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BACKGROUND: Populations of the plant pathogenic fungus Verticillium dahliae display a complex and rich genetic diversity, yet the existence of sexual reproduction in the fungus remains contested. As pivotal genes, MAT genes play a crucial role in regulating cell differentiation, morphological development, and mating of compatible cells. However, the functions of the two mating type genes in V. dahliae, VdMAT1-1-1, and VdMAT1-2-1, remain poorly understood. RESULTS: In this study, we confirmed that the MAT loci in V. dahliae are highly conserved, including both VdMAT1-1-1 and VdMAT1-2-1 which share high collinearity. The conserved core transcription factor encoded by the two MAT loci may facilitate the regulation of pheromone precursor and pheromone receptor genes by directly binding to their promoter regions. Additionally, peptide activity assays demonstrated that the signal peptide of the pheromone VdPpg1 possessed secretory activity, while VdPpg2, lacked a predicted signal peptide. Chemotactic growth assays revealed that V. dahliae senses and grows towards the pheromones FO-a and FO-α of Fusarium oxysporum, as well as towards VdPpg2 of V. dahliae, but not in response to VdPpg1. The findings herein also revealed that VdMAT1-1-1 and VdMAT1-2-1 regulate vegetative growth, carbon source utilization, and resistance to stressors in V. dahliae, while negatively regulating virulence. CONCLUSIONS: These findings underscore the potential roles of VdMAT1-1-1 and VdMAT1-2-1 in sexual reproduction and confirm their involvement in various asexual processes of V. dahliae, offering novel insights into the functions of mating type genes in this species.

Knowledge of insect pest ecology and biology is important for maximizing crop protection and reducing crop losses. Currently, we lack an efficient control program for the cocoa mirid Sahlbergella singularis Haglund (Hemiptera: Miridae), the principal insect pest of cocoa in West and Central Africa. A 2-yr study was conducted in 11 plantations across Ayos and Konye, two of the largest cocoa growing areas of Cameroon. We evaluated the effects of mirid sex pheromone and climatic variations on mirid population dynamics and their associated cocoa damage. Sex pheromone traps caught 1.5-fold higher mirids in Ayos than in Konye, with more overall counts in 2015 than in 2016. Cocoa pod counts were also significantly higher in 2015 than in 2016 and were negatively correlated with temperature and relative humidity. In both localities, mirid populations and associated cocoa pod damage were suppressed in plantations where sex pheromone traps were used. Damage incidence was positively correlated with mirid counts, confirming that the cocoa pod is the preferential site for mirid feeding and reproduction. As such, damage incidence could be used as proxy for comparative mirid population level due to the mirid's cryptic habit. Of the recorded weather variables, only relative humidity was correlated (negatively) with damage severity. Our data on the relationships between damage caused by mirids and their population dynamics and sex pheromone trap catches suggest that an effective control strategy using mass trapping could be developed for mirid management in cocoa plantations.

Studies of adaptive radiations have played a central role in our understanding of reproductive isolation. Yet the focus has been on human-biased visual and auditory signals, leaving gaps in our knowledge of other modalities. To date, studies on chemical signals in adaptive radiations have focused on systems with multimodal signalling, making it difficult to isolate the role chemicals play in reproductive isolation. In this study we examine the use of chemical signals in the species recognition and adaptive radiation of Hawaiian Tetragnatha spiders by focusing on entire communities of co-occurring species, and conducting behavioural assays in conjunction with chemical analysis of their silks using gas chromatography-mass spectrometry. Male spiders significantly preferred the silk extracts of conspecific mates over those of sympatric heterospecifics. The compounds found in the silk extracts, long chain alkyl methyl ethers, were remarkably species-specific in the combination and quantity. The differences in the profile were greatest between co-occurring species and between closely related sibling species. Lastly, there were significant differences in the chemical profile between two populations of a particular species. These findings provide key insights into the role chemical signals play in the attainment and maintenance of reproductive barriers between closely related co-occurring species.

The blister beetle Epicauta atomaria (Germar) (Coleoptera: Meloidae) is a phytophagous pest of various agricultural crops, especially in Amaranthaceae, Solanaceae, and Fabaceae. Currently, this insect is managed through the spraying of synthetic insecticides that cause serious human health and environmental damage. To reduce the use of synthetic insecticides, the integrated pest management (IPM) programs for other crop pests rely on the use of semiochemical compounds, such as pheromones, kairomones, and allomones, to manipulate the insects' behavior to prevent crop damage. However, studies on semiochemical compounds related to E. atomaria have never been carried out. For this reason, the aim of this study was to explore the chemical communication of E. atomaria. This includes the existence of (i) a sex and/or an aggregation pheromone, (ii) attractant volatile kairomones from host plants, and (iii) repellent volatile allomones from non‐host plants. Tests were carried out using olfactometers and an experimental arena. First, olfactometer tests failed to show the existence of volatile sex and/or aggregation pheromones of these insects. Second, olfactometer and experimental arena tests failed to demonstrate attraction of E. atomaria via volatile kairomonal compounds from host plants (chard, bell pepper, and cock's‐eggs). However, olfactometer tests showed that non‐host plants of E. atomaria (thyme and lavender) emit allomonal volatile compounds with repellent activity. This work represents a first step toward the elucidation of the chemical ecology of E. atomaria and suggests that volatiles from non‐host plants help shape the host preferences of these insects. Those volatiles could be used as a "push" component in a "push–pull" strategy against this pest. [ABSTRACT FROM AUTHOR]

Death feigning is hypothesized to be an anti-predator behavior in which prey is temporarily immobilized in response to external stimuli. While death feigning may be an effective predator-defense strategy, there may be trade-offs in terms of energy and time for finding food and/or mating. The duration of death feigning is regulated by the balance of various selection pressures, and its duration is influenced by many internal and environmental factors. However, little is known about the factors that influence arousal from death-feigning behavior. Sex pheromones are important semiochemicals that affect reproductive success and may influence the duration of death-feigning behavior. In this study, we aimed to investigate the effects of sex pheromones on the death-feigning behavior of the sweet potato weevil (Cylas formicarius) by conducting laboratory experiments. The results showed that males had a significantly shorter death-feigning duration in the presence of sex pheromones because it aroused them from their death-feigning behavior, but females were unaffected. This is the first study to show that sex pheromones alter death-feigning behavior. The results of this study elucidate the factors influencing predator-avoidance behavior and reveal the impact of death-feigning behavior on prey reproduction under predation pressure. [ABSTRACT FROM AUTHOR]

Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) is a quarantine pest for certain export markets due to its phytosanitary status in affected crops in sub‐Saharan Africa, including citrus. Consequently, there is a zero‐tolerance policy for T. leucotreta in export markets. In South Africa, an integrated pest management strategy, incorporating a systems approach is used to achieve complete control of T. leucotreta. Preharvest management is multi‐faceted, including reliance on sex pheromone tools such as monitoring, attract‐and‐kill, mating disruptions, and sterile insect technique (SIT). Geographically isolated populations of T. leucotreta occur in South Africa, and there is speculation concerning the possible loss of sexual communication between these isolated populations, thereby compromising the efficiency of sex pheromone tools. To investigate this possibility, we collected samples from five geographically isolated populations of T. leucotreta and a population used for SIT in South Africa. These were subjected to sexual attraction trials under choice and no‐choice scenarios in a semi‐natural environment. Results of the choice tests revealed that males of each population preferred their corresponding population females, except irradiated males. However, when we deprived males of their preferred females, these preferences dissipated, and they were equally attracted to females from all populations. These results indicate that local adaptation and other selection forces in contrasting environments are important in sexual communication and selection in T. leucotreta but do not necessarily prevent recognition of sexual signals and attraction between geographically isolated populations. These findings are crucial for area‐wide IPM and precision control of T. leucotreta. [ABSTRACT FROM AUTHOR]

Females' ability to select mates that can fertilize eggs directly impacts their fitness, but the secondary sexual traits that often guide mate choice may not be directly correlated with male fertility. In externally fertilizing species, such as many fish species, chemical cues in ejaculates may allow females to assess male fertilization capacity. However, chemical cues associated with sperm release have only been described in a few species, and evidence that females use these cues to discriminate among males remains limited. Female sea lamprey, Petromyzon marinus , use several chemical cues to find and interact with potential mates, including a sex pheromone released by males across their gill epithelia and a second sex pheromone released in their semen. Unlike males of many fish species that control pheromone release via urinary pulses, male sea lamprey continually broadcast the gill pheromone once they are sexually mature. This presents a potentially costly scenario for females because attraction to males that are not actively spawning or that are sperm-depleted likely wastes time and energy. We tested the hypothesis that female sea lamprey use pheromones present in seminal plasma to discriminate among potential mates. In-stream behavioural assays revealed that females (1) preferred seminal plasma + male-conditioned water (containing gill-released pheromones) over male-conditioned water alone, (2) preferred male-conditioned water + 2× seminal plasma over male-conditioned water + 1× seminal plasma and (3) oriented towards seminal plasma over large distances and when no male-conditioned water was applied. Taken together, our results indicate that female sea lamprey use seminal pheromones to find and remain near males with immediate fertilization capacity, thereby reducing the risk of wasting time and energy during their single, reproductive window. Finally, our study highlights the importance of multiple cues in mate choice. • We tested whether seminal pheromones provide cues to female lamprey about male status. • Females discriminated males based on the presence of seminal pheromones. • Females discriminated males based on the concentration of seminal pheromones. • Seminal pheromones are a potent, independent cue in sea lamprey. [ABSTRACT FROM AUTHOR]

AbstractThe fall armyworm (FAW) is a significant pest of maize worldwide. Here, we evaluated the feasibility of mating disruption (MD) of FAW and the MD mechanisms involved using hand-applied pheromone dispensers with intermediate release rate and point density in maize plots. To understand the mechanisms underlying the MD of FAW, male captures and device density data were compared using profile analysis. In the first trial, we tested 0, 10, 30, and 40 dispensers/ha, and then 0, 20, 40, and 60 dispensers/ha in the second trial. Male captures were reduced up to 87% in MD plots. In the first trial, the percentage of plants damaged by larvae was lower in plots with 30 and 40 dispensers/ha, whereas in the second trial, the lower percentage of damaged plants was observed in plots treated with 60 pheromone dispensers/ha. There was no difference in maize yield between the MD-treated and control treatments. The profile analysis matched the predictions of hybrid MD mediated by a combination of non-competitive and competitive mechanisms. Although our results showed that sexual communication in FAW adults may be disrupted to a certain extent, further studies are needed to corroborate the potential of MD for FAW management. [ABSTRACT FROM AUTHOR]

The invasion of fall armyworm (FAW) to the Eastern hemisphere poses a major challenge to the food security efforts of several nations including India. Invasive FAW population is primarily composed of two predominant strains differentiated based on the mitochondrial cytochrome c oxidase (COI) gene, known as COI-RS (hybrid strain) and COI-CS (corn strain). COI-RS, in particular was found to be different from the ancestral rice strain in America and displayed characteristics of typical inter-strain hybrid population. Although the ancestral populations have been tested for their mating behaviour and response toward pheromones and biocontrol agents, similar studies have not been performed on the invasive populations. We report here the interstrain mating behaviour of COI-RS and COI-CS populations from India along with their susceptibilities towards different biocontrol agents. COI-RS larvae were more susceptible to SpfrNPV infection compared to COI-CS larvae. The response towards other biocontrol agents was similar in the two strains. Electroantennogram response study revealed that the two strains differed in their response towards FAW pheromone, where COICS males displayed higher mean antennal response towards Z-9-tetradecenyl acetate (87%), Z-11-hexadecenyl acetate (12.5%) and Z-7-dodecenyl acetate (0.5%) than COI-RS males. Similar to the ancestral population, we found unidirectional mating between COI-RS females and COI-CS males while the reverse cross did not yield viable offspring. However, further detailed studies are required to confirm this observation. [ABSTRACT FROM AUTHOR]

Studies of oriental fruit moth (OFM), Grapholita molesta (Busck), and codling moth (CM), Cydia pomonella (L.) (Lepidoptera: Tortricidae), both important pests of pome fruit, evaluated the addition of low‐intensity light‐emitting diode (LED) to delta traps baited with 3 commercial monitoring lures. Studies were conducted in 9 orchards treated with and without sex pheromone mating disruption for one or both species. OFM was monitored with a two‐part pheromone/kairomone lure (OFM Combo Dual), while CM was monitored with either a two‐part kairomone lure (CM Dual 4 K) or a sex pheromone lure (CM PH). Both pests were monitored with or without the addition of three types of a low power LED light with peak intensity at 395 (UV‐A), 458 (blue), and 516 (green) nm. The UV‐A LED was found to be the most effective among the three lights for OFM. Unexpectedly, traps with the OFM Combo Dual lure plus UV‐A LED caught similar numbers of CM as traps baited with the CM Dual 4 K and CM PH lures alone. They also caught other pest species, such as oblique banded leafroller (OBLR), Choristoneura rosaceana (Harris), and peach twig borer (PTB), Anarsia lineatella (Zeller). Interestingly, in different trials the OFM Combo Dual combined with UV‐A LED light caught significantly more OFM and/or CM females compared to the OFM Combo Dual lure without light, opening the perspective for a female‐oriented monitoring and for a “female removal” management approach of these pests. The development of inexpensive, dual‐modality traps adding a light stimulus to a pheromone/kairomone lure may reduce monitoring costs in orchards with multiple moth pests, improving the trapping efficiency. [ABSTRACT FROM AUTHOR]

Many animals exchange chemicals during courtship and mating. In some amphibians, sexual chemical communication is mediated by pheromones produced in male breeding glands that are transferred to the female's nostrils during mating. This has been mostly studied in salamanders, despite frogs having similar glands and courtship behaviours suggestive of chemical communication. In Neotropical poison frogs (Dendrobatidae and Aromobatidae), males of many species develop breeding glands in their fingers, causing certain fingers to visibly swell. Many also engage in cephalic amplexus, whereby the male's swollen fingers are placed in close contact with the female's nares during courtship. Here, we investigate the possible roles of swollen fingers in pheromone production using whole‐transcriptome sequencing (RNAseq). We examined differential gene expression in the swollen versus non‐swollen fingers and toes of two dendrobatid species, Leucostethus brachistriatus and Epipedobates anthonyi, both of which have specialised mucous glands in finger IV, the latter of which has cephalic amplexus. The overwhelming pattern of gene expression in both species was strong upregulation of sodefrin precursor‐like factors (SPFs) in swollen fingers, a well‐known pheromone system in salamanders. The differentially expressed SPF transcripts in each species were very high (>40), suggesting a high abundance of putative protein pheromones in both species. Overall, the high expression of SPFs in the swollen fingers in both species, combined with cephalic amplexus, supports the hypothesis that these traits, widespread across members of the subfamilies Colostethinae and Hyloxalinae (ca. 141 species), are involved in chemical signalling during courtship. [ABSTRACT FROM AUTHOR]

The tea tussock moth is a pest that damages tea leaves, affecting the quality and yield of tea and causing huge economic losses. The efficient asymmetric total synthesis of the sex pheromone of the tea tussock moth was achieved using commercially available starting materials with a 25% overall yield in 11 steps. Moreover, the chiral moiety was introduced by Evans' template and the key C-C bond construction was accomplished through Julia–Kocienski olefination coupling. The synthetic sex pheromone of the tea tussock moth will facilitate the subsequent assessment and implementation of pheromones as environmentally friendly tools for pest management. [ABSTRACT FROM AUTHOR]

Bee alarm pheromones are essential molecules that are present in beehives when some threats occur in the bee population. In this work, we have applied multilevel modeling techniques to understand molecular interactions between representative bee alarm pheromones and polymers such as polymethyl siloxane (PDMS), polyethylene glycol (PEG), and their blend. This study aimed to check how these interactions can be manipulated to enable efficient separation of bee alarm pheromones in portable membrane inlet mass spectrometric (MIMS) systems using new membranes. The study involved the application of powerful computational atomistic methods based on a combination of modern semiempirical (GFN2-xTB), first principles (DFT), and force-field calculations. As a fundamental work material for the separation of molecules, we considered the PDMS polymer, a well-known sorbent material known to be applicable for light polar molecules. To improve its applicability as a sorbent material for heavier polar molecules, we considered two main factors—temperature and the addition of PEG polymer. Additional insights into molecular interactions were obtained by studying intrinsic reactive properties and noncovalent interactions between bee alarm pheromones and PDMS and PEG polymer chains. [ABSTRACT FROM AUTHOR]

Sesquiterpenoids constitute the largest subgroup of terpenoids that have numerous applications in pharmaceutical, flavor, and fragrance industries as well as biofuels. Bergamotenes, a type of bicyclic sesquiterpenes, are found in plants, insects, and fungi with α-trans-bergamotene as the most abundant compound. Bergamotenes and their related structures (Bergamotane sesquiterpenoids) have been shown to possess diverse biological activities such as antioxidant, anti-inflammatory, immunosuppressive, cytotoxic, antimicrobial, antidiabetic, and insecticidal effects. However, studies on their biotechnological potential are still limited. This review compiles the characteristics of bergamotenes and their related structures in terms of occurrence, biosynthesis pathways, and biological activities. It further discusses their functionalities and potential applications in pharmaceutical, nutraceuticals, cosmeceuticals, and pest management sectors. This review also opens novel perspectives in identifying and harnessing bergamotenes for pharmaceutical and agricultural purposes. [ABSTRACT FROM AUTHOR]

Bacterial interactions are vital for adapting to changing environments, with quorum sensing (QS) systems playing a central role in coordinating behaviors through small signaling molecules. The RRNPPA family is the prevalent QS systems in Bacillota and mediating communication through secreted oligopeptides, which are processed into active pheromones by extracellular proteases. Notably, in several cases the propeptides show the presence of multiple putative pheromones within their sequences, which has been proposed as a mechanism to diversify peptide-receptor specificity and potentially facilitate new functions. However, neither the processes governing the maturation of propeptides containing multiple pheromones, nor their functional significance has been evaluated. Here, using 2 Rap systems from bacteriophages infecting Bacillus subtilis that exhibit different types of pheromone duplication in their propeptides, we investigate the maturation process and the molecular and functional activities of the produced pheromones. Our results reveal that distinct maturation processes generate multiple mature pheromones, which bind to receptors with varying affinities but produce identical structural and biological responses. These findings add additional layers in the complexity of QS communication and regulation, opening new possibilities for microbial social behaviors, highlighting the intricate nature of bacterial interactions and adaptation. Some bacterial quorum sensing (QS) systems use oligopeptide pheromones to orchestrate adaptive responses to the environment. This study shows that extracellular proteases yield multiple pheromones from tandemly duplicated propeptides, adding complexity to QS responses. [ABSTRACT FROM AUTHOR]

The ability to recognize and differentiate between conspecifics and heterospecifics as well as their signals is critical for the coexistence of closely related species. In the genus Rattus , species are morphologically similar and multiple species often coexist. Here, we investigated the interspecific recognition and signal differentiation of two sympatric rat species, the brown rat (Rattus norvegicus , RN) and the Asian house rat (Rattus tanezumi , RT). In a two-way choice test, both RN and RT females showed a preference for conspecific male rats to heterospecific ones. RT females showed a significant preference for accessible urine of males of same species to those of other species, but not for the inaccessible urine. On the other hand, there were significant differences in the structural characteristics of the ultrasonic vocalization emitted by males of these two rat species. Sodium dodecyl sulphate‒polyacrylamide gel electrophoresis (SDS‒PAGE) and isoelectric focusing electrophoresis unveiled that major urinary proteins (MUPs) in voided urine were more highly expressed in RN males versus RT males. The interspecific differences of urinary volatile compounds were also discussed. In conclusion, female rats had the ability to distinguish between males of either species. [ABSTRACT FROM AUTHOR]

Sex pheromones are considered to play critical roles in partner communication of most parasitic Hymenoptera. However, the identification of sex pheromone components remains limited to a few families of parasitoid wasps. In this study, we functionally characterized a candidate sex pheromone component in Microplitis mediator (Hymenoptera: Braconidae), a solitary parasitoid of Noctuidae insects. We found that the body surface extract from female wasps could significantly stimulate courtship behavior of males. Gas chromatography‐electroantennographic detection (GC‐EAD) analysis revealed that a candidate semiochemical from extract triggered significant electrophysiological response of antennae of males. By performing gas chromatography‐mass spectrometer (GC‐MS) measurement, GC‐EAD active compound was identified as n‐octyl acrylate, a candidate sex pheromone component in female M. mediator. In electroantennogram (EAG) tests, antennae of male wasps showed significantly higher electrophysiological responses to n‐octyl acrylate than those of females. Y‐tube olfactometer assays indicated that male wasps significantly chose n‐octyl acrylate compared with the control. Furthermore, male wasps showed a remarkable preference for n‐octyl acrylate in a simulated field condition behavioral trial; simultaneously, n‐octyl acrylate standard could also trigger significant courtship behavior in males. We propose that n‐octyl acrylate, as a candidate vital sex pheromone component, could be utilized to design behavioral regulators of M. mediator to implement the protection and utilization of natural enemies. [ABSTRACT FROM AUTHOR]

In this article, the multi-objective Travelling Salesman Problem (TSP), which includes the optimization of two competing and incompatible goals, is taken into account. There is not a single ideal strategy that enhances all the objective functions at once. Usually, one of the goals is considered a constraint or both goals are combined into one objective function. This work provides an extremely efficient Ant Colony Optimization (ACO)-based multi-objective Fruit Fly Optimization Algorithm (FFOA). Using FFOA, which was normalized and initialized to the pheromone quantity for ACO, the present study first establishes a local solution. To evaluate the optimization results a combined method of FFOA and ACO is carried out. [ABSTRACT FROM AUTHOR]

Vasoactive-intestinal peptide (Vip) is a pleiotropic peptide with a wide range of distribution and functions. Zebrafish possess 2 isoforms of Vip (a and b), in which Vipa is most homologous to the mammalian form. In female zebrafish, Vipa can stimulate LH secretion from the pituitary but is not essential for female reproduction, as vipa −/− females display normal reproduction. In contrast, we have found that vipa −/− males are severely subfertile and sex ratio of offspring is female-biased. By analyzing all aspects of male reproduction with wild-type (WT) males, we show that the testes of vipa −/− are underdeveloped and contain ∼70% less spermatids compared to WT counterparts. The sperm of vipa −/− males displayed reduced potency in terms of fertilization (by ∼80%) and motility span and duration (by ∼50%). In addition, vipa −/− male attraction to WT females was largely nonexistent, indicating decreased sexual motivation. We show that vipa mRNA and protein is present in Leydig cells and in developing germ cells in the testis of WT, raising the possibility that endogenous Vipa contributes to testicular function. Absence of Vipa in vipa −/− males resulted in downregulation of 3 key genes in the androgen synthesis chain in the testis, 3β-hsd, 17β-hsd1 , and cyp11c1 (11β-hydrogenase), associated with a pronounced decrease in 11-ketotestosterone production and, in turn, compromised reproductive fitness. Altogether, this study establishes a crucial role for Vipa in the regulation of male reproduction in zebrafish, like in mammals, with the exception that Vipa is also expressed in zebrafish testis. [ABSTRACT FROM AUTHOR]

The paper proposes a genetic ant colony algorithm that integrates genetic and ant colony algorithms, enhancing the heuristic function of the latter, to address target point distribution issues in large well clusters. This algorithm utilizes genetic algorithms for initial pheromone distribution and employs the ant colony algorithm to achieve rapid convergence. Introducing genetic operators in each iteration addresses the ant colony system's drawbacks, including scarcity of initial pheromones, susceptibility to local optima, and slow convergence speed. The model aims to minimize the sum of horizontal displacement and intersections in line connections from wellheads to target points as its dual-objective function. It validates the effectiveness of the genetic ACO algorithm in optimizing target point allocation at wellheads through a case study, highlighting its advantages over traditional methods in reducing displacement, ensuring result stability, and preventing collisions. [ABSTRACT FROM AUTHOR]

The European spruce bark beetle, Ips typographus (L.), is the most important forest pest in Europe due to the profound impacts of periodic outbreaks on ecosystem goods and services. Herein, we evaluated the responses of I. typographus to different doses of verbenone (SPLAT® Verb, 10% (−)‐verbenone by weight; ISCA Inc., Riverside, CA, USA) in traps baited with its aggregation pheromones. Results are based on 1,492,289 I. typographus collected in five experiments over 3 years. SPLAT® Verb inhibited the response of I. typographus to baited traps out to 14 m from the point of release (dollop) and for >80 days at a dose of 75 g per dollop. Reductions in trap catch ranged from 34% to 93% depending on the dose of verbenone, age of SPLAT® Verb dollops, distance from dollops and the environment. In forest stands, significant reductions in trap catch were observed at distances up to 14 m from the point of release, with the largest reductions observed at 0 m (93%) and 2 m (64%). In an open area, significant reductions in trap catch were observed at distances up to only 2 m from the point of release, with the largest reduction observed at 0 m (66%). The much lower active inhibitory range of verbenone in the open area appears to be explained by less stable accumulations of verbenone in the surrounding air. There was a significant negative correlation between trap catch and the amount of verbenone measured in air in the vicinity of traps. We also observed inhibition of the sixtoothed spruce bark beetle, Pityogenes chalcographus (L.), another important forest pest in Europe, at all doses (20, 40, 75 and 100 g) of SPLAT® Verb that were evaluated. The implications of these and other results to the management of I. typographus are discussed. [ABSTRACT FROM AUTHOR]

Introduction: Bacterial resistance presents a major challenge to both the ecological environment and human well-being, with persistence playing a key role. Multiple studies were recently undertaken to examine the factors influencing the formation of persisters and the underlying process, with a primary focus on Gram-negative bacteria and Staphylococcus aureus (Gram-positive bacteria). Enterococcus faecalis (E. faecalis) is capable of causing a variety of infectious diseases, but there have been few studies of E. faecalis persisters. Previous studies have shown that the sex pheromone cCF10 secreted by E. faecalis induces conjugative plasmid transfer. However, whether the pheromone cCF10 regulates the persistence of E. faecalis has not been investigated. Methods: As a result, we investigated the effect and potential molecular mechanism of pheromone cCF10 in regulating the formation of persisters in E. faecalis OG1RF using a persistent bacteria model. Results and discussion: The metabolically active E. faecalis OG1RF reached a persistence state and temporarily tolerated lethal antibiotic concentrations after 8  h of levofloxacin hydrochloride (20  mg/mL) exposure, exhibiting a persistence rate of 0.109 %. During the growth of E. faecalis OG1RF, biofilm formation was a critical factor contributing to antibiotic persistence, whereas 10  ng/mL cCF10 blocked persister cell formation. Notably, cCF10 mediated the antibiotic persistence of E. faecalis OG1RF via regulating metabolic activity rather than suppressing biofilm formation. The addition of cCF10 stimulated the Opp system and entered bacterial cells, inhibiting (p)ppGpp accumulation, thus maintaining the metabolically active state of bacteria and reducing persister cell generation. These findings offer valuable insights into the formation, as well as the control mechanism of E. faecalis persisters. [ABSTRACT FROM AUTHOR]

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier), also known as the Asian palm weevil, is an invasive pest that causes widespread damage to palm trees around the globe. As pheromone communication is crucial for their mass attack and survival on palm trees, the olfactory concept of pest control strategies has been widely explored recently. We aim to understand the molecular basis of olfaction in RPW by studying one of the key olfactory proteins in insect pheromone communication, sensory neuron membrane proteins (SNMPs). SNMPs belong to the CD36 (cluster of differentiation 36) family that perform two distinct olfactory roles in insects, either in pheromone (odorant) transfer to the odorant receptors (SNMP1) or in the pheromone clearing process (SNMP2). In this study, we performed antennal transcriptomic screening and identified six SNMPs, mapping them on the R. ferrugineus genome, and confirmed four distinct SNMPs. Both SNMP1 proteins in RPW, viz., RferSNMPu1 and RferSNMPu2, were mapped onto the same scaffold in different loci in the RPW genome. To further understand the function of these proteins, we first classified them using phylogenetic analysis and checked their tissue-specific expression patterns. Further, we measured the relative transcript abundance of SNMPs in laboratory-reared, field-collected adults and pheromone-exposure experiments, ultimately identifying RferSNMPu1 as a potential candidate for functional analysis. We mapped RferSNMPu1 expression in the antennae and found that expression patterns were similar in both sexes. We used RNAi-based gene silencing to knockdown RferSNMPu1 and tested the changes in the RPW responses to aggregation pheromone compounds, 4-methyl-5-nonanol (ferrugineol) and 4-methyl-5-nonanone (ferrugineone), and a kairomone, ethyl acetate using electroantennogram (EAG) recordings. We found a significant reduction in the EAG recordings in the RferSNMPu1 knockdown strain of adult RPWs, confirming its potential role in pheromone detection. The structural modelling revealed the key domains in the RferSNMPu1 structure, which could likely be involved in pheromone detection based on the identified ectodomain tunnels. Our studies on RferSNMPu1 with a putative role in pheromone detection provide valuable insight into understanding the olfaction in R. ferrugineus as well as in other Curculionids, as SNMPs are under-explored in terms of its functional role in insect olfaction. Most importantly, RferSNMPu1 can be used as a potential target for the olfactory communication disruption in the R. ferrugineus control strategies. [ABSTRACT FROM AUTHOR]

Environment in general and social signals in particular could alter development. In Caenorhabditis elegans, male pheromones hasten development of hermaphrodite larvae. We show that this involves acceleration of growth and both somatic and germline development during the last larval stage (L4). Larvae exposed to male pheromones spend more time in L3 and less in the quiescent period between L3 and L4. This behavioral alteration improves provision in early L4, likely allowing for faster development. Larvae must be exposed to male pheromones in late L3 for behavioral and developmental effects to occur. Latter portions of other larval stages also contain periods of heightened sensitivity to environmental signals. Behavior during the early part of the larval stages is biased toward exploration, whereas later the emphasis shifts to food consumption. We argue that this organization allows assessment of the environment to identify the most suitable patch of resources, followed by acquisition of sufficient nutrition and salient information for the developmental events in the next larval stage. Evidence from other species indicates that such coordination of behavior and development may be a general feature of larval development. [ABSTRACT FROM AUTHOR]

This document provides detailed information on the synthesis and characterization of various compounds, including (E)-1,1-Diethoxyhexadec-11-en-9-yne, (E)-1,1-Diethoxytetradec-8-en-10-yne, (E)-1,1-Diethoxypentadec-9-en-11-yne, 9-tert-Butoxynon-1-yne, and (E)-9-tert-Butoxy-1-iodonon-1-ene. The data presented can be used by researchers studying these compounds for various applications. The document includes information on the reaction conditions, yields, and spectroscopic data for each compound, and the procedures involve specific reagents and catalysts to reduce triple bonds in the compounds. The resulting products are then purified and extracted using various techniques. [Extracted from the article]

This article focuses on the emergence of cooperation in societies of self-interested agents. In particular, it introduces a mechanism based on indirect—stigmergic—interactions between agents moving in an environment, to express the likeliness of finding cooperative partners. On the one hand, agents that find themselves cooperating with others emit pheromones in their current location, expressing the presence of agents willing to cooperate. On the other hand, agents that sense pheromones tend to move towards regions with a higher pheromone concentration. Results show that this mechanism leads to the emergence of spatial regions where cooperation can be effectively sustained, and in which agents can overall get better payoffs than those agents not taking into account pheromones in their choices. [ABSTRACT FROM AUTHOR]

Background: Accurate detection of pheromones is crucial for chemical communication and reproduction in insects. In holometabolous flies and moths, the sensory neuron membrane protein 1 (SNMP1) is essential for detecting long-chain aliphatic pheromones by olfactory neurons. However, its function in hemimetabolous insects and its role for detecting pheromones of a different chemical nature remain elusive. Therefore, we investigated the relevance of SNMP1 for pheromone detection in a hemimetabolous insect pest of considerable economic importance, the desert locust Schistocerca gregaria, which moreover employs the aromatic pheromone phenylacetonitrile (PAN) to govern reproductive behaviors. Results: Employing CRISPR/Cas-mediated gene editing, a mutant locust line lacking functional SNMP1 was established. In electroantennography experiments and single sensillum recordings, we found significantly decreased electrical responses to PAN in SNMP1-deficient (SNMP1−/−) locusts. Moreover, calcium imaging in the antennal lobe of the brain revealed a substantially reduced activation of projection neurons in SNMP1−/− individuals upon exposure to PAN, indicating that the diminished antennal responsiveness to PAN in mutants affects pheromone-evoked neuronal activity in the brain. Furthermore, in behavioral experiments, PAN-induced effects on pairing and mate choice were altered in SNMP1−/− locusts. Conclusions: Our findings emphasize the importance of SNMP1 for chemical communication in a hemimetabolous insect pest. Moreover, they show that SNMP1 plays a crucial role in pheromone detection that goes beyond long-chain aliphatic substances and includes aromatic compounds controlling reproductive behaviors. [ABSTRACT FROM AUTHOR]

Teratorhabditis palmarum Gerber and Giblin-Davis, 1990, a free-living nematode, is able to produce hundreds of thousands of offspring in a short time. Reproduction is the main feature that defines life and, therefore, it plays an important role in determining what kinds of selective parameters play a powerful role in the maturity and evolution of mating systems. In the present study, we estimated the features of mating behaviour of Teratorhabditis using long-time microscopic videography and repeated observations. The mating behaviour of Teratorhabditis could be separated into a series of successive behaviours, including pre-mating (searching and contacting), mating (copulating) and post-mating (enduring). Here, we present the mating behaviour of 2- and 10-day-old virgin males and females. The mean time of the four phases – searching, contacting, copulating and enduring – varied significantly, at 24.6 ± 4.6 min, 36 ± 5.7 min, 31 ± 4.1 min and 10 ± 2.3 min in 2-day-old and 38.2 ± 3.3 min, 44.3 ± 5.0 min, 39 ± 4.3 min and 11 ± 3.2 min in 10-day-old individuals, respectively. Attraction between the sexes was observed, indicating the probable involvement of sex pheromone(s) in mating behaviour. In all age groups of males there was a significant increase in the duration of mating as the females aged. As the mobility of ageing individuals was reduced, this may have directly influenced the durations of the various phases of mating behaviour. [ABSTRACT FROM AUTHOR]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), is a highly destructive invasive pest targeting Solanaceae crops. Its olfactory system plays a crucial role in host location, mate finding, and other behavioral activities. However, there is a notable gap in the literature regarding the characterization of its chemosensory genes. In this study, we conducted a genome-wide identification of 58 odorant receptors (ORs) of T. absoluta. The identified ORs exhibit coding sequence (CDS) lengths ranging from 1062 bp to 1419 bp, encoding proteins of 354 to 473 amino acids. Gene structure analysis showed that the majority of these ORs consist of five, seven, eight, or nine exons, collectively representing 67% of the total ORs identified. Through chromosomal mapping, we identified several tandemly duplicate genes, including TabsOR12a, TabsOR12b, TabsOR12c, TabsOR21a, TabsOR21b, TabsOR34a, TabsOR34b, TabsOR34c, TabsOR62a, and TabsOR62b. The phylogenetic analysis indicated that six TabsORs were clustered within the lepidopteran sex pheromone receptor clade, while an expansion clade containing ten TabsORs resulted from tandem duplication events. Additionally, five TabsORs were classified into a specific OR clade in T. absoluta. Furthermore, through RNA-Seq and RT-qPCR analyses, we identified five TabsORs (TabsOR21a, TabsOR26a, TabsOR34a, TabsOR34c, and TabsOR36) exhibiting female-antennae-biased expression. Our study provides a valuable foundation to further investigations into the molecular and ecological functions of TabsORs, particularly in relation to oviposition behavior. These findings provide foundational data for the future exploration of the functions of female-biased expression OR genes in T. absoluta, thereby facilitating the further development of eco-friendly attract-and-kill techniques for the prevention and control of T. absoluta. [ABSTRACT FROM AUTHOR]

Ant physiology has been fashioned by 100 million years of social evolution. Ants perform many sophisticated social and collective behaviors yet possess nervous systems similar in schematic and scale to that of the fruit fly Drosophila melanogaster, a popular solitary model organism. Ants are thus attractive complementary subjects to investigate adaptations pertaining to complex social behaviors that are absent in flies. Despite research interest in ant behavior and the neurobiological foundations of sociality more broadly, our understanding of the ant nervous system is incomplete. Recent technical advances have enabled cutting-edge investigations of the nervous system in a fashion that is less dependent on model choice, opening the door for mechanistic social insect neuroscience. In this review, we revisit important aspects of what is known about the ant nervous system and behavior, and we look forward to how functional circuit neuroscience in ants will help us understand what distinguishes solitary animals from highly social ones. [ABSTRACT FROM AUTHOR]

Pheromones and olfactory communication play vital roles in sex recognition and mate choice in rodents. Asian house rats (Rattus tanezumi) (RT) often startle easily, making behavioral measurements difficult to carry out accurately in the laboratory. Here, the behavioral and olfactory preferences of the female RT between males and females were not observed using a conventional two‐choice device; we then explored the neuro‐immunohistochemical evidence in the brains of RT females. We found that male urine elicited significantly higher c‐fos expression in the accessory olfactory system and sex‐related brain regions in females than female urine did. On the other hand, the differences of volatile compounds and major urinary proteins (MUPs) in both voided urine and preputial glands (PGs) of the RT were detected using gas chromatography–mass spectrometer, sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, isoelectric focusing electrophoresis, and liquid chromatography–electrospray ionization mass spectrometry. We found that PG‐derived 1‐(4,5‐dihydro‐2‐thiazolyl)‐ethanone and total MUPs were more abundant in males versus females, suggesting these sexually divergent components might activate the female's accessory olfactory system. In conclusion, the neuro‐immunohistochemical evidence indicated that potential sex pheromones might exist in RT; however, the strength of the chemical signal might be too weak to cause behavioral responses in females. [ABSTRACT FROM AUTHOR]

Wolves, akin to their fellow canids, extensively employ chemical signals for various aspects of communication, including territory maintenance, reproductive synchronisation and social hierarchy signalling. Pheromone‐mediated chemical communication operates unconsciously among individuals, serving as an innate sensory modality that regulates both their physiology and behaviour. Despite its crucial role in the life of the wolf, there is a lacuna in comprehensive research on the neuroanatomical and physiological underpinnings of chemical communication within this species. This study investigates the vomeronasal system (VNS) of the Iberian wolf, simultaneously probing potential alterations brought about by dog domestication. Our findings demonstrate the presence of a fully functional VNS, vital for pheromone‐mediated communication, in the Iberian wolf. While macroscopic similarities between the VNS of the wolf and the domestic dog are discernible, notable microscopic differences emerge. These distinctions include the presence of neuronal clusters associated with the sensory epithelium of the vomeronasal organ (VNO) and a heightened degree of differentiation of the accessory olfactory bulb (AOB). Immunohistochemical analyses reveal the expression of the two primary families of vomeronasal receptors (V1R and V2R) within the VNO. However, only the V1R family is expressed in the AOB. These findings not only yield profound insights into the VNS of the wolf but also hint at how domestication might have altered neural configurations that underpin species‐specific behaviours. This understanding holds implications for the development of innovative strategies, such as the application of semiochemicals for wolf population management, aligning with contemporary conservation goals. [ABSTRACT FROM AUTHOR]

Lobesia botrana (Lepidoptera: Tortricidae) and Cryptoblabes gnidiella (Lepidoptera: Pyralidae) represent a threat to wine production in Mediterranean countries. In recent years, the development of new formulations promoted the spread of pheromone-based mating disruption (MD) as an effective tool for the management of several insect pests in different agricultural contexts. In this study, we investigated the efficacy of an experimental dispenser designed for simultaneous MD of these two pests. The biodegradable double-tube dispenser (Isonet® L CG-BIOX235) was tested for two years in two Italian wine-growing sites, the first in Apulia (Southern Italy), and the second in Tuscany (Central Italy). Isonet® L CG-BIOX235 efficacy was evaluated by testing different doses (i.e., 300, 400, and 500 dispensers/ha), on different varieties (i.e., Aglianico, Syrah, and Viognier), and comparing it with an untreated control. The MD performed using this dispenser significantly reduced the infestation of both L. botrana (i.e., percentage of infested bunches and number of nests per bunch) and C. gnidiella compared to the untreated control, although the occurrence of the latter fluctuated throughout the two-year trials. Overall, although our results underline the possibility of combining the pheromones of the two pests in a single dispenser for their simultaneous MD, they also highlight the need for further studies on some aspects of C. gnidiella biology and consequently improve the MD efficacy against this species. [ABSTRACT FROM AUTHOR]

The Lichen moth, Lyclene dharma dharma (Arctiidae, Lithosiinae), plays a significant role in forest ecosystem dynamics. A concise and novel method to synthesize the active sex pheromone components, (S)-14-methyloctadecan-2-one ((S)-1), (S)-6-methyloctadecan-2-one ((S)-2), and their enantiomers has been developed. Key steps in the synthesis include the use of Evans' chiral auxiliaries, Grignard cross-coupling reactions, hydroboration–oxidation, and Wacker oxidation. The synthesized sex pheromone components hold potential value for studies on communication mechanisms, species identification, and ecological management. [ABSTRACT FROM AUTHOR]

Sex pheromones play crucial role in mating behavior of moths, involving intricate recognition mechanisms. While insect chemical biology has extensively studied type I pheromones, type II pheromones remain largely unexplored. This study focused on Helicoverpa armigera, a representative species of noctuid moth, aiming to reassess its sex pheromone composition. Our research unveiled two previously unidentified candidate type II sex pheromones—3Z,6Z,9Z-21:H and 3Z,6Z,9Z-23:H—in H. armigera. Furthermore, we identified HarmOR11 as an orphan pheromone receptor of 3Z,6Z,9Z-21:H. Through AlphaFold2 structural prediction, molecular docking, and molecular dynamics simulations, we elucidated the structural basis and key residues governing the sensory nuances of both type I and type II pheromone receptors, particularly HarmOR11 and HarmOR13. This study not only reveals the presence and recognition of candidate type II pheromones in a noctuid moth, but also establishes a comprehensive structural framework for PRs, contributing to the understanding of connections between evolutionary adaptations and the emergence of new pheromone types. [ABSTRACT FROM AUTHOR]

The aboveground oligolectic bee, Heriades truncorum, is a particularly good model for studying the impact of pesticides on sexual communication, since some aspects of its mating behavior have previously been described. We have tested (1) the interference of the pesticide flupyradifurone on male precopulatory behavior and male mating partner preferences, (2) the way that the pesticide interferes in male quality assessment by the female, and (3) the effects of the pesticide on the chemical compounds in the female cuticle. We exposed bees of both sexes to a sublethal concentration of flupyradifurone. Various behaviors were registered in a mating arena with two females (one unexposed and one exposed) and one male (either unexposed or exposed). Unexposed males were quicker to attempt to mate. Treatment also impacted precopulatory behavior and male quality assessment by females. Males approached unexposed females more quickly than insecticide‐exposed ones. Females exposed to insecticide produced lower amounts of some cuticular hydrocarbons (sex pheromone candidates) and appeared less choosy than unexposed females. Our findings suggest that insecticide exposure affects sexual communication, playing a role both in male preference and in male quality assessment by the female. [ABSTRACT FROM AUTHOR]

In many amphibians, males have sexually dimorphic breeding glands, which can produce proteinaceous or volatile pheromones, used for intraspecific communication. In this study we analyse two types of glands in the Mexican treefrog Ptychohyla macrotympanum (Hylidae)—large ventrolateral glands and small nuptial pads on their fingers—using histology, whole-transcriptome sequencing, and phylogenetic analyses. We found strong differences in glandular tissue composition and gene expression patterns between the two breeding gland types. In both glands we only found low expression of protein pheromone candidates. Instead, in the ventrolateral glands, gene expression was strikingly dominated by nicotinamide N -methyltransferase (NNMT)-like genes. The diversity of these genes was remarkably high, with at least 68 distinct NNMT-like genes. Our comparative phylogenetic analysis of the diversity of NNMT-like genes across vertebrates indicates that the extreme diversity of this gene is largely a frog-specific phenomenon and can be traced to large numbers of relatively recent gene duplications occurring independently in many lineages. The strong dominance and astonishing diversity of NNMT-like genes found in anurans in general, and in their sexually dimorphic breeding glands specifically, suggests an important function of NNMT-like proteins for anuran reproduction, possibly being related to volatile pheromone production. [ABSTRACT FROM AUTHOR]

Scyphophorus acupunctatus Gyllenhal is a major pest of agaves in Mexico. This weevil oviposits on the buds of agave plants; upon larval emergence, feeds by burrowing and forming galleries inside the plants, causing damage to the tissues and making them susceptible to phytopathogens. The cryptic life of S. acupunctatus complicates its control with insecticides; therefore, other pest management tools, such as insect behavioral manipulation, are worth investigating. The host- and mate-finding behaviors of S. acupunctatus are mediated by an aggregation pheromone and host volatiles. Monitoring and mass trapping with infochemicals may be effective management strategy. But host volatiles must be evaluated and optimized before implementation as management tools. The synergism of fresh (unfermented) agave leaf pieces or stalks, fermented with molasses, and unfermented pineapple husks were evaluated as substitutes for agave in the capture of S. acupunctatus. Fermented pieces of agave stalk were evaluated using pheromone-baited traps, and their effects of the two trap designs and two pheromone dispensers. Our results showed that pheromone-baited traps significantly increased the capture of S. acupunctatus when used with fermented agave stalk with molasses or unfermented pineapple peels. The type of pheromone dispenser did not influence the capture of S. acupunctatus. We describe an efficient system to attract and capture agave weevils as a promising tool for monitoring and mass trapping this pest. Resumen Scyphophorus acupunctatus Gyllenhal es una plaga importante del agave en México. Este picudo oviposita en los cogollos de las plantas de agave. Al emerger las larvas se alimentan de éstas, barrenan y forman galerías hacia el interior de las plantas, lo que causa daño a los tejidos y los vuelve susceptibles a fitopatógenos. La vida críptica de S. acupunctatus complica su control con insecticidas, por lo que vale la pena investigar otras herramientas de manejo de plagas, como la manipulación de su comportamiento. El comportamiento de busqueda de huesped y pareja de S. acupunctatus están mediados por una feromona de agregación y volátiles del huésped. Por lo tanto, monitorearlos y atraparlos masivamente con infoquímicos pueden ser buenas estrategias de manejo. Los volátiles del hospedero deben evaluarse y optimizarse antes de implementarse como herramientas de control. Se evaluó el sinergismo de trozos de hojas o pencas de agave frescas (sin fermentar), fermentadas con melaza, y cáscara de piña sin fermentar como sustitutos del agave en la captura de S. acupunctatus. Los trozos de pencas de agave fermentadas se evaluaron utilizando trampas cebadas con feromonas. También probamos los efectos de dos diseños de trampas y dos dispensadores de feromonas. Nuestros resultados mostraron que las trampas cebadas con feromonas aumentaron significativamente la captura de S. acupunctatus cuando se usaron con trozos de pencas de agave fermentado con melaza o cáscara de piña sin fermentar. Los tipos de dispensadores de feromonas evaluados no influyeron en las capturas de S. acupunctatus. Describimos un sistema eficiente para atraer y capturar al picudo del agave como una herramienta prometedora para el monitoreo y captura masiva de esta plaga. [ABSTRACT FROM AUTHOR]

Pheromone communication is widespread among animals. Since it is often involved in mate choice, pheromone production is often tightly controlled. Although male sex pheromones (MSPs) and anti-aphrodisiacs have been studied in some Heliconius butterfly species, little is known about the factors affecting their production and release in these long-lived butterflies. Here, we investigate the effect of post-eclosion age on chemical blends from pheromone-emitting tissues in Heliconius atthis and Heliconius charithonia, exhibiting respectively free-mating and pupal-mating strategies that are hypothesised to differently affect the timing of their pheromone emissions. We focus on two different tissues: the wing androconia, responsible for MSPs used in courtship, and the genital tip, the production site for anti-aphrodisiac pheromones that affect post-mating behaviour. Gas chromatography-mass spectrometric analysis of tissue extracts from virgin males and females of both species from day 0 to 8 post-eclosion demonstrates the following. Some ubiquitous fatty acid precursors are already detectable at day 0. The complexity of the chemical blends increases with age regardless of tissue or sex. No obvious difference in the time course of blend production was evident between the two species, but female tissues in H. charithonia were more affected by age than in H. atthis. We suggest that compounds unique to male androconia and genitals and whose amount increases with age are potential candidates for future investigation into their roles as pheromones. While this analysis revealed some of the complexity in Heliconius chemical ecology, the effects of other factors, such as the time of day, remain unknown. [ABSTRACT FROM AUTHOR]

The melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae), is considered to be the most destructive pest of melons and other related cucurbit crops worldwide. Despite the potential of behaviour-based control strategies, little is known about the mechanisms involved in female mate choice. Herein, we investigated the production and chemoreception of cuticular hydrocarbons in both sexes of Z. cucurbitae, and the behavioural responses they induce. We studied the epicuticular composition of virgin males and females, using two-dimensional gas chromatography coupled with mass spectrometric detection. Data were interpreted using multivariate factorial analysis. The differentiation of chemical profiles was consistently observed over time. In young individuals, the chemical profiles did not differ between sexes, while sex-specific differences were noted in mature flies. The fly olfactory sensitivity to these compounds was explored using gas chromatography combined with chopped triple electroantennography and electropalpography detectors. This extensive exploration of the pest olfactory sensitivity highlighted three compounds produced by the male. When blended, they induced a robust positive response in unmated naive females in a six-choice olfactometer. The responsiveness of other Tephritidae species (a polyphagous species Bactrocera dorsalis (Hendel) and the cucurbit specialist Dacus demmerezi (Bezzi)) to whole body extracts of Z. cucurbitae was also investigated. Our findings showed that Z. cucurbitae uses species-specific olfactory receptors to detect male produced compounds. In addition, the palps were sensitive to a female-specific component, 1,7-dioxaspiro[5.5]undecane, which the males produce in minute quantities. Overall, this study provides a starting point for a pheromone-based tephritid lure that targets unmated females. The potential implications for pest management are discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: The spotted lanternfly (SLF) is an invasive generalist that is spreading throughout the eastern United States. They feed in large aggregations, but the mechanisms they use to form these aggregations and find each other for mating are poorly understood. Laboratory evidence that they use pheromones is based on volatiles from their bodies and from honeydew excretions, but, due to their broad sensory capabilities, the pheromone components have been difficult to isolate and identify. This is the first evidence gathered in a field study that demonstrates, using naturally collected SLF odors as lures, that volatiles from SLF bodies and honeydew are both required to attract males at mating time and females during oviposition time. Using semiochemicals collected from spotted lanternflies Lycorma delicatula (Hemiptera: Fulgoridae) (SLF) and deployed in the field with circle traps, we demonstrated that SLF responded to SLF pheromones: in particular, this was the case for males while seeking mates and for females while ovipositing. The attractants consisted of SLF body extract emitted from diffuser lures and SLF honeydew on burlap ribbons, collected from heavily infested locations. Traps with attractants were deployed in field sites with very light SLF infestations to avoid competing signals of pre-existing aggregations. The number of SLF equivalents emitted by each diffuser per trapping period was used in a dose–response analysis. Three trees per block received either (1) a control hexane lure and a clean ribbon, (2) a lure containing SLF extract and a clean ribbon, or (3) a lure containing SLF extract and a honeydew-laden ribbon. Ten blocks were sampled three times per week for twelve weeks. We found a significant positive dose–response by males to SLF body extract only in the presence of SLF honeydew, indicating a synergistic effect between honeydew volatiles and body volatiles. This dose–response occurred for five weeks after mating started, after which males no longer responded. Subsequently, females had a significant positive dose–response to SLF extract only in the presence of honeydew when oviposition was their primary activity, continuing for two weeks, suggesting that females may use pheromones to aggregate for oviposition. The extract in the absence of honeydew did not result in a positive dose–response, nor did the hexane control. These findings suggest that SLF respond synergistically to the combination of pheromones present in both SLF honeydew and SLF bodies. Thus, combining key components from both sources may aid the development of semiochemical lures for SLF. [ABSTRACT FROM AUTHOR]

Simple Summary: This study aimed to investigate the function of the nuptial pad-secreted pheromone in anurans. By conducting transcriptome sequencing of the nuptial pads of the Yunnan pond frog, we obtained transcripts of protein pheromones that were highly expressed in the nuptial pads during the breeding season. These pheromones were homologous to the common frog amplexins and the plethodontid modulating factor (PMF) pheromone of urodeles. By means of recombinant protein expression, we obtained the single subtype of the pheromone and demonstrated its ability to shorten the duration of Yunnan pond frog pairing through behavioral experiments. The results of this study further confirm that urodeles and anurans share the PMF pheromone system. Additionally, this study validates the function of this pheromone in anurans for the first time, confirming that it serves similar functions as in urodeles, shortening the breeding process. Overall, this study provides a paradigm for exploring the function of pheromones in anurans. Chemical communication is an important mode of communication in the courtship and breeding processes of amphibians. In caudates, multiple components of sexual pheromones have been identified and functionally verified. One of these pheromone systems is plethodontid modulating factor (PMF). In anurans, the pheromone called amplexin was found in nuptial pads of ranids and was considered a member of the PMF system, yet its bio-function has not been tested. In this study, we obtained 18 amplexin transcript sequences from nuptial pads of Nidirana pleuraden (Amphibia, Ranidae) by transcriptome sequencing and found that the proteins translated by these transcripts are diversified, hydrophilic, and relatively stable. We also acquired a N. pleuraden amplexin isoform with the highest expression level in the transcriptome analysis through the prokaryotic expression system. Using two different animal behavioral experimental settings, we have tested the bio-function of the recombinant PMF protein (rPMF) in N. pleuraden's reproduction and found that the rPMF does not attract females but shortens the duration of amplexus significantly. This is the first study to verify the function of the PMF pheromone in Anura, indicating the pervasiveness of chemical communication during breeding in amphibians. [ABSTRACT FROM AUTHOR]

Simple Summary: If the existence of female sex pheromones in shrimp, Penaeus vannamei, is confirmed, they could be used to increase the larval production needed to supply shrimp farms worldwide. To gather more evidence of their existence, liposoluble compounds were extracted from the cuticle of different portions of the abdomen of adult females. These extracts were used to coat PVC tubes that were used as artificial females placed in tanks stocked with adult males. The males were monitored to determine if sexual behavior was displayed when in contact with the artificial females. The behavior observed in the shrimp males of this study provides evidence of the existence of sex pheromones located primarily in the ventral portion of the abdomen exoskeleton of shrimp females. Although the presence of female contact sex pheromones in P. vannamei has been hypothesized, to date its existence has not been proven. To gather more evidence of their existence, cuticular liposoluble extracts were obtained from the following samples of adult females to be used as the experimental treatments: (1) ventral exoskeleton of immature female (VI), (2) dorsolateral exoskeleton of immature female (DI), (3) ventral exoskeleton of mature female (VM), and (4) dorsolateral exoskeleton of mature female (DM). Polyvinyl chloride tubes (artificial females; AF) were coated with each extract and the behavior displayed by sexually mature males in contact with the AF was recorded and classified as follows: 0 = no response; 1 = contact; 2 = pushing; and 3 = prolonged contact (≥10 s). To test the hypothesis that the extracts collected from the ventral portion of the abdomen exoskeleton have a higher effect on the behavior of males than the extracts collected from the dorsolateral portion of the abdomen exoskeleton, the experiment was divided into two bioassays: Bioassay I (VI vs. DI) and Bioassay II (VM vs. DM). In each bioassay, all experimental treatments were significantly different (p > 0.05) from the CTL group (AF coated with hexane). Notably, the pushing behavior was significantly higher (p < 0.05) in the VI treatment compared to the CTL and DI treatment. These results provide evidence of the existence of contact female sex pheromones with sexual recognition function located primarily in the ventral portion of the abdomen exoskeleton of P. vannamei. [ABSTRACT FROM AUTHOR]

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BACKGROUND: Pheromones have unique advantages for pest control. Current aphid pheromone research focuses on alarm and sex pheromones. However, practical applications are limited so far, as (E)‐β‐farnesene has only been investigated to a small extent as an alarm pheromone and only male aphids are targeted by sex pheromones. Previous literature reports electrophysiological responses and repellent behavior of asexual aphids to nepetalactone (1B), therefore our objective was to modify nepetalactone's structure to identify key fragments responsible for repellent effects, as guidance for subsequent modifications and further investigation. RESULTS: In this study, seven derivatives were designed and synthesized based on nepetalactol (1A) and nepetalactone (1B) as lead compounds. Free‐choice tests, conducted using cowpea aphids (Aphis craccivora), revealed that the lactone moiety was crucial for the repellent activity, and the removal of the carbonyl group eliminated the repelling effect. Compound (±)1I, an analogue of nepetalactone (1B), demonstrated a significantly higher repellent value than nepetalactone (1B) at three different concentrations, and even at 0.1 mg/mL it maintained a considerable repellent effect (26.5%). Electrostatic potential and density functional theory calculations supported the importance of the carbonyl group for the repellent effects. CONCLUSION: The newly discovered para‐pheromone (±)1I shows improved repellent effects and potential for development as a novel biological control agent. Based on our innovative findings, analogues with improved efficacy and properties can be designed and prepared. Our research contributes to understanding the effects of structural modifications on pheromone activity and properties, which is crucial for exploring novel pheromone‐based products for crop protection. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: The stick tea thrips, Dendrothrips minowai Priesner, is one of the most important sucking pests that seriously infest tea plants (Camellia sinensis) in China. Given that D. minowai exhibit aggregation behaviors in tea plantations, this study evaluated the potential of aggregation pheromones for their control. RESULTS: H‐tube olfactometer assays showed that D. minowai larvae, adult females and adult males were significantly attracted to larvae rather than adult females and males under laboratory conditions. Subsequent gas chromatography–mass spectrometry analysis of volatiles from larvae, identified two larva‐specific components: dodecyl acetate and tetradecyl acetate. Electrophysiological and behavioral experiments confirmed the positive response of females and males to dodecyl acetate, tetradecyl acetate, and their blend (1:1.5). Deployment of these aggregation pheromones on sticky traps resulted in a 1.2‐ to 3.0‐fold increase in the capture of D. minowai adults compared with control traps. In addition, deployment of sticky traps baited with these aggregation pheromones within tea plantations resulted in a noteworthy reduction in the population of adult thrips per 100 leaves, 10 days following trap deployment. The reduction ranged from 29% to 59%, in comparison with the control. CONCLUSION: D. minowai larvae produce aggregation pheromones, dodecyl acetate and tetradecyl acetate, that can be useful for controlling tea thrips. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Fusaric acid (FA), a picolinic acid derivative, is a natural substance produced by a wide variety of fungal plant pathogens belonging to the Fusarium genus. As a metabolite, fusaric acid exerts several biological activities including metal chelation, electrolyte leakage, repression of ATP synthesis, and direct toxicity on plants, animals and bacteria. Prior studies on the structure of fusaric acid revealed a co-crystal dimeric adduct between FA and 9,10-dehydrofusaric acid. During an ongoing search for signaling genes differentially regulating FA production in the fungal pathogen Fusarium oxysporum (Fo), we found that mutants lacking pheromone expression have an increased production of FA compared to the wild type strain. Noteworthy, crystallographic analysis of FA extracted from Fo culture supernatants showed that crystals are formed by a dimeric form of two FA molecules (1:1 molar stoichiometry). Overall, our results suggest that pheromone signaling in Fo is required to regulate the synthesis of fusaric acid. [ABSTRACT FROM AUTHOR]

Pollination by sexual deception specifically attracts male insects, through the floral scent and particular morphological features of the flower that serve as visual and tactile stimuli. The unique bond between the Ophrys speculum orchid and the male Dasyscolia ciliata wasp primarily stems from a few distinctive semiochemicals that mimic the female wasp's sex pheromone, although the floral scent comprises a variety of compounds. An osmophore producing highly volatile compounds has been documented in four close relatives of O. speculum and is now being also investigated in this species. Given the existing debates regarding the structure of the labellum and stigmatic cavity in O. speculum, this study details their micromorphology. Additionally, comparisons of O. speculum flowers and female D. ciliata wasps under stereomicroscopy and scanning electron microscopy are conducted to seek new evidence of visual and tactile mimicry. The findings confirm that (i) an osmophore is present at the apical margin of the labellum in O. speculum flowers; (ii) the labellum features a distinct basal field homologous to those found in other Ophrys species; and (iii) the basal labellum region closely mimics the female wasp's thorax and wings. The implications of these novel floral features are discussed within an evolutionary context. [ABSTRACT FROM AUTHOR]