The nuptial flight of ants usually occurs during certain periods of the year. Alate females and males fly out of their nests to mate simultaneously. In the genus Camponotus, sex-specific chemicals are deposited in the male head; however, their roles in nuptial flight have not yet been clarified. This study aimed to elucidate the functions of male-specific chemicals in the Japanese carpenter ant Camponotus japonicus. First, we identified three chemicals characteristic to the male - methyl salicylate (MS), methyl 6-methylsalicylate (MMS), and methyl anthranilate (MA) - all of which triggered electroantennogram (EAG) responses in both alate males and females. As the relative content of MS was insufficient for GC comparison, we investigated the quantitative changes of MMS and MA in the male head capsules before and after flight under laboratory conditions. The amounts of both compounds were significantly reduced after flight, which suggested that males secrete them during flight. Thereafter, a field trap experiment was conducted in three fields of the Kyoto Prefecture, Japan, during the nuptial flight season in 2021 using MMS and MA as baits. The number of captured alate males was significantly higher than that of the females, suggesting that these compounds primarily attracted males rather than females. Considering the field conditions, if the local concentration of these chemicals is increased by male aggregation, females may be attracted as they also showed EAG responses. Our findings represent a first step toward understanding chemically mediated male lek formation during the process of male aggregation syndrome in this species.
蚂蚁的婚飞通常发生在一年中的某些时期。雌蚁和雄蚁同时飞出巢穴进行交配。在 Camponotus 属中,雄性头部沉积有性别特异性化学物质;然而,这些化学物质在交配飞行中的作用尚未明确。本研究旨在阐明日本木匠蚁(Camponotus japonicus)雄性特异性化学物质的功能。首先,我们确定了三种雄性特有的化学物质--水杨酸甲酯(MS)、6-甲基水杨酸甲酯(MMS)和蒽酸甲酯(MA)--它们都能触发雌雄蚁的电触角图(EAG)反应。由于MS的相对含量不足以进行气相色谱比较,我们在实验室条件下研究了雄性头囊中MMS和MA在飞行前后的定量变化。飞行后这两种化合物的含量明显减少,这表明雄性在飞行过程中会分泌这两种化合物。此后,在 2021 年的婚飞季节,以 MMS 和 MA 为诱饵,在日本京都府的三块田地进行了田间诱捕实验。结果表明,捕获的雌雄蚁数量明显高于雌蚁,这表明这些化合物主要吸引雄蚁而非雌蚁。考虑到野外条件,如果雄性聚集增加了这些化学物质的局部浓度,雌性可能也会被吸引,因为它们也表现出 EAG 反应。我们的研究结果为了解该物种雄性聚集综合征过程中化学介导的雄性蚁穴形成迈出了第一步。
{"title":"Male-Specific Substances Possibly Contributing to Nuptial Flight of the Japanese Carpenter Ant Camponotus japonicus (Hymenoptera: Formicidae).","authors":"Shunya Habe, Shigeru Matsuyama, Natsumi Kanzaki, Keiko Hamaguchi, Mamiko Ozaki, Toshiharu Akino","doi":"10.1007/s10886-024-01548-0","DOIUrl":"https://doi.org/10.1007/s10886-024-01548-0","url":null,"abstract":"<p><p>The nuptial flight of ants usually occurs during certain periods of the year. Alate females and males fly out of their nests to mate simultaneously. In the genus Camponotus, sex-specific chemicals are deposited in the male head; however, their roles in nuptial flight have not yet been clarified. This study aimed to elucidate the functions of male-specific chemicals in the Japanese carpenter ant Camponotus japonicus. First, we identified three chemicals characteristic to the male - methyl salicylate (MS), methyl 6-methylsalicylate (MMS), and methyl anthranilate (MA) - all of which triggered electroantennogram (EAG) responses in both alate males and females. As the relative content of MS was insufficient for GC comparison, we investigated the quantitative changes of MMS and MA in the male head capsules before and after flight under laboratory conditions. The amounts of both compounds were significantly reduced after flight, which suggested that males secrete them during flight. Thereafter, a field trap experiment was conducted in three fields of the Kyoto Prefecture, Japan, during the nuptial flight season in 2021 using MMS and MA as baits. The number of captured alate males was significantly higher than that of the females, suggesting that these compounds primarily attracted males rather than females. Considering the field conditions, if the local concentration of these chemicals is increased by male aggregation, females may be attracted as they also showed EAG responses. Our findings represent a first step toward understanding chemically mediated male lek formation during the process of male aggregation syndrome in this species.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142288132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-21DOI: 10.1007/s10886-024-01543-5
Nijat Narimanov, Jonna M Heuschele, Martin H Entling, Florian Menzel, Laia Mestre
Semiochemicals left by predators in their foraging area can be utilised by prey to avoid predation. The range of predators' chemical cues with contrasting degradation rates might provide information of different quality, potentially allowing prey to differentiate between the immediate and the longer-term presence of predators in a location. So far, knowledge about the roles of volatile versus stable chemical cues in informing predation risk is limited. We here seek to disentangle the role of ephemeral trail pheromones compared to persistent cuticular hydrocarbons of ants (predators) on the antipredator behaviour of juvenile spiders (prey), with the expectation that volatile semiochemicals induce avoidance behaviour in spiders at a higher rate compared to stable cues. We allowed the spiders to choose between sites with and without ant cues separately for volatile trail pheromones and stable hydrocarbons. Unexpectedly, spiders avoided the presence of persistent cuticular hydrocarbons more clearly than the highly volatile trail pheromone. This underscores the widespread impact of these stable cues on the avoidance behaviour of potential intraguild prey. The response to trail pheromones was unclear, possibly because spiders always encounter these cues simultaneously with visual and vibratory cues from ants; hence, trail pheromones may not contain any additional information, hindering the evolution of the ability to detect them.
{"title":"Differential Effects of Ephemeral and Stable Predator Chemical Cues on Spider Antipredator Behaviour.","authors":"Nijat Narimanov, Jonna M Heuschele, Martin H Entling, Florian Menzel, Laia Mestre","doi":"10.1007/s10886-024-01543-5","DOIUrl":"https://doi.org/10.1007/s10886-024-01543-5","url":null,"abstract":"<p><p>Semiochemicals left by predators in their foraging area can be utilised by prey to avoid predation. The range of predators' chemical cues with contrasting degradation rates might provide information of different quality, potentially allowing prey to differentiate between the immediate and the longer-term presence of predators in a location. So far, knowledge about the roles of volatile versus stable chemical cues in informing predation risk is limited. We here seek to disentangle the role of ephemeral trail pheromones compared to persistent cuticular hydrocarbons of ants (predators) on the antipredator behaviour of juvenile spiders (prey), with the expectation that volatile semiochemicals induce avoidance behaviour in spiders at a higher rate compared to stable cues. We allowed the spiders to choose between sites with and without ant cues separately for volatile trail pheromones and stable hydrocarbons. Unexpectedly, spiders avoided the presence of persistent cuticular hydrocarbons more clearly than the highly volatile trail pheromone. This underscores the widespread impact of these stable cues on the avoidance behaviour of potential intraguild prey. The response to trail pheromones was unclear, possibly because spiders always encounter these cues simultaneously with visual and vibratory cues from ants; hence, trail pheromones may not contain any additional information, hindering the evolution of the ability to detect them.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142288131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.1007/s10886-024-01545-3
Melissa Díaz-Morales, Mohammed A. Khallaf, Regina Stieber, Ibrahim Alali, Bill S. Hansson, Markus Knaden
Sex pheromones play a crucial role in species recognition and reproductive isolation. Despite being largely species-specific in drosophilids, the mechanisms underlying pheromone detection, production, and their influence on mating behavior remain poorly understood. Here, we compare the chemical profiles of Drosophila bipectinata and D. melanogaster, the mating behaviors in both species, as well as the tuning properties of Or67d receptors, which are expressed by neurons in antennal trichoid sensilla at1. Through single sensillum recordings, we demonstrate that the D. bipectinata Or67d-ortholog exhibits similar sensitivity to cis-vaccenyl acetate (cVA) as compared to D. melanogaster but in addition also responds uniquely to (Z)-11-eicosen-1-yl-acetate (Z11-20:Ac), a compound exclusively produced by D. bipectinata males. Through courtship behavior assays we found that, surprisingly, perfuming the flies with Z11-20:Ac did not reveal any aphrodisiacal or anti-aphrodisiacal effects in mating assays. The behavioral relevance of at1 neuron channels in D. bipectinata compared to D. melanogaster seems to be restricted to its formerly shown function as an aggregation pheromone. Moreover, the non-specific compound cVA affected copulation negatively in D. bipectinata and could potentially act as a premating isolation barrier. As both ligands of Or67d seem to govern different behaviors in D. bipectinata, additional neurons detecting at least one of those compounds might be involved. These results underscore the complexity of chemical signaling in species recognition and raise intriguing questions about the evolutionary implications of pheromone detection pathways in Drosophila species.
{"title":"The Ortholog Receptor Or67d in Drosophila Bipectinata is able to Detect Two Different Pheromones","authors":"Melissa Díaz-Morales, Mohammed A. Khallaf, Regina Stieber, Ibrahim Alali, Bill S. Hansson, Markus Knaden","doi":"10.1007/s10886-024-01545-3","DOIUrl":"https://doi.org/10.1007/s10886-024-01545-3","url":null,"abstract":"<p>Sex pheromones play a crucial role in species recognition and reproductive isolation. Despite being largely species-specific in drosophilids, the mechanisms underlying pheromone detection, production, and their influence on mating behavior remain poorly understood. Here, we compare the chemical profiles of <i>Drosophila bipectinata</i> and <i>D. melanogaster</i>, the mating behaviors in both species, as well as the tuning properties of Or67d receptors, which are expressed by neurons in antennal trichoid sensilla at1. Through single sensillum recordings, we demonstrate that the <i>D. bipectinata</i> Or67d-ortholog exhibits similar sensitivity to <i>cis</i>-vaccenyl acetate (<i>c</i>VA) as compared to <i>D.</i> melanogaster but in addition also responds uniquely to (Z)-11-eicosen-1-yl-acetate (Z11-20:Ac), a compound exclusively produced by <i>D. bipectinata</i> males. Through courtship behavior assays we found that, surprisingly, perfuming the flies with Z11-20:Ac did not reveal any aphrodisiacal or anti-aphrodisiacal effects in mating assays. The behavioral relevance of at1 neuron channels in <i>D. bipectinata</i> compared to <i>D. melanogaster</i> seems to be restricted to its formerly shown function as an aggregation pheromone. Moreover, the non-specific compound cVA affected copulation negatively in <i>D. bipectinata</i> and could potentially act as a premating isolation barrier. As both ligands of Or67d seem to govern different behaviors in <i>D. bipectinata</i>, additional neurons detecting at least one of those compounds might be involved. These results underscore the complexity of chemical signaling in species recognition and raise intriguing questions about the evolutionary implications of pheromone detection pathways in <i>Drosophila</i> species.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-17DOI: 10.1007/s10886-024-01547-1
Asifur Rahman-Soad, Ludwig Skuras, Andreas Reinecke, Martti Varama, Monika Hilker
Pinus sylvestris trees are known to efficiently defend themselves against eggs of the herbivorous sawfly Diprion pini. Their direct defense against eggs is primable by prior exposure to the sex pheromones of this species and their indirect defense involves attraction of egg parasitoids by egg-induced pine needle odor. But it is unknown whether exposure of pine to D. pini sex pheromones also affects pine indirect defense against sawfly eggs. In this study, we investigated the influence of exposure of P. sylvestris trees to the sex pheromones of D. pini on indirect defense mediated by egg parasitoids. Behavioral assays with Closterocerus ruforum, a key parasitoid of sawfly eggs, revealed no significant attraction to odor from egg-free pines pre-exposed to pheromones. Chemical analyses of odor from egg-free pines showed no pheromone-induced change in the emission rates of the known key terpenoids promoting parasitoid attraction. Further comparative analyses of odor from egg-laden pines pre-exposed to the sex pheromones and of odor from egg-laden pines unexposed to pheromones neither revealed significant differences in the emission rates of terpenoids relevant for parasitoid attraction. The results suggest that a pheromone-induced or pheromone-primed, egg-induced pine indirect defense seems to be redundant in addition to the known pheromone-primable pine direct defense against the eggs and the known egg-inducible indirect defense.
众所周知,松树能有效地抵御食草锯螨 Diprion pini 的卵。它们对卵的直接防御是通过事先接触该物种的性信息素来实现的,间接防御则是通过卵引起的松针气味来吸引卵寄生虫。但是,松树暴露于 D. pini 的性信息素是否也会影响松树对锯螨卵的间接防御还不得而知。在这项研究中,我们调查了松树暴露于 D. pini 性信息素对卵寄生虫介导的间接防御的影响。对锯螨卵的主要寄生虫 Closterocerus ruforum 进行的行为试验表明,预先暴露于信息素的无卵松树的气味没有明显的吸引力。对无卵松树气味的化学分析显示,信息素对促进寄生虫吸引力的已知主要萜类化合物的释放率没有诱导性变化。对预先暴露于性信息素的含卵松树的气味和未暴露于信息素的含卵松树的气味进行进一步比较分析,也没有发现与寄生虫引诱有关的萜类化合物的释放率有显著差异。结果表明,除了已知的信息素诱导的松树对卵的直接防御和已知的卵诱导的间接防御外,信息素诱导或信息素引诱的卵诱导的松树间接防御似乎是多余的。
{"title":"Sawfly Sex Pheromones: Analysis of Their Impact on Pine Odor Attractive to Egg Parasitoids","authors":"Asifur Rahman-Soad, Ludwig Skuras, Andreas Reinecke, Martti Varama, Monika Hilker","doi":"10.1007/s10886-024-01547-1","DOIUrl":"https://doi.org/10.1007/s10886-024-01547-1","url":null,"abstract":"<p><i>Pinus sylvestris</i> trees are known to efficiently defend themselves against eggs of the herbivorous sawfly <i>Diprion pini</i>. Their direct defense against eggs is primable by prior exposure to the sex pheromones of this species and their indirect defense involves attraction of egg parasitoids by egg-induced pine needle odor. But it is unknown whether exposure of pine to <i>D. pini</i> sex pheromones also affects pine indirect defense against sawfly eggs. In this study, we investigated the influence of exposure of <i>P. sylvestris</i> trees to the sex pheromones of <i>D. pini</i> on indirect defense mediated by egg parasitoids. Behavioral assays with <i>Closterocerus ruforum</i>, a key parasitoid of sawfly eggs, revealed no significant attraction to odor from egg-free pines pre-exposed to pheromones. Chemical analyses of odor from egg-free pines showed no pheromone-induced change in the emission rates of the known key terpenoids promoting parasitoid attraction. Further comparative analyses of odor from egg-laden pines pre-exposed to the sex pheromones and of odor from egg-laden pines unexposed to pheromones neither revealed significant differences in the emission rates of terpenoids relevant for parasitoid attraction. The results suggest that a pheromone-induced or pheromone-primed, egg-induced pine indirect defense seems to be redundant in addition to the known pheromone-primable pine direct defense against the eggs and the known egg-inducible indirect defense.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1007/s10886-024-01544-4
Muhammad Aslam, Oldřich Nedvěd, John J. Sloggett
In this paper, we examine intraspecific variation in the quantity of alkaloid chemical defence in field collected individuals of the polymorphic ladybird beetle Adalia decempunctata (10-spot ladybird). Like its more widely studied relative Adalia bipunctata (2-spot ladybird), A. decempunctata possesses the alkaloids adaline and adalinine, which are, respectively, the major and minor alkaloids of A. bipunctata. We focused especially on alkaloid concentration in relation to colour pattern morph, sex, and the relationship between female and egg parameters. There was a marked sexual dimorphism in the balance of the two alkaloids, with adaline predominating in females and adalinine predominating in males: in males, on average, over 70% of total alkaloid was adalinine. Females had a lower proportion of adalinine (< 10%) than their eggs (> 15%) and relationships between egg alkaloid and female alkaloid or fecundity were weak or non-existent. Colour pattern morph had a borderline (although not) significant relationship with adaline concentration and total alkaloid concentration, which could be further explored with laboratory reared individuals. The sexual dimorphism in alkaloid content, which seems likely due to differences in synthesis, might be related to their relative costs to the two sexes and might provide insight into the evolution of alkaloid diversity in ladybirds.
{"title":"Intraspecific Variation in the Alkaloids of Adalia decempunctata (Coleoptera, Coccinellidae): Sex, Reproduction and Colour Pattern Polymorphism","authors":"Muhammad Aslam, Oldřich Nedvěd, John J. Sloggett","doi":"10.1007/s10886-024-01544-4","DOIUrl":"https://doi.org/10.1007/s10886-024-01544-4","url":null,"abstract":"<p>In this paper, we examine intraspecific variation in the quantity of alkaloid chemical defence in field collected individuals of the polymorphic ladybird beetle <i>Adalia decempunctata</i> (10-spot ladybird). Like its more widely studied relative <i>Adalia bipunctata</i> (2-spot ladybird), <i>A. decempunctata</i> possesses the alkaloids adaline and adalinine, which are, respectively, the major and minor alkaloids of <i>A. bipunctata</i>. We focused especially on alkaloid concentration in relation to colour pattern morph, sex, and the relationship between female and egg parameters. There was a marked sexual dimorphism in the balance of the two alkaloids, with adaline predominating in females and adalinine predominating in males: in males, on average, over 70% of total alkaloid was adalinine. Females had a lower proportion of adalinine (< 10%) than their eggs (> 15%) and relationships between egg alkaloid and female alkaloid or fecundity were weak or non-existent. Colour pattern morph had a borderline (although not) significant relationship with adaline concentration and total alkaloid concentration, which could be further explored with laboratory reared individuals. The sexual dimorphism in alkaloid content, which seems likely due to differences in synthesis, might be related to their relative costs to the two sexes and might provide insight into the evolution of alkaloid diversity in ladybirds.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-05DOI: 10.1007/s10886-024-01529-3
Jeremy Davis, Matthew Scott, Daniel Cook, Dale Gardner, Geoffrey Morse, Michael Grillo
Legumes are notorious for coevolutionary arms races where chemical defenses are employed to ward off herbivores-particularly insect seed predators. Locoweeds are legumes containing the toxic alkaloid swainsonine which can poison livestock, but its role as a deterrent for insects is unknown. Swainsonine is produced by the fungal endophyte Alternaria section Undifilum, and the chemical composition of the toxin has been well characterized. Despite this knowledge, the ecological roles and evolutionary drivers of swainsonine toxins in locoweeds remain uncertain. Here, we quantify swainsonine concentrations and herbivory levels in the hyper-diverse locoweed Astragalus lentiginosus to evaluate its role as an evolved chemical defense. We found that A. lentiginosus shows considerable variation in swainsonine concentrations according to variety, in particular showing presence/absence variation at both population and local geographic scales. Surprisingly, herbivory levels from presumed generalist insects emerging from fruits showed no correlation with swainsonine concentrations. Conversely, seed and fruit herbivory levels linked to specialist Acanthoscelides seed beetles increased with concentrations of swainsonine-suggesting a possible coevolutionary arms race. Our results highlight that variation in endophyte-produced toxin systems may not follow classical expectations for geographic variation and ecological roles of plant chemicals. We discuss the implications of these results on plant-endophytic toxin systems and coevolutionary dynamics more broadly, highlighting a considerable need for more research in these systems.
{"title":"Extensive Local Geographic Variation in Locoweed Toxin Produced by a Fungal Endophyte.","authors":"Jeremy Davis, Matthew Scott, Daniel Cook, Dale Gardner, Geoffrey Morse, Michael Grillo","doi":"10.1007/s10886-024-01529-3","DOIUrl":"https://doi.org/10.1007/s10886-024-01529-3","url":null,"abstract":"<p><p>Legumes are notorious for coevolutionary arms races where chemical defenses are employed to ward off herbivores-particularly insect seed predators. Locoweeds are legumes containing the toxic alkaloid swainsonine which can poison livestock, but its role as a deterrent for insects is unknown. Swainsonine is produced by the fungal endophyte Alternaria section Undifilum, and the chemical composition of the toxin has been well characterized. Despite this knowledge, the ecological roles and evolutionary drivers of swainsonine toxins in locoweeds remain uncertain. Here, we quantify swainsonine concentrations and herbivory levels in the hyper-diverse locoweed Astragalus lentiginosus to evaluate its role as an evolved chemical defense. We found that A. lentiginosus shows considerable variation in swainsonine concentrations according to variety, in particular showing presence/absence variation at both population and local geographic scales. Surprisingly, herbivory levels from presumed generalist insects emerging from fruits showed no correlation with swainsonine concentrations. Conversely, seed and fruit herbivory levels linked to specialist Acanthoscelides seed beetles increased with concentrations of swainsonine-suggesting a possible coevolutionary arms race. Our results highlight that variation in endophyte-produced toxin systems may not follow classical expectations for geographic variation and ecological roles of plant chemicals. We discuss the implications of these results on plant-endophytic toxin systems and coevolutionary dynamics more broadly, highlighting a considerable need for more research in these systems.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142132860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-27DOI: 10.1007/s10886-024-01542-6
Francisca Diana da Silva Araújo, Eddy Patricia Lopez Molano, Odalys García Cabrera, Carlos Henrique da Vasconcelos Fidelis, Gonçalo Amarante Guimarães Pereira, Marcos Nogueira Eberlin
Fungi of the genus Ceratocystis are aggressive tree pathogens that cause serious diseases in several crops around the world. Ceratocystis wilt disease caused by C. cacaofunesta has been shown to be responsible for severe reductions in cacao production. In this study, headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used in combination with chemometric analysis for monitoring volatile organic compounds (VOCs) released from C. cacaofunesta. Low-molecular-weight esters, alcohols, ketones, and sulphur compounds were identified in the liquid broth. Monitoring the volatile profile over five days of fungal growth revealed that the concentrations of alcohol and esters were inversely proportional. Acetate esters were responsible for the intense fruity aroma of the C. cacaofunesta culture produced within the first hours after fungal inoculation, which decreased over time, and are likely associated with the attraction of insect vectors to maintain the life cycle of the pathogen. PCA revealed that 3-methylbutyl acetate was the metabolite with the highest factor loading for the separation of the VOC samples after 4 h of fungal growth, whereas ethanol and 3-methylbutan-1-ol had the highest factor loadings after 96 and 120 h. 3-Methylbutan-1-ol is a phytotoxic compound that is likely associated with host cell death since C. cacaofunesta is a necrotrophic fungus. Fungal VOCs play important roles in natural habitats, regulating developmental processes and intra- and interkingdom interactions. This is the first report on the volatiles released by C. cacaofunesta.
Ceratocystis 属真菌是一种侵袭性树木病原体,会给世界各地的多种作物造成严重病害。由 C. cacaofunesta 引起的 Ceratocystis 枯萎病已被证明是可可产量严重下降的原因。在这项研究中,顶空固相微萃取(HS-SPME)与气相色谱-质谱联用仪(GC-MS)结合使用,并结合化学计量分析来监测 C. cacaofunesta 释放的挥发性有机化合物(VOCs)。在液体肉汤中鉴定出了低分子量酯类、醇类、酮类和硫化合物。对真菌生长五天内的挥发性物质进行监测后发现,醇和酯的浓度成反比。醋酸酯是 C. cacaofunesta 培养物在接种真菌后最初几小时内产生浓郁果香的原因,这种香味随着时间的推移而减少,可能与吸引昆虫载体以维持病原体的生命周期有关。PCA 显示,3-甲基丁基乙酸酯是真菌生长 4 小时后分离挥发性有机化合物样本时因子载荷最高的代谢物,而乙醇和 3-甲基丁-1-醇在 96 和 120 小时后的因子载荷最高。真菌挥发性有机化合物在自然栖息地中发挥着重要作用,可调节发育过程以及真菌内部和真菌之间的相互作用。这是首次报道 C. cacaofunesta 释放的挥发性有机化合物。
{"title":"Volatile Organic Compounds from Ceratocystis cacaofunesta, a Causal Agent of Ceratocystis Wilt of Cacao.","authors":"Francisca Diana da Silva Araújo, Eddy Patricia Lopez Molano, Odalys García Cabrera, Carlos Henrique da Vasconcelos Fidelis, Gonçalo Amarante Guimarães Pereira, Marcos Nogueira Eberlin","doi":"10.1007/s10886-024-01542-6","DOIUrl":"https://doi.org/10.1007/s10886-024-01542-6","url":null,"abstract":"<p><p>Fungi of the genus Ceratocystis are aggressive tree pathogens that cause serious diseases in several crops around the world. Ceratocystis wilt disease caused by C. cacaofunesta has been shown to be responsible for severe reductions in cacao production. In this study, headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used in combination with chemometric analysis for monitoring volatile organic compounds (VOCs) released from C. cacaofunesta. Low-molecular-weight esters, alcohols, ketones, and sulphur compounds were identified in the liquid broth. Monitoring the volatile profile over five days of fungal growth revealed that the concentrations of alcohol and esters were inversely proportional. Acetate esters were responsible for the intense fruity aroma of the C. cacaofunesta culture produced within the first hours after fungal inoculation, which decreased over time, and are likely associated with the attraction of insect vectors to maintain the life cycle of the pathogen. PCA revealed that 3-methylbutyl acetate was the metabolite with the highest factor loading for the separation of the VOC samples after 4 h of fungal growth, whereas ethanol and 3-methylbutan-1-ol had the highest factor loadings after 96 and 120 h. 3-Methylbutan-1-ol is a phytotoxic compound that is likely associated with host cell death since C. cacaofunesta is a necrotrophic fungus. Fungal VOCs play important roles in natural habitats, regulating developmental processes and intra- and interkingdom interactions. This is the first report on the volatiles released by C. cacaofunesta.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142072920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1007/s10886-024-01538-2
Kayleigh C Hauri, Anthony L Schilmiller, Elisabeth Darling, Amanda D Howland, David S Douches, Zsofia Szendrei
Plants defend themselves chemically against herbivory through secondary metabolites and phytohormones. Few studies have investigated how constitutive variation in secondary metabolites contributes to systemic herbivory response. We hypothesized that plants with lower constitutive defenses would induce a stronger phytohormone response to spatially separated herbivory than plants with high constitutive defense. We used growth chamber bioassays to investigate how aboveground herbivory by Colorado potato beetle (Leptinotarsa decemlineata, CPB) and belowground herbivory by northern root-knot nematode (Meloidogyne hapla, RKN) altered phytohormones and glycoalkaloids in roots and shoots of two lines of wild potato (Solanum chacoense). These lines had different constitutive levels of chemical defense, particularly leptine glycoalkaloids, which are only present in aboveground tissues. We also determined how these differences influenced the preference and performance of CPB. The susceptible wild potato line responded to aboveground damage by CPB through induction of jasmonic acid (JA) and OPDA. However, when challenged by both RKN and CPB, the susceptible line retained high levels of JA, but not OPDA. Beetles gained more mass after feeding on the susceptible line compared to the resistant line, but were not affected by nematode presence. Belowground, JA, JA-Isoleucine, and OPDA were higher in the resistant line compared to the susceptible line, and some compounds demonstrated response to local herbivory. In contrast, the susceptible line did not induce phytohormone defenses belowground. These findings allow us to predict that constitutive level of defense may influence the threshold of herbivory that may lead to plant-mediated effects on spatially separated herbivores.
{"title":"Constitutive Level of Specialized Secondary Metabolites Affects Plant Phytohormone Response to Above- and Belowground Herbivores.","authors":"Kayleigh C Hauri, Anthony L Schilmiller, Elisabeth Darling, Amanda D Howland, David S Douches, Zsofia Szendrei","doi":"10.1007/s10886-024-01538-2","DOIUrl":"https://doi.org/10.1007/s10886-024-01538-2","url":null,"abstract":"<p><p>Plants defend themselves chemically against herbivory through secondary metabolites and phytohormones. Few studies have investigated how constitutive variation in secondary metabolites contributes to systemic herbivory response. We hypothesized that plants with lower constitutive defenses would induce a stronger phytohormone response to spatially separated herbivory than plants with high constitutive defense. We used growth chamber bioassays to investigate how aboveground herbivory by Colorado potato beetle (Leptinotarsa decemlineata, CPB) and belowground herbivory by northern root-knot nematode (Meloidogyne hapla, RKN) altered phytohormones and glycoalkaloids in roots and shoots of two lines of wild potato (Solanum chacoense). These lines had different constitutive levels of chemical defense, particularly leptine glycoalkaloids, which are only present in aboveground tissues. We also determined how these differences influenced the preference and performance of CPB. The susceptible wild potato line responded to aboveground damage by CPB through induction of jasmonic acid (JA) and OPDA. However, when challenged by both RKN and CPB, the susceptible line retained high levels of JA, but not OPDA. Beetles gained more mass after feeding on the susceptible line compared to the resistant line, but were not affected by nematode presence. Belowground, JA, JA-Isoleucine, and OPDA were higher in the resistant line compared to the susceptible line, and some compounds demonstrated response to local herbivory. In contrast, the susceptible line did not induce phytohormone defenses belowground. These findings allow us to predict that constitutive level of defense may influence the threshold of herbivory that may lead to plant-mediated effects on spatially separated herbivores.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142055715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1007/s10886-024-01540-8
Jean-François Ferveur, Jérôme Cortot, Bernard Moussian, Claude Everaerts
In large groups of vertebrates and invertebrates, aggregation can affect biological characters such as gene expression, physiological, immunological and behavioral responses. The insect cuticle is covered with hydrocarbons (cuticular hydrocarbons; CHCs) which reduce dehydration and increase protection against xenobiotics. Drosophila melanogaster and D. simulans flies also use some of their CHCs as contact pheromones. In these two sibling species, males also produce the volatile pheromone 11-cis-Vaccenyl acetate (cVa). To investigate the effect of insect density on the production of CHCs and cVa we compared the level of these male pheromones in groups of different sizes. These compounds were measured in six lines acclimated for many generations in our laboratory - four wild-type and one CHC mutant D. melanogaster lines plus one D. simulans line. Increasing the group size substantially changed pheromone amounts only in the four D. melanogaster wild-type lines. To evaluate the role of laboratory acclimation in this effect, we measured density-dependent pheromonal production in 21 lines caught in nature after 1, 12 and 25 generations in the laboratory. These lines showed varied effects which rarely persisted across generations. Although increasing group size often affected pheromone production in laboratory-established and freshly-caught D. melanogaster lines, this effect was not linear, suggesting complex determinants.
{"title":"Population Density Affects Drosophila Male Pheromones in Laboratory-Acclimated and Natural Lines.","authors":"Jean-François Ferveur, Jérôme Cortot, Bernard Moussian, Claude Everaerts","doi":"10.1007/s10886-024-01540-8","DOIUrl":"https://doi.org/10.1007/s10886-024-01540-8","url":null,"abstract":"<p><p>In large groups of vertebrates and invertebrates, aggregation can affect biological characters such as gene expression, physiological, immunological and behavioral responses. The insect cuticle is covered with hydrocarbons (cuticular hydrocarbons; CHCs) which reduce dehydration and increase protection against xenobiotics. Drosophila melanogaster and D. simulans flies also use some of their CHCs as contact pheromones. In these two sibling species, males also produce the volatile pheromone 11-cis-Vaccenyl acetate (cVa). To investigate the effect of insect density on the production of CHCs and cVa we compared the level of these male pheromones in groups of different sizes. These compounds were measured in six lines acclimated for many generations in our laboratory - four wild-type and one CHC mutant D. melanogaster lines plus one D. simulans line. Increasing the group size substantially changed pheromone amounts only in the four D. melanogaster wild-type lines. To evaluate the role of laboratory acclimation in this effect, we measured density-dependent pheromonal production in 21 lines caught in nature after 1, 12 and 25 generations in the laboratory. These lines showed varied effects which rarely persisted across generations. Although increasing group size often affected pheromone production in laboratory-established and freshly-caught D. melanogaster lines, this effect was not linear, suggesting complex determinants.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142055717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1007/s10886-024-01539-1
Cindy Perkovich, Anthony L Witcher, Jason B Oliver, Karla M Addesso
Flatheaded borers (FHB; Chrysobothris spp.), are woodboring-beetles that lay their eggs in the bark and cambium of deciduous trees in North America. Females often target stressed host-plants for oviposition. The reason why is unknown; however, stressed plants often suffer various induced phytochemical changes that may enhance larval infestation success depending on the stressor such as induced upregulation of defenses, reallocation of nutrients, and changes to volatile organic compound (VOC) emissions. To understand attraction of FHB to specific stress-induced changes, we analyzed phytochemical changes associated with stress treatments and attractiveness maple trees to FHB. Trees were stressed by: (1) chemical stress (pelargonic acid herbicide), (2) physical stress (physically removing leaves), and (3) physical stress (removing portions of bark near the root crown). After reflush of defoliated trees, bark tissues where FHB larvae feed were analyzed for nutritional changes (carbon and nitrogen), anti-nutritive changes (polyphenols and tannins) and emissions of foliar VOCs. At the end of the growing season, trees were assessed for FHB larval presence and oviposition attempts. There were more larvae and oviposition attempts on trees stressed by herbicide application. Compared to other treatments, herbicide-stressed trees had greater nitrogen and total polyphenol concentrations. Greater nitrogen may play a role in the fitness of feeding larvae, and the greater polyphenol concentration may stimulate female oviposition in the herbicide stressed trees. Females may be able to locate the herbicide-stressed trees by using volatile cues such as increases in limonene, α-farnesene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and hexenyl acetate.
{"title":"Herbicide Stress Inducesbeetle Oviposition on Red Maples.","authors":"Cindy Perkovich, Anthony L Witcher, Jason B Oliver, Karla M Addesso","doi":"10.1007/s10886-024-01539-1","DOIUrl":"https://doi.org/10.1007/s10886-024-01539-1","url":null,"abstract":"<p><p>Flatheaded borers (FHB; Chrysobothris spp.), are woodboring-beetles that lay their eggs in the bark and cambium of deciduous trees in North America. Females often target stressed host-plants for oviposition. The reason why is unknown; however, stressed plants often suffer various induced phytochemical changes that may enhance larval infestation success depending on the stressor such as induced upregulation of defenses, reallocation of nutrients, and changes to volatile organic compound (VOC) emissions. To understand attraction of FHB to specific stress-induced changes, we analyzed phytochemical changes associated with stress treatments and attractiveness maple trees to FHB. Trees were stressed by: (1) chemical stress (pelargonic acid herbicide), (2) physical stress (physically removing leaves), and (3) physical stress (removing portions of bark near the root crown). After reflush of defoliated trees, bark tissues where FHB larvae feed were analyzed for nutritional changes (carbon and nitrogen), anti-nutritive changes (polyphenols and tannins) and emissions of foliar VOCs. At the end of the growing season, trees were assessed for FHB larval presence and oviposition attempts. There were more larvae and oviposition attempts on trees stressed by herbicide application. Compared to other treatments, herbicide-stressed trees had greater nitrogen and total polyphenol concentrations. Greater nitrogen may play a role in the fitness of feeding larvae, and the greater polyphenol concentration may stimulate female oviposition in the herbicide stressed trees. Females may be able to locate the herbicide-stressed trees by using volatile cues such as increases in limonene, α-farnesene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and hexenyl acetate.</p>","PeriodicalId":15346,"journal":{"name":"Journal of Chemical Ecology","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142055716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}