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Derek S Sikes - One of the best experts on this subject based on the ideXlab platform.
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parental care and competition with microbes in carrion beetles a study of ecological adaptation
Animal Behaviour, 2016Co-Authors: Stephen T Trumbo, Derek S Sikes, Paula K B PhilbrickAbstract:The investigation of the function of a complex adaptation can benefit from multiple approaches. We used comparative study and physical simulation to re-examine the hypothesis that parental adaptations enable carrion beetles (Silphidae) to better compete with carrion microbes. The comparative study used two closely related species, Nicrophorus orbicollis and Ptomascopus morio, which differ markedly in their level of care. Reproductive performance was measured using carcasses aged on field soil for 0, 3, 6 or 9 days. As expected, N. orbicollis converted more carrion biomass to offspring biomass than did P. morio (27.8% versus 16.6% on fresh carcasses) and both species produced smaller broods on aged carcasses. There was a negative interaction, however, between the level of care and carcass age on reproductive performance; the parental care advantage exhibited by N. orbicollis was less on older carcasses than on fresh carcasses, and was negligible on the oldest (6- and 9-day) carcasses. Ptomascopus morio also demonstrated superior ability to regulate the size of offspring when using carcasses of various ages. In a second experiment, we simulated antimicrobial activity of Nicrophorus anal exudates. A 6-day pretreatment with an antibacterial, an antifungal, or a combination treatment did not result in larger broods relative to those on untreated 6-day carcasses. The results call into question the hypothesis that preparation of the carcass by Nicrophorus evolved primarily as an adaptation for preventing microbial deterioration of carrion. We suggest that selection to compete with microbes may be relaxed in carrion beetles that provide elaborate parental care. A small vertebrate carcass is a potential model system for applying the comparative method to ecological function.
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molecular phylogeny of the burying beetles coleoptera silphidae nicrophorinae
Molecular Phylogenetics and Evolution, 2013Co-Authors: Derek S Sikes, Chandra VenablesAbstract:Burying beetles (Silphidae: Nicrophorus) are well-known for their monopolization of small vertebrate carcasses in subterranean crypts and complex biparental care behaviors. They have been the focus of intense behavioral, ecological, and conservation research since the 1980s yet no thorough phylogenetic estimate for the group exists. Herein, we infer relationships, test past hypotheses of relationships, and test biogeographic scenarios among 55 of the subfamily Nicrophorinae's currently valid and extant 72 species. Two mitochondrial genes, COI and COII, and two nuclear genes, the D2 region of 28S, and the protein coding gene CAD, provided 3,971 nucleotides for 58 nicrophorine and 5 outgroup specimens. Ten partitions, with each modeled by GTR+I+G, were used for a 100 M generation MrBayes analysis and maximum likelihood bootstrapping with Garli. The inferred Bayesian phylogeny was mostly well-resolved with only three weak branches of biogeographic relevance. The common ancestor of the subfamily and of the genus Nicrophorus was reconstructed as Old World with four separate transitions to the New World and four reverse colonizations of the Old World from the New. Divergence dating from analysis with BEAST indicate the genus Nicrophorus originated in the Cretaceous, 127-99 Ma. Most prior, pre-cladistic hypotheses of relationships were strongly rejected while most modern hypotheses were largely congruent with monophyletic groups in our estimated phylogeny. Our results reject a recent hypothesis that Nicrophorus morio Gebler, 1817 (NEW STATUS as valid species) is a subspecies of N. germanicus (L., 1758). Two subgenera of Nicrophorus are recognized: NecroxenusSemenov-Tian-Shanskij, 1933, and NicrophorusFabricius, 1775.
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almost but not quite a subspecies a case of genetic but not morphological diagnosability in Nicrophorus coleoptera silphidae
Biological Journal of The Linnean Society, 2011Co-Authors: Tonya Mousseau, Derek S SikesAbstract:Allopatric populations that show genetic differentiation but lack phenotypic diagnosability are difficult to classify. In 1946, Arnett described a new species of burying beetle (Silphidae: Nicrophorus) from Luzon Island, Philippines, Nicrophorus benguetensis. In 2002, Sikes et al., finding the species to be inconsistently diagnosable, synonymized N. benguetensis under Nicrophorus nepalensis Hope 1831. We rigorously and quantitatively test the validity of N. benguetensis using several different species delimitation criteria. We employed discrete and quantitative character-based methods to test similarity criteria using linear morphometrics in a discriminant analysis framework, and percentage sequence divergences based on sequences from four mitochondrial DNA (mtDNA) genes (COI, COII, ND4 and ND5) and two nuclear genes [28S (D2 region) and CAD]. We also employed tree-based methods to test phylogenetic criteria using mtDNA sequences and morphology with parsimony, Bayesian inference and maximum likelihood. The analysis of discrete phenotypic characters did not reliably diagnose N. benguetensis. The results of the discriminant analysis provided moderate support for the validity of N. benguetensis (71.4% of the specimens were properly classified). There is adequate genetic distance between N. benguetensis and its nearest neighbour for DNA barcoding to identify an unknown sequence, although this may be an artefact of the small sample size. Phylogenetic analyses of the morphological data, with and without the morphometric data, yielded unresolved trees. Molecular phylogenetic results found N. benguetensis to be monophyletic, but neither clearly rejected nor supported its validity. Two of our approaches using molecular data diagnosed N. benguetensis, but those that used phenotypic data did not exceed a 75% success rate. We conclude, therefore, that N. benguetensis, despite being a weakly distinct allopatric population, and deserving of additional study, should remain synonymized until further analysis suggests otherwise. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102, 311–333.
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molecular systematics and biogeography of Nicrophorus in part the investigator species group coleoptera silphidae using mixture model mcmc
Molecular Phylogenetics and Evolution, 2008Co-Authors: Derek S Sikes, Stephen T Trumbo, Steven M Vamosi, Marcia Ricketts, Chandra VenablesAbstract:Abstract Burying beetles (Silphidae: Nicrophorus) are well-known for their biparental care and monopolization of small vertebrate carcasses in subterranean crypts. They have been the focus of intense behavioral ecological research since the 1980s yet no thorough phylogenetic estimate for the group exists. The relationships among the species, and the validity of some species, are poorly understood. Here, we infer the relationships and examine species boundaries among 50 individuals representing 15 species, primarily of the investigator species group, using a mixture-model Bayesian analysis. Two mitochondrial genes, COI and COII, were used, providing 2129 aligned nucleotides (567 parsimony-informative). The Akaike Information Criterion and Bayes Factors were used to select the best fitting model, in addition to Reversible Jump MCMC, which accommodated model uncertainty. A 21 parameter, three-partition GTR + G was the final model chosen. Despite a presumed Old World origin for the genus itself, the basal lineages and immediate outgroups of the investigator species group are New World species. Bayesian methods reconstruct the common ancestor of the investigator species group as New World and imply one later transition to the Old World with two return transitions to the New World. Prior hypotheses concerning the questionable validity of four species names, Nicrophorus praedator, Nicrophorus confusus, Nicrophorus encaustus and Nicrophorus mexicanus were tested. No evidence was found for the validity of the Nicrophorus investigator synonym N. praedator. We found evidence rejecting the species status of N. confusus (NEW SYNONYM of Nicrophorus sepultor). Weak evidence was found for the species status of N. encaustus and N. mexicanus, which are tentatively retained as valid. Our results strongly reject a recently published hypothesis that Nicrophorus interruptus (NEW STATUS as valid species) is a subspecies of N. investigator.
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revision of Nicrophorus in part new species and inferred phylogeny of the nepalensis group based on evidence from morphology and mitochondrial dna coleoptera silphidae nicrophorinae
Invertebrate Systematics, 2006Co-Authors: Derek S Sikes, Stephen T Trumbo, Ronald B MadgeAbstract:Carrion beetles of the genus Nicrophorus Fabricius, 1775 (Silphidae) are well known for their biparental brood care and monopolisation of small vertebrate carcasses in subterranean crypts. Although the taxonomy of New World species has received modern attention, the fauna of Asia, primarily of the nepalensis-group of species, has not. Herein we revise this species-group and describe as new the following seven species: Nicrophorus charon Sikes & Madge (Sulawesi), Nicrophorus herscheli Sikes & Madge (Sumatra), Nicrophorus insignis Sikes & Madge (Flores Island), Nicrophorus melissae Sikes & Madge (Nepal, Bhutan), Nicrophorus reticulatus Sikes & Madge (Guadalcanal), Nicrophorus schawalleri Sikes & Madge (Gansu, Shaanxi, Sichuan Province) and Nicrophorus trumboi Sikes & Madge (Nepal, Bhutan). We obtained a preliminary phylogeny using morphology and mtDNA (COII). This was inferred using maximum likelihood and Bayesian methods with the Mkv and GTR+I+G models (parsimony was rejected by the Akaike information criterion for being excessively parameter-rich). The phylogenetic signal in the morphological dataset was not strong and results were confounded by a ‘long-branch’ species, N. reticulatus. The signal was stronger in the combined dataset and the COII-only dataset. The molecular phylogeny supported the new status of species N. trumboi and N. melissae. Support was found for a mainland origin of the group with subsequent radiations into the Malay Archipelago.
Josef K Muller - One of the best experts on this subject based on the ideXlab platform.
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a comparison of tarsal morphology and traction force in the two burying beetles Nicrophorus nepalensis and Nicrophorus vespilloides coleoptera silphidae
Beilstein Journal of Nanotechnology, 2019Co-Authors: Liesa Schnee, Josef K Muller, Benjamin Sampalla, Oliver BetzAbstract:Our aim was to compare friction and traction forces between two burying beetle species of the genus Nicrophorus exhibiting different attachment abilities during climbing. Specifically, the interaction of adhesive hairs and claws during attachment with respect to various surface properties was investigated by using a 2 × 3 experimental design. Traction force was measured for two different surface energies (hydrophilic vs hydrophobic) varying in roughness from smooth to micro-rough to rough. Nanotribometric tests on single legs were also performed. The external morphology of the attachment devices investigated by scanning electron microscopy suggested higher intra-specific (intersexual) than inter-specific differences. Whereas differences between the two species in traction force were high on smooth surfaces, no differences could be detected between males and females within each species. With claws intact, both species showed the highest forces on rough surfaces, although N. nepalensis with clipped claws performed best on a smooth surface. However, N. nepalensis beetles outperformed N. vespilloides, which showed no differences between smooth and rough surfaces with clipped claws. Both species demonstrated poor traction forces on micro-rough surfaces. Results concerning the impact of surface polarity were inconclusive, whereas roughness more strongly affected the attachment performance in both species. Nanotribometric analyses of the fore tarsi performed on micro-rough and rough surfaces revealed higher friction in the proximal (pull) direction compared with the distal (push) direction. In these experiments, we detected neither differences in friction performance between the two species, nor clear trends concerning the influence of surface polarity. We conclude that the investigated morphological traits are not critical for the observed interspecific difference in attachment ability on smooth surfaces. Furthermore, interspecific differences in performance are only clear on smooth surfaces and vanish on micro-rough and rough surfaces. Our results suggest that even subtle differences in the adhesion-mediating secretion in closely related species might result in qualitative performance shifts.
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author correction volatiles emitted by calling males of burying beetles and ptomascopus morio coleoptera silphidae nicrophorinae are biogenetically related
Journal of Chemical Ecology, 2017Co-Authors: Wolf Haberer, Annekatrin Eggert, Thomas Schmitt, Peter Schreier, Josef K MullerAbstract:The original version of this article unfortunately contained a mistake. The name of the main component released by Nicrophorus defodiens in Fig. 1a should read "Fuscumyl acetate", not "Fuscumol".
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Volatiles Emitted by Calling Males of Burying Beetles and Ptomascopus morio (Coleoptera: Silphidae: Nicrophorinae) Are Biogenetically Related
Journal of Chemical Ecology, 2017Co-Authors: Wolf Haberer, Annekatrin Eggert, Thomas Schmitt, Peter Schreier, Josef K MullerAbstract:In burying beetles, Nicrophorus spp. (Coleoptera: Silphidae: Nicrophorinae) mate finding is mediated by male produced volatile compounds. To date, pheromone components of only two species have been identified. In an attempt to better understand the evolution of male pheromone signaling in burying beetles, we investigated the male released volatiles of ten Nicrophorus species and one closely related nicrophorine species, Ptomascopus mori. Volatiles emitted by calling males were collected in the laboratory by means of solid phase micro extraction and analyzed using gas chromatography coupled with mass spectrometry. Identified volatiles included short chain esters of 4-methylcarboxylic acids, terpenoids, and some other aliphatic compounds. The long-range volatile signals of the burying beetle species included in this study are blends of two to seven components. We found that methyl or ethyl esters of 4-methylheptanoic acid and 4-methyloctanoic acid are produced by eight of the ten investigated Nicrophorus species. These esters may play a key role in chemical communication. Their widespread occurrence suggests that these compounds did not evolve recently, but appeared relatively early in the phylogeny of the genus. Although Ptomascopus is considered the sister genus of Nicrophorus, P. morio males do not produce any of the Nicrophorus compounds, but release 3-methylalkan-2-ones, which are absent in Nicrophorus . A better understanding of the evolution of burying beetle pheromones, however, will only be possible once more species have been studied.
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maternal nutritional condition and genetic differentiation affect brood size and offspring body size in Nicrophorus
Zoology, 2007Co-Authors: Sandra Steiger, Katja Richter, Josef K Muller, Annekatrin EggertAbstract:In most animal species, brood size and body size exhibit some variation within and between populations. This is also true for burying beetles (genus Nicrophorus), a group in which the body size of offspring depends critically on the number of offspring competing for food due to the discrete nature of resource used for larval nutrition (vertebrate carcasses). In one species, brood size and body size are correlated with population density, and appear to be phenotypically plastic. We investigated potential proximate causes of between-population variation in brood size and body size in two species, Nicrophorus vespilloides and Nicrophorus defodiens. Our first experiment supported the notion that brood size is phenotypically plastic, because it was affected by environmental variation in adult nutritional condition. We found that the pre-breeding nutritional status of female N. vespilloides affected the number of eggs they laid, the number of surviving larvae in their broods, and the body size of their offspring. We do not know whether this plasticity is adaptive because greater offspring body size confers an advantage in contests over breeding resources, or whether starved females are constrained to produce smaller clutches because they cannot fully compensate for their poor pre-breeding nutritional status by feeding from the carcass. Our second experiment documents that brood size, specifically the infanticidal brood-size adjustment behavior, has undergone genetic differentiation between two populations of N. defodiens. Even under identical breeding conditions with identical numbers of first-instar larvae, females descended from the two populations produced broods of different size with corresponding differences in offspring body size.
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alternative tactics and individual reproductive success in natural associations of the burying beetle Nicrophorus vespilloides
Behavioral Ecology, 2007Co-Authors: Josef K Muller, Wenbe Hwang, Annekatrin Eggert, Veronika BraunischAbstract:Alternative reproductive tactics can be maintained through different evolutionary avenues. They can be genetically or stochastically determined, in which case they must yield equal fitness, or their use can be conditional, in which case the fitness payoff of alternatives may differ. We attempted to assess the reproductive success of alternative reproductive tactics employed by wild male and female burying beetles in natural associations on carcasses placed in the field. A beetle’s reproductive tactic was defined by its potential involvement in care of larvae, and parentage was assessed using oligolocus DNA fingerprinting of offspring and potential parents. Both in males and in females, alternative tactics yielded significantly different reproductive benefits: subordinate females (brood parasites) and males (satellite males) had considerably lower reproductive success than dominant or uncontested individuals. Joint breeding was too infrequent for statistical inferences, generating intermediate offspring numbers. About 15% of offspring were sired by males not present on the carcass, suggesting that mating away from reproductive resources can produce reproductive benefits to males. Our results, in concert with the observation that beetles using one tactic can be manipulated into employing the alternative, support the notion that Nicrophorus vespilloides uses alternatives conditionally, opportunistically employing lower-benefit tactics when more profitable tactics are not available, or as additional ‘‘on-the-side’’ tactics to bolster reproductive success. Key words: alternative tactics, brood parasitism, burying beetles, communal breeding, DNA fingerprinting, Nicrophorus, parentage, satellite males. [Behav Ecol]
Stephen T Trumbo - One of the best experts on this subject based on the ideXlab platform.
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parental care and competition with microbes in carrion beetles a study of ecological adaptation
Animal Behaviour, 2016Co-Authors: Stephen T Trumbo, Derek S Sikes, Paula K B PhilbrickAbstract:The investigation of the function of a complex adaptation can benefit from multiple approaches. We used comparative study and physical simulation to re-examine the hypothesis that parental adaptations enable carrion beetles (Silphidae) to better compete with carrion microbes. The comparative study used two closely related species, Nicrophorus orbicollis and Ptomascopus morio, which differ markedly in their level of care. Reproductive performance was measured using carcasses aged on field soil for 0, 3, 6 or 9 days. As expected, N. orbicollis converted more carrion biomass to offspring biomass than did P. morio (27.8% versus 16.6% on fresh carcasses) and both species produced smaller broods on aged carcasses. There was a negative interaction, however, between the level of care and carcass age on reproductive performance; the parental care advantage exhibited by N. orbicollis was less on older carcasses than on fresh carcasses, and was negligible on the oldest (6- and 9-day) carcasses. Ptomascopus morio also demonstrated superior ability to regulate the size of offspring when using carcasses of various ages. In a second experiment, we simulated antimicrobial activity of Nicrophorus anal exudates. A 6-day pretreatment with an antibacterial, an antifungal, or a combination treatment did not result in larger broods relative to those on untreated 6-day carcasses. The results call into question the hypothesis that preparation of the carcass by Nicrophorus evolved primarily as an adaptation for preventing microbial deterioration of carrion. We suggest that selection to compete with microbes may be relaxed in carrion beetles that provide elaborate parental care. A small vertebrate carcass is a potential model system for applying the comparative method to ecological function.
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molecular systematics and biogeography of Nicrophorus in part the investigator species group coleoptera silphidae using mixture model mcmc
Molecular Phylogenetics and Evolution, 2008Co-Authors: Derek S Sikes, Stephen T Trumbo, Steven M Vamosi, Marcia Ricketts, Chandra VenablesAbstract:Abstract Burying beetles (Silphidae: Nicrophorus) are well-known for their biparental care and monopolization of small vertebrate carcasses in subterranean crypts. They have been the focus of intense behavioral ecological research since the 1980s yet no thorough phylogenetic estimate for the group exists. The relationships among the species, and the validity of some species, are poorly understood. Here, we infer the relationships and examine species boundaries among 50 individuals representing 15 species, primarily of the investigator species group, using a mixture-model Bayesian analysis. Two mitochondrial genes, COI and COII, were used, providing 2129 aligned nucleotides (567 parsimony-informative). The Akaike Information Criterion and Bayes Factors were used to select the best fitting model, in addition to Reversible Jump MCMC, which accommodated model uncertainty. A 21 parameter, three-partition GTR + G was the final model chosen. Despite a presumed Old World origin for the genus itself, the basal lineages and immediate outgroups of the investigator species group are New World species. Bayesian methods reconstruct the common ancestor of the investigator species group as New World and imply one later transition to the Old World with two return transitions to the New World. Prior hypotheses concerning the questionable validity of four species names, Nicrophorus praedator, Nicrophorus confusus, Nicrophorus encaustus and Nicrophorus mexicanus were tested. No evidence was found for the validity of the Nicrophorus investigator synonym N. praedator. We found evidence rejecting the species status of N. confusus (NEW SYNONYM of Nicrophorus sepultor). Weak evidence was found for the species status of N. encaustus and N. mexicanus, which are tentatively retained as valid. Our results strongly reject a recently published hypothesis that Nicrophorus interruptus (NEW STATUS as valid species) is a subspecies of N. investigator.
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can the challenge hypothesis be applied to insects
Hormones and Behavior, 2007Co-Authors: Stephen T TrumboAbstract:The challenge hypothesis, conceived for testosterone and vertebrates, has recently been applied to juvenile hormone (JH) and insects. Scott [Scott, M.P., 2006a. Resource defense and juvenile hormone: the “challenge hypothesis” extended to insects. Horm. Behav. 49, 276–281] found that JH in the burying beetle Nicrophorus orbicollis increased in response to a social challenge in the presence of a breeding resource, while there was no such JH response in the purported brood parasite Nicrophorus pustulatus. Two important implications of the challenge hypothesis that need to be tested are whether JH affects dominance and why there are interspecific differences in the JH response to a social challenge. The effect of JH on dominance in burying beetles was examined by topical application of JH III to one of two competing females at 24 h and again at 1 h prior to presentation of a breeding resource (mouse carcass). JH supplementation had no effect on dominance in intraspecific interactions in N. orbicollis, as measured by possession of the carcass on Day 1, 3 or 7. Similarly, JH did not alter carcass ownership during competition between N. orbicollis and N. pustulatus nor did it affect reproductive success. Irrespective of JH supplementation, N. pustulatus became increasingly dominant as the trials progressed, rarely occupying the carcass on Day 1, but excluding N. orbicollis in nearly half the trials by Day 7. These findings, and a brief review of the burying beetle literature, suggest that the challenge hypothesis, as applied to testosterone and vertebrates, does not yet have an analogous model for JH and insects.
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revision of Nicrophorus in part new species and inferred phylogeny of the nepalensis group based on evidence from morphology and mitochondrial dna coleoptera silphidae nicrophorinae
Invertebrate Systematics, 2006Co-Authors: Derek S Sikes, Stephen T Trumbo, Ronald B MadgeAbstract:Carrion beetles of the genus Nicrophorus Fabricius, 1775 (Silphidae) are well known for their biparental brood care and monopolisation of small vertebrate carcasses in subterranean crypts. Although the taxonomy of New World species has received modern attention, the fauna of Asia, primarily of the nepalensis-group of species, has not. Herein we revise this species-group and describe as new the following seven species: Nicrophorus charon Sikes & Madge (Sulawesi), Nicrophorus herscheli Sikes & Madge (Sumatra), Nicrophorus insignis Sikes & Madge (Flores Island), Nicrophorus melissae Sikes & Madge (Nepal, Bhutan), Nicrophorus reticulatus Sikes & Madge (Guadalcanal), Nicrophorus schawalleri Sikes & Madge (Gansu, Shaanxi, Sichuan Province) and Nicrophorus trumboi Sikes & Madge (Nepal, Bhutan). We obtained a preliminary phylogeny using morphology and mtDNA (COII). This was inferred using maximum likelihood and Bayesian methods with the Mkv and GTR+I+G models (parsimony was rejected by the Akaike information criterion for being excessively parameter-rich). The phylogenetic signal in the morphological dataset was not strong and results were confounded by a ‘long-branch’ species, N. reticulatus. The signal was stronger in the combined dataset and the COII-only dataset. The molecular phylogeny supported the new status of species N. trumboi and N. melissae. Support was found for a mainland origin of the group with subsequent radiations into the Malay Archipelago.
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the reproductive biology of ptomascopus morio a brood parasite of Nicrophorus
Journal of Zoology, 2006Co-Authors: Stephen T Trumbo, Masahiro Kon, Derek S SikesAbstract:Nicrophorine beetles (Nicrophorus and Ptomascopus spp.) use small carcasses as a food source for young, a breeding ecology distinct from other silphid beetles. While adaptations to the use of small carcasses are well known for Nicrophorus (emitting sex pheromone, burying, rounding and removing hair from carcasses, regulating brood size, regurgitating to young, and preventing predation), there is little information regarding its sister group, Ptomascopus. Like Nicrophorus, Ptomascopus morio males emit pheromone to attract females. In the absence of carrion competitors Ptomascopus morio parents were found to stay with a carcass and their brood for up to 10 days. We tested six hypotheses to examine whether young benefit from this long period of parent‐offspring contact. (1) There was no evidence that parents buried or otherwise pre-empted carcasses to reduce competitive pressure. (2) We found no evidence that parents influenced the decomposition of the carcass. This was supported by experimental manipulations in which brood production (number of larvae and total brood mass) was no greater on carcasses on which parents were present than on carcasses not ‘prepared’ by parents. In addition, the carcass was not rounded and little hair was removed by the adults. (3) The presence of parents benefited the brood by reducing the negative effects of competition with carrion fly larvae. This likely resulted from predatory feeding by adult beetles. (4) Females adjusted clutch size to the size of the carcass. Parents, however, did not make a second adjustment in brood size after young reached the larval stage (filial cannibalism), as occurs in Nicrophorus. (5) Although parents were observed to open feeding holes in the carcass, this was not necessary for normal larval growth and survival. Parents were not observed to feed young directly by regurgitation. (6) Lastly, parents did not reduce predation on their brood when a conspecific intruder was present. These findings suggest that after the female parent adjusts clutch size to the size of the resource, the only parental benefit is clearing the carcass of fly larvae. Other differences with Nicrophorus include an extended period of oviposition (5 days) and less pronounced changes in ovarian mass and juvenile hormone titers in response to discovery of a carcass. In a field experiment in Kyoto, Japan, 17 of 21 broods of N. concolor during August contained larvae of P. morio. Mixed Nicrophorus‐Ptomascopus broods were less common at other times of the year and when N. quadripunctatus occupied carcasses. In the laboratory, P. morio was able to parasitize 19 of 20 broods of N. concolor. The pattern of oviposition, the absence of explicit parental behaviours, and the interactions with N. concolor in the field suggest that Ptomascopus morio is a brood parasite of Nicrophorus.
Annekatrin Eggert - One of the best experts on this subject based on the ideXlab platform.
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author correction volatiles emitted by calling males of burying beetles and ptomascopus morio coleoptera silphidae nicrophorinae are biogenetically related
Journal of Chemical Ecology, 2017Co-Authors: Wolf Haberer, Annekatrin Eggert, Thomas Schmitt, Peter Schreier, Josef K MullerAbstract:The original version of this article unfortunately contained a mistake. The name of the main component released by Nicrophorus defodiens in Fig. 1a should read "Fuscumyl acetate", not "Fuscumol".
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Volatiles Emitted by Calling Males of Burying Beetles and Ptomascopus morio (Coleoptera: Silphidae: Nicrophorinae) Are Biogenetically Related
Journal of Chemical Ecology, 2017Co-Authors: Wolf Haberer, Annekatrin Eggert, Thomas Schmitt, Peter Schreier, Josef K MullerAbstract:In burying beetles, Nicrophorus spp. (Coleoptera: Silphidae: Nicrophorinae) mate finding is mediated by male produced volatile compounds. To date, pheromone components of only two species have been identified. In an attempt to better understand the evolution of male pheromone signaling in burying beetles, we investigated the male released volatiles of ten Nicrophorus species and one closely related nicrophorine species, Ptomascopus mori. Volatiles emitted by calling males were collected in the laboratory by means of solid phase micro extraction and analyzed using gas chromatography coupled with mass spectrometry. Identified volatiles included short chain esters of 4-methylcarboxylic acids, terpenoids, and some other aliphatic compounds. The long-range volatile signals of the burying beetle species included in this study are blends of two to seven components. We found that methyl or ethyl esters of 4-methylheptanoic acid and 4-methyloctanoic acid are produced by eight of the ten investigated Nicrophorus species. These esters may play a key role in chemical communication. Their widespread occurrence suggests that these compounds did not evolve recently, but appeared relatively early in the phylogeny of the genus. Although Ptomascopus is considered the sister genus of Nicrophorus, P. morio males do not produce any of the Nicrophorus compounds, but release 3-methylalkan-2-ones, which are absent in Nicrophorus . A better understanding of the evolution of burying beetle pheromones, however, will only be possible once more species have been studied.
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Begging_Feeding
2017Co-Authors: Alexandra Capodeanu-nägler, Annekatrin Eggert, Heiko Vogel, Scott Sakaluk, Sandra SteigerAbstract:Begging and feeding rate of the three burying beetle species Nicrophorus orbicollis, N. pustulatus, and N. vespilloide
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maternal nutritional condition and genetic differentiation affect brood size and offspring body size in Nicrophorus
Zoology, 2007Co-Authors: Sandra Steiger, Katja Richter, Josef K Muller, Annekatrin EggertAbstract:In most animal species, brood size and body size exhibit some variation within and between populations. This is also true for burying beetles (genus Nicrophorus), a group in which the body size of offspring depends critically on the number of offspring competing for food due to the discrete nature of resource used for larval nutrition (vertebrate carcasses). In one species, brood size and body size are correlated with population density, and appear to be phenotypically plastic. We investigated potential proximate causes of between-population variation in brood size and body size in two species, Nicrophorus vespilloides and Nicrophorus defodiens. Our first experiment supported the notion that brood size is phenotypically plastic, because it was affected by environmental variation in adult nutritional condition. We found that the pre-breeding nutritional status of female N. vespilloides affected the number of eggs they laid, the number of surviving larvae in their broods, and the body size of their offspring. We do not know whether this plasticity is adaptive because greater offspring body size confers an advantage in contests over breeding resources, or whether starved females are constrained to produce smaller clutches because they cannot fully compensate for their poor pre-breeding nutritional status by feeding from the carcass. Our second experiment documents that brood size, specifically the infanticidal brood-size adjustment behavior, has undergone genetic differentiation between two populations of N. defodiens. Even under identical breeding conditions with identical numbers of first-instar larvae, females descended from the two populations produced broods of different size with corresponding differences in offspring body size.
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alternative tactics and individual reproductive success in natural associations of the burying beetle Nicrophorus vespilloides
Behavioral Ecology, 2007Co-Authors: Josef K Muller, Wenbe Hwang, Annekatrin Eggert, Veronika BraunischAbstract:Alternative reproductive tactics can be maintained through different evolutionary avenues. They can be genetically or stochastically determined, in which case they must yield equal fitness, or their use can be conditional, in which case the fitness payoff of alternatives may differ. We attempted to assess the reproductive success of alternative reproductive tactics employed by wild male and female burying beetles in natural associations on carcasses placed in the field. A beetle’s reproductive tactic was defined by its potential involvement in care of larvae, and parentage was assessed using oligolocus DNA fingerprinting of offspring and potential parents. Both in males and in females, alternative tactics yielded significantly different reproductive benefits: subordinate females (brood parasites) and males (satellite males) had considerably lower reproductive success than dominant or uncontested individuals. Joint breeding was too infrequent for statistical inferences, generating intermediate offspring numbers. About 15% of offspring were sired by males not present on the carcass, suggesting that mating away from reproductive resources can produce reproductive benefits to males. Our results, in concert with the observation that beetles using one tactic can be manipulated into employing the alternative, support the notion that Nicrophorus vespilloides uses alternatives conditionally, opportunistically employing lower-benefit tactics when more profitable tactics are not available, or as additional ‘‘on-the-side’’ tactics to bolster reproductive success. Key words: alternative tactics, brood parasitism, burying beetles, communal breeding, DNA fingerprinting, Nicrophorus, parentage, satellite males. [Behav Ecol]
Andreas Vilcinskas - One of the best experts on this subject based on the ideXlab platform.
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Nicrophorus_carcassmicrobiome_analysis
2017Co-Authors: Shantanu P. Shukla, Heiko Vogel, Andreas Vilcinskas, David G. Heckel, Martin KaltenpothAbstract:This contains files used in the analysis of the Nicrophorus vespilloides microbiome.It contains denoised, quality filtered reads for bacterial (Nvesp_16S_seqs.fna) and fungal (Nvesp_ITS_seqs.fna) datasets, metadata mapping files (16S_metadata.txt and ITS_metadata.txt), representative sequence sets for all OTUs (16S_rep_set.fna and ITS_repset.fasta) and the final OTU tables (16S_otutable.csv and ITS_otutable.csv)
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egg survival is reduced by grave soil microbes in the carrion beetle Nicrophorus vespilloides
BMC Evolutionary Biology, 2014Co-Authors: Chris Jacobs, Heiko Vogel, Andreas Vilcinskas, Yin Wang, Maurijn Van Der Zee, Daniel E RozenAbstract:Nicrophorus vespilloides eggs are deposited into the soil in close proximity to the decomposing vertebrate carcasses that these insects use as an obligate resource to rear their offspring. Eggs in this environment potentially face significant risks from the bacteria that proliferate in the grave-soil environment following nutrient influx from the decomposing carcass. Our aims in this paper are twofold: first, to examine the fitness effects of grave-soil bacteria to eggs, and second, to quantify egg immunocompetence as a defence against these bacteria. Our results provide strong evidence that grave-soil microbes significantly reduce the survival of Nicrophorus eggs. Females provided with microbe rich carcasses to rear broods laid fewer eggs that were less likely to hatch than females given uncontaminated carcasses. Furthermore, we show that egg hatch success is significantly reduced by bacterial exposure. Using a split-brood design, which controlled for intrinsic differences in eggs produced by different females, we found that eggs washed free of surface-associated bacteria show increased survival compared to unwashed eggs. By contrast, eggs exposed to the entomopathogen Serratia marcescens show decreased survival compared to unexposed eggs. We next tested the immune competence of eggs under challenge from bacterial infection, and found that eggs lacked endogenous production of antimicrobial peptides, despite well-developed responses in larvae. Finally, we found that despite lacking immunity, N. vespilloides eggs produce an extraembryonic serosa, indicating that the serosa has lost its immune inducing capacity in this species. The dependency on ephemeral resources might strongly select for fast developing animals. Our results suggest that Nicrophorus carrion beetles, and other species developing on ephemeral resources, face a fundamental trade-off between egg immunity and development time.
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identification of immunity related genes in the burying beetle Nicrophorus vespilloides by suppression subtractive hybridization
Insect Molecular Biology, 2011Co-Authors: Heiko Vogel, C Badapanda, Andreas VilcinskasAbstract:Burying beetles reproduce on small vertebrate cadavers which they bury in the soil after localization through volatiles emitted from the carcass. They then chemically preserve the carcass and prepare it as a diet for the adults and their offspring. It is predicted that exposure to high loads of soil and/or carrion-associated microbes necessitates an effective immune system. In the present paper, we report experimental screening for immunity-related genes in the burying beetle Nicrophorus vespilloides using the suppression subtractive hybridization approach. A total of 1179 putative gene objects were identified in the Nicrophorus cDNA library, which was enriched for transcripts differentially expressed upon challenge with heat-inactivated bacteria. In addition to genes known to be involved in immunity-related recognition and signalling, we found transcripts encoding for antimicrobial peptides and for an array of enzymes that can be linked to immunity or to stress-induced pathways. We also determined proteins that may contribute to detoxification of toxins produced by microbial competitors. In addition, factors involved in mRNA stability determination and central components of the RNA interference machinery were identified, implying transcriptional reprogramming and potential stress-induced retrotransposon elimination. The identified candidate immune effector and stress-related genes may provide important information about the unusual ecology and evolution of the burying beetles.