles to Multiple Stressors of Parasitic (Hymenolepis diminuta), Environmental (Diatomaceous Earth), and Host (Reproduction) Origin. J Parasitol 2015; 101:405-17. [PMID: 25932498 DOI: 10.1645/15-733.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Organisms face a multitude of potential stressors, and the way these stressors interact can provide insights into underlying biological processes. This study examined the flour beetle Tribolium confusum and its survival, net fecundity, and surface-seeking behavior in response to combinations of stressors from 3 categories. Infection by the cestode Hymenolepis diminuta provided a stress of parasitic origin. Exposure to diatomaceous earth (DE) provided a stress of environmental origin. Use of virgin and mated beetles evaluated reproduction as a stress of host origin. Single and multiple exposure of beetles to parasite eggs achieved a maximum mean abundance of 21 parasites/beetle and a maximum intensity of 90 parasites in an individual beetle. DE reduced initial parasite establishment, but did not directly affect survival of parasites after their establishment in the host. A rehydration technique was used to recover parasites from dead beetles, enabling this to be the first study to correlate H. diminuta intensity at time of death directly to mortality of T. confusum. A dichotomous intensity-mortality relationship was observed in 8% DE, whereby lightly infected (<20 parasites) hosts were killed by DE in an intensity-independent manner, but more heavily infected hosts were killed in an intensity-dependent manner. Host mating status did not affect host survival, but there were interactions among mating status, parasitism, and DE on net fecundity and surface-seeking behavior. However, these effects were minor compared to the host mortality that occurred when parasite abundance and DE concentration were both high. The aggregated distribution of T. confusum in beetles, the difficulty of achieving high mean abundances, and an apparent need for the stressors to have strong effects individually if they are to have enhanced effects when in combination, suggests that exposure to multiple stressors would seriously impact only a small proportion of the host population.
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Affiliation(s)
- Allen W Shostak
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9
| | - Kala G Van Buuren
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9
| | - Ranon Cook
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9
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Resource availability as a proxy for terminal investment in a beetle. Oecologia 2015; 178:339-45. [PMID: 25582868 DOI: 10.1007/s00442-014-3210-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 12/15/2014] [Indexed: 10/24/2022]
Abstract
Terminal investment hypothesis is a longstanding theoretical idea that organisms should increase their reproductive effort as their prospects for survival and reproduction decline. However, numerous attempts to test the terminal investment in reproduction have yielded contradictory results. This study reports an experimental confirmation of the terminal investment hypothesis. It was predicted that immune-challenged yellow mealworm beetles (Tenebrio molitor) are more likely to follow terminal investment strategy when their food resources are limited. Our results suggest the key role of food resources while making decisions to follow a terminal investment strategy. We found that male individuals invested in their sexual attractiveness at the expense of immune response and survival when food was not available. In contrast, the beetles did not decrease their lifespan and did not invest in the attractiveness of their sex odours under conditions of food ad libitum. Our results show the importance of food availability and quality in understanding the evolution of reproductive strategies.
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Steiger S, Stökl J. The Role of Sexual Selection in the Evolution of Chemical Signals in Insects. INSECTS 2014; 5:423-38. [PMID: 26462692 PMCID: PMC4592599 DOI: 10.3390/insects5020423] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 05/16/2014] [Accepted: 05/20/2014] [Indexed: 11/16/2022]
Abstract
Chemical communication is the most ancient and widespread form of communication. Yet we are only beginning to grasp the complexity of chemical signals and the role they play in sexual selection. Focusing on insects, we review here the recent progress in the field of olfactory-based sexual selection. We will show that there is mounting empirical evidence that sexual selection affects the evolution of chemical traits, but form and strength of selection differ between species. Studies indicate that some chemical signals are expressed in relation to an individual's condition and depend, for example, on age, immunocompetence, fertility, body size or degree of inbreeding. Males or females might benefit by choosing based on those traits, gaining resources or "good genes". Other chemical traits appear to reliably reflect an individual's underlying genotype and are suitable to choose a mating partner that matches best the own genotype.
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Affiliation(s)
- Sandra Steiger
- Institute of Experimental Ecology, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
| | - Johannes Stökl
- Institute of Zoology, University of Regensburg, Universitätstraße 31, 93053 Regensburg, Germany.
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Krams I, Daukste J, Kivleniece I, Krama T, Rantala MJ. Previous encapsulation response enhances within individual protection against fungal parasite in the mealworm beetle Tenebrio molitor. INSECT SCIENCE 2013; 20:771-777. [PMID: 23956033 DOI: 10.1111/j.1744-7917.2012.01574.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/05/2012] [Indexed: 06/02/2023]
Abstract
Immune defenses of insects show either broad reactions or specificity and durability of induced protection against attacking parasites and pathogens. In this study, we tested whether encapsulation response against nylon monofilament increases between two attempts of activation of immune system in mealworm beetles Tenebrio molitor, and whether previous exposure to nylon monofilament may also increase protection against an entomopathogenic fungus. We found that survival of beetles subjected to immune activation by nylon implant and subsequent fungal exposure a week later was significantly higher than survival of beetles which had been subjected to fungal infection only. This result suggests that previous immune activation by the nylon implant may be considered as broad spectrum "immune priming" which helps to fight not only the same intruder but also other parasites.
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Affiliation(s)
- Indrikis Krams
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia; Institute of Systematic Biology, University of Daugavpils, Daugavpils
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Shostak AW. Hymenolepis diminuta infections in tenebrionid beetles as a model system for ecological interactions between helminth parasites and terrestrial intermediate hosts: a review and meta-analysis. J Parasitol 2013; 100:46-58. [PMID: 23952690 DOI: 10.1645/13-347.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The cestode Hymenolepis diminuta (Cyclophyllidea) uses a variety of insects as its intermediate host, where ingestion of eggs results in development in the hemocoel of a cysticercoid that is infective to a rat definitive host. Species in 2 genera, Tenebrio and Tribolium (Coleoptera: Tenebrionidae) have been used extensively as laboratory intermediate hosts. This review examines experimental studies on ecological aspects of the relationship between H. diminuta and tenebrionid beetles, including the acquisition and establishment of the parasite, host effects on the parasite, and parasite effects on the host. A meta-analysis of infection results from the literature revealed strong relationships across host species and strains between (1) prevalence and intensity of infection, (2) efficiency of cysticercoid production and exposure conditions, and (3) variance in abundance or intensity of infection relative to their respective means. The underlying mechanisms producing these patterns remain elusive. Comparative studies are infrequent, and the use of divergent methodologies hampers comparisons among studies. In spite of these problems, there is much to recommend this as a terrestrial host-parasite model system. It represents those relationships in which mostly minor, but occasionally major, responses to parasitic infection occur, and in which host genetics and environmental conditions can serve as modifying factors. Moreover, this is a tractable experimental system, and is backed by an extensive literature on host biology.
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Affiliation(s)
- Allen W Shostak
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
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Pölkki M, Krams I, Kangassalo K, Rantala MJ. Inbreeding affects sexual signalling in males but not females of Tenebrio molitor. Biol Lett 2012; 8:423-5. [PMID: 22237501 DOI: 10.1098/rsbl.2011.1135] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In many species of animals, individuals advertise their quality with sexual signals to obtain mates. Chemical signals such as volatile pheromones are species specific, and their primary purpose is to influence mate choice by carrying information about the phenotypic and genetic quality of the sender. The deleterious effects of consanguineous mating on individual quality are generally known, whereas the effect of inbreeding on sexual signalling is poorly understood. Here, we tested whether inbreeding reduces the attractiveness of sexual signalling in the mealworm beetle, Tenebrio molitor, by testing the preferences for odours of inbred and outbred (control) individuals of the opposite sex. Females were more attracted to the odours produced by outbred males than the odours produced by inbred males, suggesting that inbreeding reduces the attractiveness of male sexual signalling. However, we did not find any difference between the attractiveness of inbred and outbred female odours, which may indicate that the quality of females is either irrelevant for T. molitor males or quality is not revealed through female odours.
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Affiliation(s)
- Mari Pölkki
- Department of Biology, Section of Ecology, University of Turku, Turku, Finland.
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Nielsen ML, Holman L. Terminal investment in multiple sexual signals: immune-challenged males produce more attractive pheromones. Funct Ecol 2011. [DOI: 10.1111/j.1365-2435.2011.01914.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Abstract
A secondary sexual character may act as an honest signal of the quality of the individual if the trait bears a cost and if its expression is phenotypically condition dependent. The cost of increasing the trait should be tolerable for individuals in good condition but not for those in a poor condition. The trait thus provides an honest signal of quality that enables the receiver to choose higher quality mates. Evidence for sex pheromones, which play a major role in shaping sexual evolution, inflicting a signaling cost is scarce. Here, we demonstrate that the amount of the major component of the pheromone in glands of Lobesia botrana (Lepidoptera) females at signaling time was significantly greater in large than in small females, that male moths preferred larger females as mates when responding to volatile signals, and small virgin females, but not large ones, exposed to conspecific pheromone, produced, when mated, significantly fewer eggs than nonexposed females. The latter indicates a condition-dependent cost of signaling. These results are in accordance with the predictions of condition-dependent honest signals. We therefore suggest that female signaling for males using sex pheromones bears a cost and thus calling may serve as honest advertisement for female quality.
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Affiliation(s)
- Ally R Harari
- Department of Entomology, the Volcani Center, Bet Dagan 50250, Israel.
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Krams I, Daukšte J, Kivleniece I, Krama T, Rantala MJ, Ramey G, Šauša L. Female choice reveals terminal investment in male mealworm beetles, Tenebrio molitor, after a repeated activation of the immune system. JOURNAL OF INSECT SCIENCE (ONLINE) 2011; 11:56. [PMID: 21864151 PMCID: PMC3281432 DOI: 10.1673/031.011.5601] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2010] [Accepted: 01/16/2011] [Indexed: 05/31/2023]
Abstract
Increasing evidence suggests that secondary sexual traits reflect immunocompetence of males in many animal species. This study experimentally investigated whether a parasite-like immunological challenge via a nylon implant affects sexual attractiveness of males in Tenebrio molitor L. (Coleoptera: Tenebrionidae) Although a single immunological challenge significantly reduced sexual attractiveness and locomotor activity of males, it had no adverse effect on their survival. A second immune challenge of the same males increased their attractiveness. However, it was found that the repeated challenge significantly reduced locomotor activity of males and caused higher mortality. This result indicates terminal investment on sexual signaling, which is supposedly based on a trade-off between pheromone production and energy expenditures needed for such activities as recovery of immune system and locomotor activity. When the third implantation was carried out in the same group of males, melanization of nylon implants was found to be lower in more attractive than in less attractive males. This suggests that males that became sexually attractive after the second immune challenge did not invest in recovery of their immune system.
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Affiliation(s)
- I Krams
- Department of Biology, University of Turku, FIN-20024 Turku, Finland
- Institute of Systematic Biology, University of Daugavpils, LV-5401 Daugavpils, Latvia
| | - J Daukšte
- Institute of Systematic Biology, University of Daugavpils, LV-5401 Daugavpils, Latvia
| | - I Kivleniece
- Institute of Systematic Biology, University of Daugavpils, LV-5401 Daugavpils, Latvia
| | - T Krama
- Institute of Systematic Biology, University of Daugavpils, LV-5401 Daugavpils, Latvia
| | - MJ Rantala
- Department of Biology, University of Turku, FIN-20024 Turku, Finland
| | - G Ramey
- Institute of Systematic Biology, University of Daugavpils, LV-5401 Daugavpils, Latvia
| | - L Šauša
- Department of Life Sciences, Anglia Ruskin University, Cambridge CB 1PT, UK
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Sexual attractiveness of immune-challenged male mealworm beetles suggests terminal investment in reproduction. Anim Behav 2010. [DOI: 10.1016/j.anbehav.2010.09.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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43
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Reaney LT, Knell RJ. Immune activation but not male quality affects female current reproductive investment in a dung beetle. Behav Ecol 2010. [DOI: 10.1093/beheco/arq139] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Heuschele J, Candolin U. Reversed parasite-mediated selection in sticklebacks from eutrophied habitats. Behav Ecol Sociobiol 2010. [DOI: 10.1007/s00265-010-0937-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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45
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Quantity discrimination in Tenebrio molitor: evidence of numerosity discrimination in an invertebrate? Anim Cogn 2009; 12:463-70. [PMID: 19118405 DOI: 10.1007/s10071-008-0207-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Revised: 12/12/2008] [Accepted: 12/15/2008] [Indexed: 10/21/2022]
Abstract
Numerosity discrimination, the ability to distinguish between sets with more and less items, is recognised as the foundation for higher numerical abilities. Understanding numerosity discrimination from a comparative perspective is hence pivotal in tracing the evolution of numerical representation systems. However, numerosity discrimination has been well studied only in vertebrates, where two innate systems of number representation have been described: an 'analog magnitude system' used to discriminate among numerosities by representing them as cardinal magnitudes and a 'parallel individualisation system' that allows precise discrimination among small arrays of items (< or =4) by representing objects individually. We investigated the existence of quantity discrimination in an insect species (Tenebrio molitor) by using a spontaneous two-choice procedure in which males were exposed to substrates bearing odours from different numbers of females (< or =4) in increasing numerosity ratios (1:4, 1:3 and 1:2). We show that males can discriminate sources of odours reflecting 1 versus 4 and 1 versus 3 females, but not 2 versus 4 or 1 versus 2, indicating that T. molitor males exhibit a marked preference for sources reflecting more female donors only when numerosity ratios are below 1:2. We discuss the functional significance of this finding and whether our pattern of results could be best explained by summation of a non-numerical continuous variable or by the existence of a numerosity discrimination mechanism with an operational signature ratio of 1:2.
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Richard FJ, Aubert A, Grozinger CM. Modulation of social interactions by immune stimulation in honey bee, Apis mellifera, workers. BMC Biol 2008; 6:50. [PMID: 19014614 PMCID: PMC2596086 DOI: 10.1186/1741-7007-6-50] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Accepted: 11/17/2008] [Indexed: 11/14/2022] Open
Abstract
Background Immune response pathways have been relatively well-conserved across animal species, with similar systems in both mammals and invertebrates. Interestingly, honey bees have substantially reduced numbers of genes associated with immune function compared with solitary insect species. However, social species such as honey bees provide an excellent environment for pathogen or parasite transmission with controlled environmental conditions in the hive, high population densities, and frequent interactions. This suggests that honey bees may have developed complementary mechanisms, such as behavioral modifications, to deal with disease. Results Here, we demonstrate that activation of the immune system in honey bees (using bacterial lipopolysaccharides as a non-replicative pathogen) alters the social responses of healthy nestmates toward the treated individuals. Furthermore, treated individuals expressed significant differences in overall cuticular hydrocarbon profiles compared with controls. Finally, coating healthy individuals with extracts containing cuticular hydrocarbons of immunostimulated individuals significantly increased the agonistic responses of nestmates. Conclusion Since cuticular hydrocarbons play a critical role in nestmate recognition and other social interactions in a wide variety of insect species, modulation of such chemical profiles by the activation of the immune system could play a crucial role in the social regulation of pathogen dissemination within the colony.
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Affiliation(s)
- F-J Richard
- Department of Entomology, WM Keck Center for Behavioral Biology, Gardner Hall, North Carolina State University, Raleigh, NC 27695, USA.
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Fedina TY, Lewis SM. An integrative view of sexual selection in Tribolium flour beetles. Biol Rev Camb Philos Soc 2008; 83:151-71. [PMID: 18429767 DOI: 10.1111/j.1469-185x.2008.00037.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sexual selection is a major force driving the evolution of diverse reproductive traits. This evolutionary process is based on individual reproductive advantages that arise either through intrasexual competition or through intersexual choice and conflict. While classical studies of sexual selection focused mainly on differences in male mating success, more recent work has focused on the differences in paternity share that may arise through sperm competition or cryptic female choice whenever females mate with multiple males. Thus, an integrative view of sexual selection needs to encompass processes that occur not only before copulation (pre-mating), but also during copulation (peri-mating), as well as after copulation (post-mating), all of which can generate differences in reproductive success. By encompassing mechanisms of sexual selection across all of these sequential reproductive stages this review takes an integrative approach to sexual selection in Tribolium flour beetles (Coleoptera: Tenebrionidae), a particularly well-studied and economically important model organism. Tribolium flour beetles colonize patchily distributed grain stores, and juvenile and adult stages share the same food resources. Adults are highly promiscuous and female reproduction is distributed across an adult lifespan lasting approximately 1 year. While Tribolium males produce an aggregation pheromone that attracts both sexes, there appears to be little pre-mating discrimination among potential mates by either sex. However, recent work has revealed several peri-mating and post-mating mechanisms that determine how offspring paternity is apportioned among a female's mates. During mating, Tribolium females reject spermatophore transfer and limit sperm numbers transferred by males with low phenotypic quality. Although there is some conflicting evidence, male copulatory leg-rubbing appears to be associated with overcoming female resistance to insemination and does not influence a male's subsequent paternity share. Evidence suggests that Tribolium beetles have several possible post-mating mechanisms that they may use to bias paternity. Male sperm precedence has been extensively studied in Tribolium spp. and the related Tenebrio molitor, and several factors influencing male paternity share among a female's progeny have been identified. These include oviposition time, inter-mating interval, male strain/genotype, the mating regimen of a male's mother, male starvation, and tapeworm infection. Females exert muscular control over sperm storage, although there is no evidence to date that females use this to differentiate among mates. Females could also influence offspring paternity by re-mating with additional males, and T. castaneum females more readily accept spermatophores when they are re-mating with more attractive males. Additional work is needed to examine the possible roles played by both male and female accessory gland products in determining male paternity share. Sexual selection during pre-mating episodes may be reinforced or counteracted by peri- and post-copulatory selection, and antagonistic coevolution between the sexes may be played out across reproductive stages. In Tribolium, males' olfactory attractiveness is positively correlated with both insemination success and paternity share, suggesting consistent selection across different reproductive stages. Similar studies across sequential reproductive stages are needed in other taxa to provide a more integrative view of sexual selection.
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Larval amphibian growth and development under varying density: are parasitized individuals poor competitors? Oecologia 2007; 155:641-9. [PMID: 18157552 DOI: 10.1007/s00442-007-0937-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Accepted: 12/03/2007] [Indexed: 10/22/2022]
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49
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Vainikka A, Rantala MJ, Seppälä O, Suhonen J. Do male mealworm beetles, Tenebrio molitor, sustain the honesty of pheromone signals under immune challenge? Acta Ethol 2007. [DOI: 10.1007/s10211-007-0031-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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50
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Carazo P, Font E, Alfthan B. Chemosensory assessment of sperm competition levels and the evolution of internal spermatophore guarding. Proc Biol Sci 2007; 274:261-7. [PMID: 17148255 PMCID: PMC1685850 DOI: 10.1098/rspb.2006.3714] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Males of many species adjust their reproductive behaviour according to the perceived risk of sperm competition. Although this phenomenon is widespread in insects and other animals, the mechanisms that allow mates to assess sperm competition levels remain largely unexplored. In this study, we analysed the mating behaviour of pairs of Tenebrio molitor beetles under three odour treatments representing increasing levels of sperm competition risk (SCR) and sperm competition intensity (SCI). Copula duration and male and female post-copulatory behaviour varied significantly with odour treatment. Both copula duration and post-copulatory associations (PCAs) increased significantly in odour treatments reflecting high male density. To our knowledge, this is the first study to report that insects may assess the actual density of potential competitors at the time of mating, a cue to SCR and SCI, on the basis of chemical cues. In T. molitor, males inhibit sperm release from the spermatophore of a rival male when remating takes place at short intervals. We show that, when sperm competition levels are high, PCAs increase female remating interval just above that necessary to prevent spermatophore inhibition by rival males. This finding strongly suggests that strategic male behaviour plays a 'spermatophore guarding' role in this species. Although common in insects with external spermatophore transfer, spermatophore guarding is not expected in species with rapid ejaculate transfer and internal spermatophore delivery. Our results reveal that spermatophore guarding may evolve, even under these circumstances, as an evolutionary response to short-term spermatophore inhibition or displacement mechanisms.
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Affiliation(s)
- P Carazo
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universidad de Valencia, Apartado 22085, 46071 Valencia, Spain.
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