Release of male courtship display in Periplaneta americana: evidence for female contact sex pheromone

Male American cockroaches (Periplaneta americana) are attracted to virgin females by volatile sex pheromones. After antennal contact with the female they turn through 180° and spread their wings in courtship display. A chemical contact stimulus releasing male courtship is demonstrated in the female cuticle. Experiments with standardized olfactory stimulation by volatile sex pheromones revealed that the contact stimulus is sex-specific and species-specific. It can be washed off the cuticle with non-polar solvents and was successfully transferred to glass dummies. However, it is not effective in the absence of volatile sex pheromones. Thus volatile sex pheromones are responsible for male attraction and sexual motivation, while mate recognition is accomplished through the contact pheromone.     

天牛成虫信息素及嗅觉感受机制研究进展

评述了天牛成虫信息素及嗅觉感受机制的研究进展。天牛雌、雄成虫均可释放性信息素,迄今已对31种天牛的性信息素进行了研究,其中完成组分鉴定的有13种。天牛性信息素包括长距离、短距离和接触性信息素3种类型。天牛性信息素存在变异现象,同种天牛分布在不同地区,其性信息素组分之间存在差异。触角是天牛感受性信息素的主要器官,也是判别成虫通讯方式的形态指标,性信息素发达的种类其触角常具显著的性二型现象。天牛利用寄主信息素（如萜烯类、醇类和酯类）寻找寄主。性信息素和寄主信息素在林间复合使用可提高诱捕率。天牛信息素还包括异种信息素、忌避信息素和产卵干扰素,能够提高天牛寄主定位效率。天牛触角嗅觉感受的神经细胞（RNs）有3类,气味信息经神经细胞群传输至中枢神经系统,神经信号按标记路线或交叉纤维样式输导。天牛气味结合蛋白（OBP）方面的研究尚未见报道。     

Insect pheromones

The evidence for intraspecies chemical communication in insects is reviewed, with emphasis on those studies where known organic compounds have been implicated. These signal-carrying chemicals are known as pheromones. There are two distinct types of pheromones, releasers and primers. Releaser pheromones initiate immediate behavioral responses in insects upon reception, while primer pheromones cause physiological changes in an animal that ultimately result in a behavior response. Chemically identified releaser pheromones are of three basic types: those which cause sexual attraction, alarm behavior, and recruitment. Sex pheromones release the entire repertoire of sexual behavior. Thus a male insect may be attracted to and attempt to copulate with an inanimate object that has sex pheromone on it. It appears that most insects are rather sensitive and selective for the sex pheromone of their species. Insects show far less sensitivity and chemospecificity for alarm pheromones. Alarm selectivity is based more on volatility than on unique structural features. Recruiting pheromones are used primarily in marking trails to food sources. Terrestrial insects lay continuous odor trails, whereas bees and other airborne insects apply the substances at discrete intervals. It appears that a complex pheromone system is used by the queen bee in the control of worker behavior. One well-established component of this system is a fatty acid, 9-ketodecenoic acid, produced by the queen and distributed among the workers. This compound prevents the development of ovaries in the workers and inhibits their queen-rearing activities. In addition, the same compound is used by virgin queen bees as a sex attractant.     

Pheromonal communication involved in courtship behavior in Diptera

Sex pheromones are known for many dipteran species and play an important role in courtship behavior, together with visual, tactile, acoustic and other factors. Pheromones for a number of dipterans have been recently identified. This survey covers a number of species in all the families that have been studied. The review discusses diverse courtship behaviors in Diptera, with a special focus on the sex pheromones involved. In the Nematocera suborder, pheromones are volatile components, which act at a distance. They are derived from short-chain alkanes with acetoxy groups (Cecidomyidae) or terpenes (Psychodidae). In the Cyclorrhapha, pheromones may be volatile, derived from alkanes (Tephritidae) or terpenes (Agromyzidae), or non-volatile, unsaturated or methyl-branched hydrocarbons, which act by contact (the other subgenera). The behavioral roles and regulation of these pheromones are described, and their importance in species recognition is discussed.     

蛾类性信息素生物合成途径及其调控

蛾类通过产生和识别物种特异性性信息素来引发后续交配行为,因此它在两性交配行为中至关重要.它们具有不同碳链长度、末端官能团、不同双键位置和构型等化学结构特征,本文详细讨论了不同蛾类性信息素的合成途径以及催化每一步反应的相关酶系,列举了15种夜蛾科不同亚科常见物种的性信息素组分及其比例,总结了产生特定比例性信息素的可能原因,查阅了夜蛾科不同物种已经鉴别的性信息素,并按照不同亚科、不同官能团和碳链长度对其进行分类,归纳了同一物种及其亲缘物种性信息素组分和比例的变异,总结了产生变异的分子机理,讨论了性信息素变异和物种进化的关系.最后以生物合成激活神经肽(PBAN)为主, 介绍了其调控途径和机制.本文旨在以不同的蛾类性信息素合成途径为线索,从共有合成途径出发深入了解其规律和共性,从特异合成途径出发探究物种间的进化和变异,展望未来的研究方向及其应用.     

Spider sex pheromones: emission, reception, structures, and functions

Spiders and their mating systems are useful study subjects with which to investigate questions of widespread interest about sexual selection, pre- and post-copulatory mate choice, sperm competition, mating strategies, and sexual conflict. Conclusions drawn from such studies are broadly applicable to a range of taxa, but rely on accurate understanding of spider sexual interactions. Extensive behavioural experimentation demonstrates the presence of sex pheromones in many spider species, and recent major advances in the identification of spider sex pheromones merit review. Synthesised here are the emission, transmission, structures, and functions of spider sex pheromones, with emphasis on the crucial and dynamic role of sex pheromones in female and male mating strategies generally. Techniques for behavioural, chemical and electrophysiological study are summarised, and I aim to provide guidelines for incorporating sex pheromones into future studies of spider mating. In the spiders, pheromones are generally emitted by females and received by males, but this pattern is not universal. Female spiders emit cuticular and/or silk-based sex pheromones, which can be airborne or received via contact with chemoreceptors on male pedipalps. Airborne pheromones primarily attract males or elicit male searching behaviour. Contact pheromones stimulate male courtship behaviour and provide specific information about the emitter's identity. Male spiders are generally choosy and are often most attracted to adult virgin females and juvenile females prior to their final moult. This suggests the first male to mate with a female has significant advantages, perhaps due to sperm priority patterns, or mated female disinterest. Both sexes may attempt to control female pheromone emission, and thus dictate the frequency and timing of female mating, reflecting the potentially different costs of female signalling and/or polyandry to both sexes. Spider sex pheromones are likely to be lipids or lipid soluble, may be closely related to primary metabolites, and are not necessarily species specific, although they can still assist with species recognition. Newer electrophysiological techniques coupled with chemical analyses assist with the identification of sex pheromone compounds. This provides opportunities for more targeted behavioural experimentation, perhaps with synthetic pheromones, and for theorising about the biosynthesis and evolution of chemical signals generally. Given the intriguing biology of spiders, and the critical role of chemical signals for spiders and many other animal taxa, a deeper understanding of spider sex pheromones should prove productive.     

Social behavior and pheromonal communication in reptiles

The role of pheromones in orchestrating social behaviors in reptiles is reviewed. Although all reptile orders are examined, the vast majority of the literature has dealt only with squamates, primarily snakes and lizards. The literature is surprisingly large, but most studies have explored relatively few behaviors. The evolution of chemical signaling in reptiles is discussed along with behaviors governed by pheromones including conspecific trailing, male-male agonistic interactions, sex recognition and sex pheromones, and reptilian predator recognition. Nonreptilian prey recognition by chemical cues was not reviewed. The recent literature has focused on two model systems where extensive chemical ecology studies have been conducted: the reproductive ecology of garter snakes and the behavioral ecology of Iberian lacertid lizards. In these two systems, enough is known about the chemical constituents that mediate behaviors to explore the evolution of chemical signaling mechanisms that affect life history patterns. In addition, these models illuminate natural and sexual selection processes which have lead to complex chemical signals whose different components and concentrations provide essential information about individuals to conspecifics. Reptiles provide excellent candidates for further studies in this regard not only in squamates, but also in the orders where little experimental work has been conducted to date.     

金龟子化学通讯与信息化学物质

本文综述了金龟子的化学通讯与信息化学物质研究与应用的新进展,重点评述了丽金龟科和鳃金龟科性信息素的鉴定与化学结构。迄今,已有14种金龟子的性信息素被鉴定,还有一些金龟子的聚集信息素和两性引诱剂被报道。对金龟子性信息素、聚集信息素和引诱剂等信息化学物质的应用也作了概述。     

Alkenyl sex pheromone analogs in the hemolymph of an arctiid Eilema japonica and several non-arctiid moths

The majority of moth species utilize compounds derived from de novo synthesized fatty acids as their sex pheromones (type I). In contrast, species belonging to two recently diverged moth families, Arctiidae and Geometridae, utilize alkenes and their epoxides, which are derived from dietary essential fatty acids (EFAs), as their sex pheromones (type II). In the latter species, EFAs are considered to be converted into alkenes, often after chain elongation, in specialized cells called oenocytes. These alkenes are transported through the hemolymph to the pheromone gland, from which they are secreted with or without further modifications. We confirmed that the appearance of EFA-derived alkenes in the hemolymph was closely associated with the completion of pheromone gland formation in an arctiid moth Eilema japonica. Analyses of the hemolymph of several moth species utilizing type-I sex pheromones demonstrated the occurrence of (Z,Z,Z)-3,6,9-tricosatriene (T23), a typical type-II component, in the hemolymph of a noctuid Mamestra brassicae and two crambids Ostrinia furnacalis and Ostrinia scapulalis. Our results demonstrated that moths utilizing type-I pheromones have the ability to synthesize type-II sex pheromones, and suggested that recently diverged groups of moths may have secondarily exploited EFA-derived alkenes as sex pheromones.     

Molecular mechanisms underlying sex pheromone production in the silkmoth, Bombyx mori: characterization of the molecular components involved in bombykol biosynthesis

Many species of female moths produce sex pheromones to attract conspecific males. To date, sex pheromones from more than 570 moth species have been chemically identified. Most moth species utilize Type I pheromones that consist of straight-chain compounds 10-18 carbons in length with a functional group of a primary alcohol, aldehyde, or acetate ester and usually with several double bonds. In contrast, some moth species use unsaturated hydrocarbons or hydrocarbon epoxides, classified as Type II lepidopteran pheromones, as sex pheromones. Studies over the past three decades have demonstrated that female moths usually produce sex pheromones as multi-component blends where the ratio of the individual components is precisely controlled, thus making it possible to generate species-specific pheromone blends. As for the biosynthesis of Type I pheromones, it is well established that they are de novo synthesized in the pheromone gland (PG) through modifications of fatty acid biosynthetic pathways. However, as many of the molecular components within the PG cells (i.e., enzymes, proteins, and small regulatory molecules) have not been functionally characterized, the molecular mechanisms underlying sex pheromone production in PG cells remain poorly understood. To address this, we have recently characterized some of the molecules involved in the biosynthesis of the sex pheromone bombykol in the silkmoth, Bombyx mori. Characterization of these, and other, key molecules will facilitate our understanding of the precise mechanisms underlying lepidopteran sex pheromone production.     

蛾类性信息素研究进展

蛾类是昆虫性信息素中研究较多的类群,已有565种的性信息素成份被鉴定,其相关研究在害虫监测和防治上得到实际应用的同时,已涉及到生态、生化、遗传等诸多方面,特别是在物种多样性的化学表达及物种的生殖隔离现象的分子水平的表达上,提供了研究的典范。本文将介绍蛾类性信息素的多样性、性信息素化学结构鉴定、微量成分的作用、合成性信息素的利用、性信息素生物合成酶、性信息素生产的调节机制及性信息素的感受机制等方面的研究现状和存在的问题。     

木蠹蛾性信息素研究的进展

综述了木蠹蛾性信息素研究及在综合防治措施中应用的最新进展,重点评述了木蠹蛾性信息素的结构鉴定与化学结构。至今有4种木蠹蛾的性信息素被鉴定,另外还筛选出2种木蠹蛾的性诱剂。在我国,对木蠹蛾的防治,应采取化学防治、生物防治及使用人工合成性信息素或性诱剂诱捕法和迷向法综合防治措施。     

Sexual agglutination in budding yeasts: structure, function, and regulation of adhesion glycoproteins.

The sexual agglutinins of the budding yeasts are cell adhesion proteins that promote aggregation of cells during mating. In each yeast species, complementary agglutinins are expressed by cells of opposite mating type that interact to mediate aggregation. Saccharomyces cerevisiae alpha-agglutinin and its analogs from other yeasts are single-subunit glycoproteins that contain N-linked and O-linked oligosaccharides. The N-glycosidase-sensitive carbohydrate is not necessary for activity. The proposed binding domain of alpha-agglutinin has features characteristic of the immunoglobulin fold structures of cell adhesion proteins of higher eukaryotes. The C-terminal region of alpha-agglutinin plays a role in anchoring the glycoprotein to the cell surface. The S. cerevisiae alpha-agglutinin and its analogs from other species contain multiple subunits; one or more binding subunits, which interact with the opposite agglutinin, are disulfide bonded to a core subunit, which mediates cell wall anchorage. The core subunits are composed of 80 to 95% O-linked carbohydrate. The binding subunits have less carbohydrate, and both carbohydrate and peptide play roles in binding. The alpha-agglutinin and alpha-agglutinin genes from S. cerevisiae have been cloned and shown to be regulated by the mating-type locus, MAT, and by pheromone induction. The agglutinins are necessary for mating under conditions that do not promote cell-cell contact. The role of the agglutinins therefore is to promote close interactions between cells of opposite mating type and possibly to facilitate the response to phermone, thus increasing the efficiency of mating. We speculate that they mediate enhanced response to sex pheromones by providing a synapse at the point of cell-cell contact, at which both pheromone secretion and cell fusion occur.     

Does the scent of a potential mate prevent the resorption of oocytes by apoptosis in Nauphoeta cinerea?

Abstract  We expect organisms to have evolved mechanisms to gather and use the information available within their environments, to steer resource investment decisions toward the traits that will give the greatest fitness returns. Pheromones are social signals, a common purpose of which is to act as indicators of mate presence. Consequently, pheromones have the potential to act as signals to increase or maintain reproductive investment over that of competing life-history traits. In the cockroach, Nauphoeta cinerea (Oliver), females pay costs of maintaining investment in reproduction when there are no males, and males produce pheromones that are known to effect female reproductive outcomes. Whether the pheromones have an influence on resource physiology is unknown. We subjected newly eclosed females to either a synthetic blend of male pheromones or control. We dissected females at 7, 12, 17 or 22 days. We measured apoptosis levels and size of all oocytes within the vitellerium, and measured dry fat body mass. Synthetic male pheromone blend did not have an effect on any measure of female reproductive or somatic resource physiology. Although negative results are always problematic, the success of the synthetic pheromone method in the past suggests that females may be insensitive to male pheromones in the pre-oviposition period, and may rely on mating stimulus rather than pheromone as the cue for oocyte maintenance and growth. Previous studies reporting effects of male pheromones on female reproduction suggest that the period of pheromone sensitivity may be between mating and birth.     

天牛性信息素、引诱植物和植物性引诱剂的研究与应用

由于目前所拥有的各种天牛防治方法都难以获得理想的防治效果,研发新型天牛控制技术势在必行。其中利用引诱剂是最具潜力的研究领域之一。对天牛的性信息素、引诱植物和植物性引诱剂3个方面的研究及应用作了综述。天牛雌、雄成虫均可释放性信息素进行两性间的通讯联系。天牛性信息素的分泌部位因天牛种类不同而存在着差异。雄、雌成虫触角上均有感受性信息素的感受器,但报道较多的是雄虫感受器。迄今已鉴定出13种天牛性信息素的化学结构。一般而言,天牛成虫的嗜食树种,对天牛具有较强的引诱作用,可作为诱饵树种使用。寄主植物的某些挥发性物质对天牛成虫也有独特的引诱效果。除此之外,对天牛性信息素、引诱植物和植物性引诱剂研究与应用中存在的困难也进行了讨论,并对它们的应用前景做了展望。     

Male Aggregation Pheromones Inhibit Ideal Free Habitat Selection in Red Flour Beetles (<Emphasis Type="Italic">Tribolium castaneum</Emphasis>)

The ideal free distribution (IFD) predicts that individuals should be distributed between habitats in proportion to habitat suitability such that mean fitness is equal in each habitat. The IFD is useful in studies examining habitat selection, yet its key assumptions are often violated and the expected IFDs are not consistently detected. While the use of aggregation pheromones by insects is expected to evolve in systems that experience positive density dependence (Allee effect), through a series of experiments we test the hypothesis that aggregation pheromones may limit the ability of individuals to achieve an IFD. Using red flour beetles (Tribolium castaneum), we specifically test the prediction that beetles in groups with an equal sex ratio or in the presence of an artificial aggregation pheromone will deviate from an IFD, whereas female-only groups will achieve an IFD. We also test the hypothesis that aggregation pheromones evolved to promote Allee effects by testing the prediction that beetle fitness will show positive density dependence at low densities. Consistent with our first hypothesis, female groups achieved an IFD, while mixed sex groups and females in the presence of an aggregation pheromone in the low food habitat under-matched the IFD. We found no evidence of Allee effects at low density, but we did find evidence of strong negative density dependence. We demonstrate that the use of aggregation pheromones may negatively impact a population’s ability to achieve an IFD and cast doubt on the hypothesis that male aggregation pheromones evolve to promote Allee effects.     

The male sex pheromone of the butterfly Bicyclus anynana: towards an evolutionary analysis

Background

Female sex pheromones attracting mating partners over long distances are a major determinant of reproductive isolation and speciation in Lepidoptera. Males can also produce sex pheromones but their study, particularly in butterflies, has received little attention. A detailed comparison of sex pheromones in male butterflies with those of female moths would reveal patterns of conservation versus novelty in the associated behaviours, biosynthetic pathways, compounds, scent-releasing structures and receiving systems. Here we assess whether the African butterfly Bicyclus anynana, for which genetic, genomic, phylogenetic, ecological and ethological tools are available, represents a relevant model to contribute to such comparative studies.

Methodology/Principal Findings

Using a multidisciplinary approach, we determined the chemical composition of the male sex pheromone (MSP) in the African butterfly B. anynana, and demonstrated its behavioural activity. First, we identified three compounds forming the presumptive MSP, namely (Z)-9-tetradecenol (Z9-14:OH), hexadecanal (16:Ald ) and 6,10,14-trimethylpentadecan-2-ol (6,10,14-trime-15-2-ol), and produced by the male secondary sexual structures, the androconia. Second, we described the male courtship sequence and found that males with artificially reduced amounts of MSP have a reduced mating success in semi-field conditions. Finally, we could restore the mating success of these males by perfuming them with the synthetic MSP.

Conclusions/Significance

This study provides one of the first integrative analyses of a MSP in butterflies. The toolkit it has developed will enable the investigation of the type of information about male quality that is conveyed by the MSP in intraspecific communication. Interestingly, the chemical structure of B. anynana MSP is similar to some sex pheromones of female moths making a direct comparison of pheromone biosynthesis between male butterflies and female moths relevant to future research. Such a comparison will in turn contribute to understanding the evolution of sex pheromone production and reception in butterflies.     

Repellent function of male pheromones in the red-spotted newt

Pheromones act as attractants and sexual stimulants in most vertebrates. For example, in red-spotted newts, Notophthalmus viridescens, female pheromones attract males, and male pheromones increase female receptivity. However, no studies have determined whether male vertebrates produce a pheromone that repels competing males. Through a series of olfactory mate selection tests, we found that sexually motivated male red-spotted newts produce a pheromone that functions to repel other approaching males. Our finding is the first report of a repelling function for pheromones in male vertebrates. The pheromones may act to increase both the sender's and receiver's mating success when the operational sex ratio (OSR) is male biased.     

Effect of a neuroendocrine factor on sex pheromone biosynthesis in the tomato looper,Chrysodeixis chalcites (Lepidoptera: Noctuidae)

The presence of a pheromone biosynthesis activating neurohormone in the head gandlia, and its effect on the sex phermone biosynthetic pathway, were investigated in the tomato looper, Chrysodeixis chalcites (Esper). Comparison of pheromone components and precursor levels in the presence and absence of the factor was performed using untreated, ligated and ligated and injected virgin females. Pheromone glands of treated and untreated moths were extracted and analyzed by capillary gas chromatography for their most abundant pheromone components, (Z)-7-dodecenyl acetate and (Z)-9-tetradecenyl acetate, and the putative biosynthetic precursors hexadecanoate, (Z)-11-hexadecenoate, (Z)-9-tetradecenoate and (Z)-7-dodecenoate. Comparison of the amounts of the pheromone and precursor components in the three groups of females indicated that a neuroendocrine factor is involved in the regulation of the pheromone biosynthesis in C. chalcites. Lack of such a factor resulted in a marked decrease of the sex pheromone components as well as the three unsaturated putative biosynthetic precursors. However, no decrease was observed in the content of palmitoate, suggesting that the Δ11 desaturation step is affected by the neuroendocrine factor. Injection of head ganglia extracts into ligated females resulted in a recovery of unsaturated precursor and phermone content. Both male and female head ganglia were found to contain a sex pheromone biosynthesis regulatory factor. However, the stimulatory pattern of the factor from the two sexes was different, suggesting that the two factors are quantitatively and/or qualitatively distinct.     

昆虫性信息素微胶囊的研究进展

微胶囊是应用昆虫性信息素进行害虫治理的主要剂型之一。文章对昆虫性信息素微胶囊常用的制备方法进行总结,并介绍其在害虫控制方面的应用进展,探讨昆虫性信息素微胶囊制备及其田间应用效果的影响因子,并对今后昆虫性信息素微胶囊的发展作了展望。