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Great Salt Lake (GSL), located northwest of Salt Lake City, UT, is the largest terminal lake in the USA. While the average salinity of seawater is ~3.3%, the salinity in GSL ranges between 5% and 28%. In addition to being a hypersaline environment, GSL also contains toxic concentrations of heavy metals, such as arsenic, mercury, and lead. The extreme environment of GSL makes it an intriguing subject of study, both for its unique microbiome and its potential to harbor novel natural product-producing bacteria, which could be used as resources for the discovery of biologically active compounds. Though work has been done to survey and catalog bacteria found in GSL, the Lakes microbiome is largely unexplored, and little to no work has been done to characterize the natural product potential of GSL microbes. Here, we investigate the bacterial diversity of two important regions within GSL, describe the first genomic characterization of Actinomycetota isolated from GSL sediment, including the identification of two new Actinomycetota species, and provide the first survey of the natural product potential of GSL bacteria.

Premise Methods Results Conclusions Volatile emissions from flowers and fruits play a key role in signalling to animals responsible for pollination and seed dispersal. Here, we investigated the pollination biology and chemical ecology of reproduction in Apodolirion buchananii, an African amaryllid that flowers in a leafless state soon after grassland vegetation is burnt in the dry late‐winter season.Pollinators were identified through field collection and pollen loads were quantified. Floral traits including spectral reflectance and scent chemistry were documented. Bioassays using cup traps were used to test the function of floral volatiles. Fruiting biology was investigated using controlled hand‐pollination experiments and chemical analysis of fruit scent. Seed germination was scored in greenhouse trials. Seed dispersal was monitored using observations and camera trapping.The sweetly scented white flowers of A. buchananii are pollen‐rewarding and pollinated mainly by a diverse assemblage of bees. Cup‐trap experiments demonstrated that pollinators are attracted to phenylacetaldehyde, the dominant volatile in the floral scent. Plants are shown to be self‐incompatible, and the fleshy fruits were found to emerge from the soil six months after pollination during the peak of the summer rains. Fruits emit a diverse blend of aliphatic and aromatic esters and contain large fleshy recalcitrant seeds which germinate within days of fruits splitting open. Seed dispersal by ants was recorded.This first account of the reproductive biology of a species in the genus Apodolirion highlights an outcrossing mating system involving bees attracted to color and scent as well as the unusual fruiting biology and ant‐mediated system of seed dispersal. [ABSTRACT FROM AUTHOR]

Inter-kingdom communication through small molecules is essential to the coexistence of organisms in an ecosystem. In soil communities, the plant root is a nexus of interactions for a remarkable number of fungi and is a source of small-molecule plant hormones that shape fungal compositions. Although hormone signaling pathways are established in plants, how fungi perceive and respond to molecules is unclear because many plant-associated fungi are recalcitrant to experimentation. Here, we develop an approach using the model fungus, Saccharomyces cerevisiae , to elucidate mechanisms of fungal response to plant hormones. Two plant hormones, strigolactone and methyl jasmonate, produce unique transcript profiles in yeast, affecting phosphate and sugar metabolism, respectively. Genetic analysis in combination with structural studies suggests that SLs require the high-affinity transporter Pho84 to modulate phosphate homeostasis. The ability to study small-molecule plant hormones in a tractable genetic system should have utility in understanding fungal-plant interactions. [Display omitted] • The plant hormone strigolactone hijacks phosphate metabolism in baker's yeast • Strigolactone allosterically inhibits the high-affinity phosphate transporter Pho84 • A conserved transmembrane pocket in Pho84 is required for strigolactone function • Strigolactone modulates phosphate homeostasis in plant-associated fungi Strigolactones act as both plant hormones and as environmental communication signals to plant-associated fungi. Bradley et al. show that strigolactone modulates phosphate homeostasis in baker's yeast by antagonizing the phosphate transporter Pho84. This strigolactone response is conserved in other fungi, suggesting that yeast will facilitate our understanding of natural plant-fungal communication. [ABSTRACT FROM AUTHOR]

In Mexico, Triatoma pallidipennis is a major vector of Trypanosoma cruzi, the causative agent of Chagas disease. Current efforts are focused on developing attractants to control these vectors, using volatile substances derived from vertebrate hosts or compounds known to attract hematophagous insects. However, the efficacy of these compounds in attracting parasite‐infected triatomines remains to be evaluated. In this study, we assessed the attractant activity of octenol (1‐octen‐3‐ol), nonanal and a mixture of odorants consisting of ammonium hydroxide, lactic acid and hexanoic acid (in a ratio of 1:0.2:0.4 respectively), at concentrations of 1, 10 and 100 ng on the N3, N4 and N5 nymphal stages of T. pallidipennis, both infected and non‐infected with T. cruzi. We also evaluated the synergistic effect of the most effective compounds and doses. All experiments were performed in a laboratory using a Y‐type glass olfactometer. We found that both infected and non‐infected N3 and N4 nymphs were attracted to low doses of octenol, nonanal and the odorant mixture. Particularly noteworthy was the synergistic effect observed between the odorant mixture and nonanal, which significantly increased attraction of T. cruzi–infected individuals. These findings contribute to the development of baited traps utilising these compounds for monitoring triatomines in epidemiological studies or for mass trapping to control these vectors. [ABSTRACT FROM AUTHOR]

Plants produce a great number of phytochemicals serving a variety of different functions. Recently, the chemodiversity of these compounds (i.e., the diversity of compounds produced by a plant) has been suggested to be an important aspect of the plant phenotype that may shape interactions between plants, their environment, and other organisms. However, we lack an agreement on how to quantify chemodiversity, which complicates conclusions about the functional importance of it. Here, we discuss how chemodiversity (deconstructed into components of richness, evenness and disparity) may relate to different ecologically relevant aspects of the phenotype. Then, we systematically review the literature on chemodiversity to examine methodological practices, explore patterns of variability in diversity across different levels of biological organization, and investigate the functional role of this diversity in interactions between plants and other organisms. Overall, the reviewed literature suggests that high chemodiversity is often beneficial for plants, although a heterogeneity of methodological approaches partly limits what general conclusions can be drawn. Importantly, to support future research on this topic, we provide a framework with a decision tree facilitating choices on which measures of chemodiversity are best used in different contexts and outline key questions and avenues for future research. A more thorough understanding of chemodiversity will provide insights into its evolution and functional role in ecological interactions between plants and their environment. [ABSTRACT FROM AUTHOR]

Volatile compounds in floral nectar may affect plant–pollinator relationships; however, the understanding of the distribution and functions of scented floral nectar is still relatively limited. In this study, we examined the volatile constituents of the scented floral nectar of the black lily Fritillaria camtschatcensis and their potential to attract flower‐visiting flies. In Japan, F. camtschatcensis comprises two varieties, var. camtschatcensis (lowland) and var. keisukei (alpine). The flowers of both varieties secrete large amounts of nectar that is fed on by visiting flies. We investigated the sugar concentration of the nectar using high‐performance liquid chromatography (HPLC) and studied its volatile chemical composition using gas chromatography–mass spectrometry. We conducted a bioassay using a synthetic mixture of nectar volatiles of the lowland variety to test whether flies are attracted to volatile compounds in the nectar scent. HPLC analysis showed that glucose and fructose occur in the nectar of the alpine variety, whereas the lowland variety nectar contained glucose but lacked fructose. Nectar volatile compounds differed substantially between the two varieties; the volatiles of the lowland variety consisted primarily of four aliphatic acids, whereas acetophenone was the main volatile compound in the alpine variety. The bioassay showed that a mixture of three aliphatic acids detected as volatiles of the lowland variety nectar attracts flies, including those that visit the alpine variety flowers such as Calliphoridae. These results suggest that the volatiles of the scented nectar serve as attractants for flower visitors and may have an important role in the pollination of F. camtschatcensis. [ABSTRACT FROM AUTHOR]

The recognition of cerambycids as frequent and damaging invaders led to an increase in the interest in the chemical ecology of the group with the identification of pheromones and pheromone-like attractants for well over 100 species. Pheromone components of the Cerambycidae are often phylogenetically conserved, with a single compound serving as a pheromone component for several related species. In the subfamily Lamiinae, the compound 2-(undecyloxy)ethanol (monochamol) has been identified as an aggregation-sex pheromone for several species of the genus Monochamus. In other species, including Monochamus maculosus Haldeman, field trials have demonstrated that monochamol is a pheromone attractant, but at that point it was still unknown as to whether it was a pheromone for this species. Here we report the identification, and laboratory and field trials of a pheromone component produced by adult male M. maculosus. Chemical analyses of headspace volatile collections sampled from field collected beetles of both sexes revealed the presence of one male-specific compound that was identified as 2-(undecyloxy)ethanol. Electroantennography analyses showed that monochamol elicited responses from the antennae of female beetles. Traps baited with monochamol in the field captured M. maculosus adults of both sexes corroborating the identification of monochamol as the sex-aggregation pheromone of this species. The attractivity of monochamol to adult M. maculosus in our field trapping experiment was synergized by the addition of the host volatile α-pinene. [ABSTRACT FROM AUTHOR]

Tsetse flies (Diptera: Glossinidae) are the cyclical vectors of human and animal trypanosomes. This viviparous insect develops and produces a single larva at 10-day intervals deposited in specific sites. In some species aggregation of larvae has been shown and seems to be mediated by both physical factors and volatile semiochemicals of larval origin. In this context, this study aims to identify chemicals emitted during the pupariation process in Glossina palpalis gambiensis. Volatile Organic Compounds (VOCs) emitted by larvae were identified using static headspace solid-phase microextraction and gas-chromatography mass-spectrometry (GC–MS) analysis. Electrophysiology and behavioural assays were performed on gravid females to confirm VOCs behavioural activity and attractiveness. GC–MS results revealed ten chemicals emitted during the pupariation process of G. p. gambiensis larvae. Among these chemicals, gravid females were shown to detect nine of them during coupled gas chromatography - electroantennographic detection tests. Behavioural assays highlighted two compounds were as attractive as pupae and one compound and a blend of four compounds were more attractive than pupae. Although the larval origin of some of them needs to be confirmed as they may also likely produced by micro-organisms, these compounds induced significant behavioural responses in the laboratory. Further experiments have to explore the biological activity and competitiveness of these compounds in the field. This work opens interesting opportunities for behavioural manipulation and control of tsetse flies. [ABSTRACT FROM AUTHOR]

Animals that consume toxic diets provide models for understanding the molecular and physiological adaptations to ecological challenges. Garter snakes (Thamnophis) in western North America prey on Pacific newts (Taricha), which employ tetrodotoxin (TTX) as an antipredator defense. These snakes possess mutations in voltage-gated sodium channels (Nav), the molecular targets of TTX, that decrease the binding ability of TTX to sodium channels (target-site resistance). However, genetic variation at these loci that cannot explain all the phenotypic variation in TTX resistance in Thamnophis. We explored a separate means of resistance, toxin metabolism, to determine if TTX-resistant snakes either rapidly remove TTX or sequester TTX. We examined the metabolism and distribution of TTX in the body (toxicokinetics), to determine differences between TTX-resistant and TTX-sensitive snakes in the rates at which TTX is eliminated from organs and the whole body (using TTX half-life as our metric). We assayed TTX half-life in snakes from TTX-resistant and TTX-sensitive populations of three garter snake species with a coevolutionary history with newts (T. atratus, T. couchii, T. sirtalis), as well as two non-resistant "outgroup" species (T. elegans, Pituophis catenifer) that seldom (if ever) engage newts. We found TTX half-life varied across species, populations, and tissues. Interestingly, TTX half-life was shortest in T. elegans and P. catenifer compared to all other snakes. Furthermore, TTX-resistant populations of T. couchii and T. sirtalis eliminated TTX faster (shorter TTX half-life) than their TTX-sensitive counterparts, while populations of TTX-resistant and TTX-sensitive T. atratus showed no difference rates of TTX removal (same TTX half-life). The ability to rapidly eliminate TTX may have permitted increased prey consumption, which may have promoted the evolution of additional resistance mechanisms. Finally, snakes still retain substantial amounts of TTX, and we projected that snakes could be dangerous to their own predators days to weeks following the ingestion of a single newt. Thus, aspects of toxin metabolism may have been key in driving predator–prey relationships, and important in determining other ecological interactions. [ABSTRACT FROM AUTHOR]

Host specificity is a key criterion for the implementation of any biological control program. In parasitoid wasps, host specificity is mediated by their response to chemical cues directly and indirectly associated with their hosts during foraging. Although intraspecific variation in foraging behaviour is documented, it is rarely integrated into risk assessment studies of potential biological control agents, as is the case for Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), an Asian egg parasitoid and biological control agent of the invasive Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). In the present study, we compared the behavioural response of T. japonicus females of an adventive line present in Switzerland and an Asian line (Beijing USDA), recently mass released in Italy, to cues of its target host H. halys and non-target host Pentatoma rufipes (L.) (Hemiptera: Pentatomidae). We observed minimal differences in host acceptance, exploitation and suitability in no-choice tests. In contrast, the behavioural response to host contact kairomones left on leaf substrates significantly differed between the two lines. While both lines preferred chemical footprints of H. halys in comparison to P. rufipes, females of the Beijing USDA line responded more strongly to host kairomones. The observed intraspecific variation in behavioural traits highlights the relevance of considering genetically distinct parasitoid lines and their host foraging behaviour in biological risk assessment studies. However, the implications of intraspecific variation in parasitoid foraging behaviour for biological control of a pest and non-target effects in the field remain challenging to predict. [ABSTRACT FROM AUTHOR]

Sclerodermus cereicollis is a European flat wasp ectoparasitoid of some longhorn beetle species. This species is important as a suitable biological control agent against xylophagous pests. To better understand its chemical ecology, the ultrastructure of the antennal sensilla of the adult was studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The sensilla are located mainly in the ventro‐medial side of the antennae. We report a clearly sexual dimorphism with respect to antennae length, and to types, number, and distribution of chemosensilla. The antennae in males are significantly longer than those of females. We describe in detail the external and internal structure of different chemoreceptors represented by sensilla placodea, long sensilla basiconica, multiporous sensilla chaetica, grooved sensilla ampullacea, uniporous grooved sensilla chaetica. The potential involvement of the different kinds of chemoreceptors in inter‐ (mainly sexual recognition and social behavior‐kin recognition) or intra‐specific communication (mainly host selection) is discussed on the basis of behavioral and electrophysiological investigations performed on other parasitoid species belonging to the same family. Other sensilla with morphology that is not consistent with that of chemoreceptors are represented by grooved pegs, coeloconic pegs, trichoid sensilla. Such detailed ultrastructural investigation of the flagellar chemoreceptors of S. cereicollis, clarifying the number of chemosensory neurons innervating the different sensilla, is crucial for further electrophysiological investigations on this important species. Research Highlights: Evident sexual dimorphism concerning antennae length, type, number, and distribution of chemosensilla.Long sensilla basiconica (LSB) present only in females could play a role in host location and/or maternal care.Multiporous sensilla chaetica (MSC), significantly longer and mostly represented in males, could play a role in the perception of sexual pheromones.Detailed ultrastructural study is crucial for electrophysiological investigations on this important species. [ABSTRACT FROM AUTHOR]

Semiochemicals are dominant cues for insects to locate food, mates, predators, and oviposition sites. In the modern genomic era, semiochemicals have been identified not only by the conventional chemical ecology based on bioassay-guided protocols but also by reverse chemical ecology started with deorphanization of olfactory proteins with high olfactory sensitivity and selectivity. The Scarab beetle, Anomala corpulenta, is a polyphagous pest, posing a substantial economic burden to agricultural, horticultural, and forestry industries. Here, we focused on four odorant receptors (ORs) abundantly expressed in the antennae. We heterologously expressed them in Xenopus oocytes and examined their responses to a panel of 22 odorants. Of the ORs, AcorOR29 was specifically tuned to a common floral compound, phenethyl propionate (PEP). Further, gas chromatography coupled with electroantennographic detection showed that PEP elicited a strong electrophysiological response from antennae. Y-tube olfactometer assay and field trap experiment demonstrated that PEP is attractive for both sexes of A. corpulenta across a wide range of concentrations, potentiating PEP in practical applications. Our results show that the reverse chemical ecology approach is effective in identifying semiochemicals for A. corpulenta, which would help to formulate novel strategies to control this pest. [ABSTRACT FROM AUTHOR]

The genus Agrilus is one of the most diverse insect genera worldwide. The larval feeding activity causes extensive damage in both forests and orchards. In addition, more than 30 species have been introduced outside their native range so far, including the emerald ash borer Agrilus planipennis Fairmaire. Thus, the availability of efficient trapping protocols for early detection of Agrilus species at entry points is of utmost importance. In this study we tested whether trapping protocols developed for surveillance of A. planipennis in North America were also effective for other Agrilus species. In particular, through a multi-country assessment we compared the efficacy of detecting Agrilus species on: (i) green glue-coated prism traps vs. green Fluon-coated multi-funnel traps when baited with the green leaf volatile (Z)-3-hexenol or left unbaited; and (ii) green multi-panel traps vs. green multi-panel traps baited with dead adult Agrilus beetles (decoys). A total of 23,481 individuals from 45 Agrilus species were caught. Trap design significantly affected both species richness and abundance of Agrilus species in several of the countries where the trapping experiments were carried out, and green prism traps outperformed green multi-funnel traps in most cases. On the contrary, the addition of a (Z)-3-hexenol lure or dead adult beetle decoys on to traps did not improve trap catches. Our study highlights that reliable trap models to survey Agrilus species are already available, but also that there is the clear need to further investigate chemical ecology of Agrilus species to develop semiochemical lures that can improve detection efficacy. [ABSTRACT FROM AUTHOR]

Associational effects, whereby plants influence the biotic interactions of their neighbors, are an important component of plant–insect interactions. Plant chemistry has been hypothesized to mediate these interactions. The role of chemistry in associational effects, however, has been unclear in part because the diversity of plant chemistry makes it difficult to tease apart the importance and roles of particular classes of compounds. We examined the chemical ecology of associational effects using backcross‐bred plants of the Solanum pennellii introgression lines. We used eight genotypes from the introgression line system to establish 14 unique neighborhood treatments that maximized differences in acyl sugars, proteinase inhibitor, and terpene chemical diversity. We found that the chemical traits of the neighboring plant, rather than simply the number of introgression lines within a neighborhood, influenced insect abundance on focal plants. Furthermore, within‐chemical class diversity had contrasting effects on herbivore and predator abundances, and depended on the frequency of neighboring plant chemotypes. Notably, we found insect mobility—flying versus crawling—played a key role in insect response to phytochemistry. We highlight that the frequency and chemical phenotype of plant neighbors underlie associational effects and suggest this may be an important mechanism in maintaining intraspecific phytochemical variation within plant populations. [ABSTRACT FROM AUTHOR]

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]

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]

This document discusses the importance of chemical ecology in forest ecosystems. It highlights the role of chemical relationships in the interactions between organisms and the impact on plant growth, reproduction, and defense strategies. The document also explores the use of allelopathy, the production of allelochemicals by plants, to enhance plant productivity and resistance to pests. Additionally, it examines the influence of chemical signaling substances on plant growth and the role of soil microbial communities in nutrient availability. The document concludes by discussing the effects of environmental factors on the production of active substances in plants and the impact of nutrient imbalances on plant health. Overall, this document provides valuable insights into the study of forest chemical ecology and its implications for sustainable forest development. [Extracted from the article]

Piper mollicomum Kunth (Piperaceae) plays a vital role in the preservation of the Brazilian Atlantic Forest by contributing to the regeneration of deforested areas. Recent scientific investigations have analyzed the chemical constituents and seasonal dynamics of essential oils (EO) from various Piper L. species, highlighting the need to elucidate their chemical–ecological interactions. This study aims to expand the chemical–ecological knowledge of this important taxon in neotropical forests, using P. mollicomum as a model. The methodologies employed include the collection of plant material, EO extraction by hydrodistillation, analysis of EO by gas chromatography–mass spectrometry (GC–MS) and gas chromatography–flame ionization detector (GC–FID), recording the frequency of visits by potential pollinators and microclimatic variables, and by conducting calculations of chemodiversity and chemophenetic indices. Chemical analyses indicated that the diversity of EO and environmental factors are linked to the activities of potential pollinators. In the Tijuca Forest, P. mollicomum revealed significant interactions between its volatile constituents and microclimatic variables, showing that the chemodiversity of the leaves and reproductive organs correlates with pollinator visitation. Additionally, a notable difference in chemical evenness was observed between these vegetative structures. The chemophenetic indices by Ramos and Moreira also revealed correlations with chemical diversity. [ABSTRACT FROM AUTHOR]

Pollinators seek high quality nectar and pollen rewards critical for their growth and reproduction. Volatile emissions from inflorescences may signal plant health and floral resource quality to these flower-visiting insects. To understand the relationship between floral volatile emission and pollinator preference in a field setting, we conducted a replicated garden experiment consisting of 18 native perennial species from three different plant families with varying nutritional resource quality. We collected flower-visiting insects and floral volatile emissions over two field seasons, detecting over 60 volatile compounds and over 150 insect species. We collated trait data of visiting insects (bee or non-bee, body size, degree of sociality, nesting behavior, and whether the visitor was non-native) and evaluated interactions between these traits and volatile composition. Among the insect traits, bees and larger visitors had negative associations with sesquiterpenes, while in contrast visitors with complex nesting behaviors and social insects had positive associations. When comparing plant traits with bee traits, bee visitors had negative associations with purple inflorescences and larger insects and social insects both had positive associations with yellow inflorescences. We tested for direct associations between volatile class and insect taxa and found that sesquiterpenes had a strong positive relationship with hoverfly presence. This work demonstrates the complexity of floral volatiles as signals for pollinating insects and how floral scent composition allows individual compounds to act synergistically or antagonistically. These results can help us to better understand pollinator preferences and visitation patterns in the broad context of chemical ecology. [ABSTRACT FROM AUTHOR]

Abstract Key Message Medetera (Fischer von Waldheim) flies, natural enemies of the spruce bark beetle Ips typographus (L.), were attracted to synthetic blends of compounds produced by infested spruce trees. A subset of trapped specimens revealed sixteen Medetera species. Most abundant were M. signaticornis, M. infumata, and M. prjachinae. Only blends containing beetle-produced compounds significantly attracted Medetera spp. and I. typographus. Context Fly species of the genus Medetera (Fischer von Waldheim) (Diptera: Dolichopodidae) represent one of the most important groups of natural enemies of the Eurasian bark beetle Ips typographus (L.), which infests Norway spruce Picea abies (L.) Karst. In a previous study, we showed that adult Medetera flies exploit semiochemicals to find beetle-infested trees however, the exact nature of those attractive compounds has not yet been determined. Aims The aim of this follow-up study was to investigate the behavioral responses of Medetera spp. and I. typographus, to different combinations of semiochemicals. Methods In this study, 22 volatile compounds identified from I. typographus-infested Norway spruce were divided into five groups (A–E) based on being primarily produced by the bark beetle I. typographus (group A), bark beetle-associated microorganisms (groups B and C), or spruce tree (groups D and E). The effect of the compounds in these groups in the attraction of Medetera species and I. typographus was tested in two different subtractive field trapping assays. Results In the first subtractive assay, the full blend (ABCDE), and the blends lacking microbial compounds of group C, or spruce tree compounds of group D led to significant attraction of Medetera flies. Morphological identification of a subset of the specimens collected revealed that sixteen species were attracted to the synthetic blends, with M. signaticornis Loew being the most abundant. In the second subtractive assay, high attraction of Medetera flies and I. typographus was found for a 12-component synthetic blend. Conclusion The insights gained provide a basis for developing synthetic attractants to facilitate monitoring of Medetera flies. Future testing and optimization of these attractants will enhance our ability to monitor, conserve and utilize Medetera flies, thereby enabling us to better protect forests from the damaging effects of spruce bark beetles.

The fruit-piercing moth (FPM) Eudocima phalonia is widely present in the tropics, causing major damages to the citrus industry. In its ancestral distribution range, e.g. Australia, FPM develops on vines from the Menispermaceae family. But in more recently colonized islands, e.g. New Caledonia, FPM populations have shifted to new host plants of the Fabaceae family, Erythrina spp.. To understand this host shift, we studied the chemical ecology of FPM as a mechanism driving host plant acceptance. We collected volatile headspace samples of Erythrina species and Menispermaceae and compared their chemical spectra. We assessed the electrophysiological responses of FPM populations from the two countries to the plant chemical extracts and identified bioactive compounds. The volatile profiles from each species were quite different between and within each plant family. However, five compounds common across the two families triggered electrophysiological responses in both FPM populations. Those common bioactive compounds could have facilitated the host shift to completely different plant family. Furthermore, the diverging history between the two FPM populations may explain differences in electrophysiological sensitivity to other specific compounds. These results are discussed in the context of the production of a generic lure that could be attractive to all FPM populations. [ABSTRACT FROM AUTHOR]

Insects play crucial roles in nearly every ecosystem and provide a wide array of ecosystem services. However, both managed and wild insect populations face threats from parasites and pathogens, which require surveillance to mitigate. Current infectious disease surveillance methods for insects often involve invasive, time‐consuming and occasionally destructive techniques, such as manual inspections and molecular detection. Volatile organic compound (VOC) surveillance provides a real‐time, accurate and non‐invasive alternative for disease detection and has been well‐established in humans and livestock. Recent advances in sensor technology now allow for the development of in‐field VOC surveillance devices. This review explores the need for disease surveillance in insects and highlights recent advances of using VOCs for this purpose, focusing on honey bees as an example. We outline potential applications, challenges and future prospects of using VOCs for insect disease surveillance, providing examples of how this technology could be globally applied to mitigate the impacts of disease in a range of insect systems. [ABSTRACT FROM AUTHOR]

Sawfly species of the genus Monophadnus are specialised on Ranunculaceae plants from which the larvae can sequester furostanol saponins into the haemolymph, mainly (25R)-26-[(α-L-rhamnopyranosyl)oxy]-22α-methoxyfurost-5-en-3β-yl-O-β-D-glucopyranosyl-(1→3)-O-[6-acetyl-β-D-glucopyranosyl-(1→3)]-O-β-D-glucopyranoside (compound 1). In this work, TLC, GC-MS, and HPLC-DAD-ESI/MS analyses together with feeding, repeated simulated attacks, and ant deterrence bioassays were conducted to extend the chemoecological knowledge about two sawfly species specialised on H. foetidus L. (Monophadnus species A) and H. viridis L. (Monophadnus species B). Larvae of Monophadnus species B were mostly feeding on the squares treated with the n-butanol fraction from H. foetidus, compound 1 being its primary non-nutritional stimulant. In contrast, all H. viridis fractions stimulated feeding, with n-hexane marginally more active. β-sitosterol within n-hexane was determined as the nutritional stimulant. Quantitative analyses demonstrated that leaves of H. viridis but not H. foetidus contain the ecdysteroids 20-hydroxyecdysone and polypodine B. Moreover, the haemolymph of Monophadnus species B larvae reared on H. viridis contained the glycosides of polypodine B and 20-hydroxyecdysone at a concentration of 2.5 to 6.8 µmol/g fresh weight of haemolymph. This concentration is several thousand times higher than the concentration range of the aglycones in their host plant (3.63 × 10−4 to 2.23 × 10−4 µmol total ecdysteroids/g fresh weight of leaves), suggesting bioaccumulation. The larvae of both species fed on H. foetidus do not show any traces of ecdysteroids in their haemolymph, indicating a facultative role of these compounds in their defence as well as their inability to endogenously synthesise these compounds. The haemolymph containing ecdysteroids was a significant feeding deterrent against Myrmica rubra L. ant workers (one of their natural predators) at 0.8 mg/mL. The larvae kept effective deterrent levels of glycosylated ecdysteroids (≅175 mM) between simulated attacks on days 1 and 2, but the levels clearly decreased on day 3 (≅75 mM). Most larvae (89%) survived a first attack but only 23% a consecutive second one. As a conclusion, we report for the first time that two Monophadnus species feeding on H. viridis sequester phytoecdysteroids into the larval haemolymph in the form of glycosides. In addition, compound 1 possesses defensive and phagostimulant activities, and we present evidence for a combined effect of furostanol saponins and ecdysteroids as repellents against ants. [ABSTRACT FROM AUTHOR]

The ecological interaction between fleshy fruits and frugivores is influenced by diverse mixtures of secondary metabolites that naturally occur in the fruit pulp. Although some fruit secondary metabolites have a primary role in defending the pulp against antagonistic frugivores, these metabolites also potentially affect mutualistic interactions. The physiological impact of these secondary metabolites on mutualistic frugivores remains largely unexplored. Using a mutualistic fruit bat (Carollia perspicillata), we showed that ingesting four secondary metabolites commonly found in plant tissues affects bat foraging behavior and induces changes in the fecal metabolome. Our behavioral trials showed that the metabolites tested typically deter bats. Our metabolomic surveys suggest that secondary metabolites alter, either by increasing or decreasing, the absorption of essential macronutrients. These behavioral and physiological effects vary based on the specific identity and concentration of the metabolite tested. Our results also suggest that a portion of the secondary metabolites consumed is excreted by the bat intact or slightly modified. By identifying key shifts in the fecal metabolome of a mutualistic frugivore caused by secondary metabolite consumption, this study improves our understanding of the effects of fruit chemistry on frugivore physiology. [ABSTRACT FROM AUTHOR]

Eusocial insects, such as ants and termites, are characterized by high levels of coordinated social organization. This is contrasted by solitary insects that display more limited forms of collective behavior. It has been hypothesized that this gradient in sociobehavioral sophistication is positively correlated with chemical profile complexity, due to a potentially increased demand for diversity in chemical communication mechanisms in insects with higher levels of social complexity. However, this claim has rarely been assessed empirically. Here, we compare different levels of chemical and transcriptomic complexity in selected species of the order Blattodea that represent different levels of social organization, from solitary to eusocial. We primarily focus on cuticular hydrocarbon (CHC) complexity, since it has repeatedly been demonstrated that CHCs are key signaling molecules conveying a wide variety of chemical information in solitary as well as eusocial insects. We assessed CHC complexity and divergence between our studied taxa of different social complexity levels as well as the differentiation of their respective repertoires of CHC biosynthesis gene transcripts. Surprisingly, we did not find any consistent pattern of chemical complexity correlating with social complexity, nor did the overall chemical divergence or transcriptomic repertoire of CHC biosynthesis genes reflect on the levels of social organization. Our results challenge the assumption that increasing social complexity is generally reflected in more complex chemical profiles and point toward the need for a more cautious and differentiated view on correlating complexity on a chemical, genetic, and social level. [ABSTRACT FROM AUTHOR]

Living organisms use substrate-borne vibrations for interacting with their environment, where vibrational signals and cues can evoke a diverse range of responses, leading to benefits or detriments for the sender and/or receiver based on the context. Vibrational signals mediate a variety of animal behaviors, and, notably, plants can gain crucial information by detecting vibrations caused by herbivores, sometimes resulting in the establishment of mutualistic interactions with insects. Drawing inspiration from the terminology established in chemical ecology, we propose the introduction of the terms 'pherodones' for intraspecific interactions and 'allelodones' for interspecific interactions. Living organisms use both chemical and mechanical stimuli to survive in their environment. Substrate-borne vibrations play a significant role in mediating behaviors in animals and inducing physiological responses in plants, leading to the emergence of the discipline of biotremology. Biotremology is experiencing rapid growth both in fundamental research and in applications like pest control, drawing attention from diverse audiences. As parallels with concepts and approaches in chemical ecology emerge, there is a pressing need for a shared standardized vocabulary in the area of overlap for mutual understanding. In this article, we propose an updated set of terms in biotremology rooted in chemical ecology, using the suffix '-done' derived from the classic Greek word 'δονέω' (pronounced 'doneo'), meaning 'to shake'. [ABSTRACT FROM AUTHOR]

Microorganisms consume and transform dissolved organic matter (DOM) into various forms. However, it remains unclear whether the ecological patterns and drivers of DOM chemodiversity are analogous to those of microbial communities. Here, a large-scale investigation is conducted along the Chinese coasts to resolve the intrinsic linkages among the complex intertidal DOM pools, microbial communities and environmental heterogeneity. The abundance of DOM molecular formulae best fits log-normal distribution and follows Taylor's Law. Distance-decay relationships are observed for labile molecular formulae, while latitudinal diversity gradients are noted for recalcitrant molecular formulae. Latitudinal patterns are also observed for DOM molecular features. Negative cohesion, bacterial diversity, and molecular traits are the main drivers of DOM chemodiversity. Stochasticity analyses demonstrate that determinism dominantly shapes the DOM compositional variations. This study unveils the intrinsic mechanisms underlying the intertidal DOM chemodiversity and microbial communities from ecological perspectives, deepening our understanding of microbially driven chemical ecology. Intertidal DOM follows similar ecological patterns and underlying mechanisms to microbes, suggesting that there may exist universal ecological models explaining the patterns of both living and non-living biological entities in the Earth's biosphere. [ABSTRACT FROM AUTHOR]

Pear psylla, Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae), occurs as 2 seasonal morphotypes. Summerforms occur on pear (Pyrus communis L.; Rosales: Rosaceae) where they are a significant pest. The larger and darker winterform morphotype develops in response to shortening daylengths and begins winter in reproductive diapause characterized by the absence of ovarian development. Diapausing winterforms often leave pear to overwinter on coniferous shelter plants and then return to pear in late winter and early spring to begin depositing the eggs that produce the first summerform generation. Cacopsylla pyricola adults are attracted to the color of foliage most of the year, but little is known about the role of plant volatiles in host finding and in seasonal dispersal between host and shelter plants by the psyllid. We used a Y-tube olfactometer and choice assays to investigate the response by C. pyricola adults to volatiles emitted by pear and an evergreen tree (cypress) often used as a shelter plant by wintering C. pyricola. Attraction to pear and cypress volatiles varied by season, tree phenology, and psyllid physiology. Cacopsylla pyricola were attracted to cypress volatiles and preferred to settle on cypress shoots during winter and early spring but then shifted to a marked preference for the pear developmental host in late spring and summer. Female C. pyricola exhibited stronger responses to pear volatiles than did males. Our study is the first to show that plant volatiles have a role in host finding by C. pyricola and provides a foundation for research on chemical ecology and management of C. pyricola. [ABSTRACT FROM AUTHOR]

Sirex noctilio is an invasive forest wasp that affects pines in many parts of the globe and can result in severe economic losses. Current trapping methods for monitoring the pest rely heavily on non‐specific semiochemicals. This lack of specificity can translate into low attraction/capture levels, something that is undesired, especially when the intent is to detect the pest when still at low population densities. In this context, an interesting opportunity arises to increase trap sensitivity by incorporating visual cues. For this, we evaluated potential sources of visual information that, in accordance with the ecology of the species, could elicit an attractive response complementary to the olfactory cues. We measured the reflectance spectra of pine bark, chlorotic needles and woodwasp male abdomens. The spectra were then compared with 120 commercial paint colours to be applied on panel traps. During two flight seasons, field experiments were conducted with the deployment of 155 traps, combining the volatile bait (turpentine) and different coloured traps. We observed a significantly higher number of captures towards traps with pine bark‐like colourations compared with the black control traps. Our results are encouraging, as they suggest the potential of combining visual and chemical information for sustainable pest biomonitoring. [ABSTRACT FROM AUTHOR]

Chemical information has become increasingly ubiquitous and has outstripped the pace of analysis and interpretation. We have developed an R package, uafR, that automates a grueling retrieval process for gas -chromatography coupled mass spectrometry (GC -MS) data and allows anyone interested in chemical comparisons to quickly perform advanced structural similarity matches. Our streamlined cheminformatics workflows allow anyone with basic experience in R to pull out component areas for tentative compound identifications using the best published understanding of molecules across samples (pubchem.gov). Interpretations can now be done at a fraction of the time, cost, and effort it would typically take using a standard chemical ecology data analysis pipeline. The package was tested in two experimental contexts: (1) A dataset of purified internal standards, which showed our algorithms correctly identified the known compounds with R2 values ranging from 0.827–0.999 along concentrations ranging from 1 × 10−5 to 1 × 103 ng/μl, (2) A large, previously published dataset, where the number and types of compounds identified were comparable (or identical) to those identified with the traditional manual peak annotation process, and NMDS analysis of the compounds produced the same pattern of significance as in the original study. Both the speed and accuracy of GC -MS data processing are drastically improved with uafR because it allows users to fluidly interact with their experiment following tentative library identifications [i.e. after the m/z spectra have been matched against an installed chemical fragmentation database (e.g. NIST)]. Use of uafR will allow larger datasets to be collected and systematically interpreted quickly. Furthermore, the functions of uafR could allow backlogs of previously collected and annotated data to be processed by new personnel or students as they are being trained. This is critical as we enter the era of exposomics, metabolomics, volatilomes, and landscape level, high-throughput chemotyping. This package was developed to advance collective understanding of chemical data and is applicable to any research that benefits from GC -MS analysis. It can be downloaded for free along with sample datasets from Github at github.org/castratton/uafR or installed directly from R or RStudio using the developer tools: 'devtools::install_github("castratton/uafR")'. [ABSTRACT FROM AUTHOR]

Eriophyid mites, minute arachnids within the family Eriophyidae, pose significant threats to fruit crops globally, leading to substantial economic losses in agriculture. This comprehensive review aims to elucidate the intricate biology, ecology, molecular aspects, and innovative control strategies of these pervasive pests. Eriophyid mites exhibit a complex life cycle and reproductive strategy, with their habitat preferences and distribution heavily influenced by environmental factors and host-plant interactions. Advances in molecular biology have provided more profound insights into their genetics and interactions at the molecular level, revealing crucial information for developing targeted pest management strategies. Control strategies for eriophyid mites encompass chemical methods, such as applying acaricides and understanding resistance mechanisms, as well as biological control using natural predators and parasitoids. Cultural and physical control methods, including crop rotation and mechanical removal, play vital roles in integrated pest management (IPM). Emerging approaches like RNA interference (RNAi) and semiochemical-based controls offer promising alternatives for sustainable pest management. This review underscores the importance of a multifaceted approach to effectively manage eriophyid mite infestations, integrating traditional and novel strategies. Future research should focus on overcoming current challenges, enhancing the efficacy of control methods, and further exploring the molecular mechanisms underlying mite-plant interactions. [ABSTRACT FROM AUTHOR]

Closely-related plant groups with distinct microbiomes, chemistries and ecological characteristics represent tractable models to explore mechanisms shaping species spread, competitive dynamics and community assembly at the interface of native and introduced ranges. We investigated phyllosphere microbial communities, volatile organic compound (VOC) compositions, and potential interactions among introduced S. trilobata, native S. calendulacea and their hybrid in South China. S. trilobata exhibited higher α diversity but significantly different community composition compared to the native and hybrid groups. However, S. calendulacea and the hybrid shared certain microbial taxa, suggesting potential gene flow or co-existence. The potent antimicrobial VOC profile of S. trilobata, including unique compounds like p-cymene (13.33%), likely contributes to its invasion success. The hybrid's intermediate microbial and VOC profiles suggest possible consequences for species distribution, genetic exchange, and community assembly in heterogeneous environments. This hybrid deserves further study as both an opportunity for and threat to diversity maintenance. These differentiating yet connected plant groups provide insight into ecological and evolutionary dynamics shaping microbiome structure, species co-occurrence and competitive outcomes during biological exchange and habitat transformation. An interdisciplinary approach combining chemical and microbial ecology may reveal mechanisms underlying community stability and change, informing management of species spread in a globalized world. [ABSTRACT FROM AUTHOR]

Black apples are the result of late-stage microbial decomposition after falling to the ground. This phenomenon is highly comparable from year to year, with the filamentous fungus Monilinia fructigena most commonly being the first invader, followed by Penicillium expansum. Motivated by the fact that only little chemistry has been reported from apple microbiomes, we set out to investigate the chemical diversity and potential ecological roles of secondary metabolites (SMs) in a total of 38 black apples. Metabolomics analyses were conducted on either whole apples or small excisions of fungal biomass derived from black apples. Annotation of fungal SMs in black apple extracts was aided by the cultivation of 15 recently isolated fungal strains on 9 different substrates in a One Strain Many Compounds (OSMAC) approach, leading to the identification of 3,319 unique chemical features. Only 6.4% were attributable to known compounds based on analysis of high-performance liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS/MS) data using spectral library matching tools. Of the 1,606 features detected in the black apple extracts, 32% could be assigned as fungal-derived, due to their presence in the OSMAC-based training data set. Notably, the detection of several antifungal compounds indicates the importance of such compounds for the invasion of and control of other microbial competitors on apples. In conclusion, the diversity and abundance of microbial SMs on black apples were found to be much higher than that typically observed for other environmental microbiomes. Detection of SMs known to be produced by the six fungal species tested also highlights a succession of fungal growth following the initial invader M. fructigena. [ABSTRACT FROM AUTHOR]

Main conclusion: One of seven Solanum taxa studied displayed associations between pollen presence and floral scent composition and volume, suggesting buzz-pollinated plants rarely use scent as an honest cue for foraging pollinators. Floral scent influences the recruitment, learning, and behaviour of floral visitors. Variation in floral scent can provide information on the amount of reward available or whether a flower has been visited recently and may be particularly important in species with visually concealed rewards. In many buzz-pollinated flowers, tubular anthers opening via small apical pores (poricidal anthers) visually conceal pollen and appear similar regardless of pollen quantity within the anther. We investigated whether pollen removal changes floral scent composition and emission rate in seven taxa of buzz-pollinated Solanum (Solanaceae). We found that pollen removal reduced both the overall emission of floral scent and the emission of specific compounds (linalool and farnesol) in S. lumholtzianum. Our findings suggest that in six out of seven buzz-pollinated taxa studied here, floral scent could not be used as a signal by visitors as it does not contain information on pollen availability. [ABSTRACT FROM AUTHOR]

Brain evolution has primarily been studied at the macroscopic level by comparing the relative size of homologous brain centers between species. How neuronal circuits change at the cellular level over evolutionary time remains largely unanswered. Here, using a phylogenetically informed framework, we compare the olfactory circuits of three closely related Drosophila species that differ in their chemical ecology: the generalists Drosophila melanogaster and Drosophila simulans and Drosophila sechellia that specializes on ripe noni fruit. We examine a central part of the olfactory circuit that, to our knowledge, has not been investigated in these species—the connections between projection neurons and the Kenyon cells of the mushroom body—and identify species-specific connectivity patterns. We found that neurons encoding food odors connect more frequently with Kenyon cells, giving rise to species-specific biases in connectivity. These species-specific connectivity differences reflect two distinct neuronal phenotypes: in the number of projection neurons or in the number of presynaptic boutons formed by individual projection neurons. Finally, behavioral analyses suggest that such increased connectivity enhances learning performance in an associative task. Our study shows how fine-grained aspects of connectivity architecture in an associative brain center can change during evolution to reflect the chemical ecology of a species. Brain evolution at the cellular level is understudied. Here, the authors compare olfactory circuits from three Drosophila species, finding species-specific connectivity patterns associated with food odours and suggesting that more connectivity may be related to learning performance. [ABSTRACT FROM AUTHOR]

Fruit fly pests (Diptera: Tephritidae) are a serious problem for fruit production and for local and international trade. Biological control is increasingly included as a pest control tool within integrated pest management (IPM) programmes, seeking to reduce pesticides and improve fruit quality. Ceratitis capitata Wiedemann, the Mediterranean fruit fly (medfly), is probably the most damaging fruit fly pest, with a global distribution and more than 200 host species. The solitary larval endoparasitoid Diachasmimorpha longicaudata Ashmead (Hymenoptera: Braconidae) is a biocontrol agent widely used against Tephritidae fruit fly pests. Previous studies showed that female wasps locate host larvae using visual, mechanical, and chemical cues. Here, we investigated the chemical basis of female parasitoid attraction to cues that guide D. longicaudata to the host, and thus unveil volatile organic compounds that might be used in IPM programmes. Female orientation to chemical cues was tested in a Y‐tube olfactometer, where attraction to C. capitata‐infested oranges, oranges with residues of larval activity, oranges infected with a green mould, and overripe oranges was confirmed. Volatiles from all these types of fruit were collected and used in gas chromatography‐electroantennographic detection (GC‐EAD) and GC‐mass spectrometry (MS) analyses. These studies allowed us to identify six candidate compounds that were present in all treated oranges but not in the control fruit (ripe and uninfested oranges): D‐limonene, acetophenone, linalool, nonanal, decanal, and eugenol. Electroantennography (EAG) showed that acetophenone, nonanal, and decanal triggered dose‐dependent responses, suggesting a relevant role in the process of host finding. Although responses to D‐limonene, linalool, and eugenol were independent of the dose, they could be involved in host location in areas with high probability of host presence. The fact that these six compounds are shared by the four behaviourally attractive sources opens new possibilities for the development of novel tools to improve biocontrol programmes. [ABSTRACT FROM AUTHOR]

This special issue comprises papers presented at the 7th International Entomophagous Insects Conference (IEIC7), in Buenos Aires, Argentina, in 2023. Entomophagous insects, which prey on or parasitize other insects, play a pivotal role in ecosystems and are widely utilized as biocontrol agents. This special issue includes two review articles and nine research papers covering diverse subjects such as ecology, physiology, behavior, genetics, chemical ecology, and biological control, which reflects the diversity of topics presented and discussed during the conference. [ABSTRACT FROM AUTHOR]

Plankton parasites such as viruses, bacteria, fungi, and unicellular eukaryotes are associated symbionts colonizing algal groups in aquatic ecosystems. They occur within a network of microbe–microbe interactions in which they parasitize phytoplankton and seaweeds, i.e., primary producers generating organic carbon and forming the basis of marine food webs. These parasites use algae as a source of nutrients and reproduce at the expense of their host, causing infectious symptoms leading to disease and death. Plankton parasites can reduce the algal populations, and the infection of one specific species may, in turn, favor the development of another, influencing the seasonal succession of algal blooms in oceans, seas, and lakes. Many parasites have free-living stages that zooplankton graze upon, representing a significant trophic link in food webs. The biology and life cycle of plankton parasites are well investigated in marine and freshwater algal hosts. Still, the chemical signaling mediating these microbial interactions and the effect of co-occurring symbionts remain underexplored. This review focuses on the diversity of plankton parasites infecting algae, with a particular emphasis on unicellular eukaryotes. The ecological role of plankton parasites, the mechanisms regulating cellular infection and host resistance, and the interplay of alga-parasite interactions with coexisting microorganisms are discussed. [ABSTRACT FROM AUTHOR]

The agave weevil Scyphophorus acupunctatus is a polyphagous pest of agave, yucca and related taxa. Although its many host species differ in their mortality rates, little is known about the factors involved in host selection by the weevil and the defensive response of the infested plants. We compared the suitability of Agave americana subsp. americana, A. americana var. franzosini and A. oteroi as a food source for adult individuals of S. acupunctatus. Feeding rates on leaf samples of the selected taxa were measured under laboratory conditions. The amount of the flavonoids flavone and kaempferol in the leaves was also quantified. The observed consumption rates were significantly lower for A. americana var. franzosini, but only for measurements made on a fresh weight basis and not when consumption was adjusted to leaf dry weight. The leaves of the three agave taxa did not differ in the contents of the two selected flavonoids. We conclude that the three agave taxa are equally suitable as a food source for the weevil, but the observed differences in the consumption of fresh material provides evidence that agaves can differ in the amount of damage caused by the feeding activities of S. acupunctatus. [ABSTRACT FROM AUTHOR]

Actinomycetes are a phylogenetically diverse bacterial group which are widely distributed across terrestrial and aquatic ecosystems. Within this order, the genus Pseudonocardia and their specialised metabolites have been the focus of previous ecological studies due to their antagonistic interactions with other microorganisms and their mutualistic interactions with insects. However, the chemical ecology of free‐living Pseudonocardia remains understudied. This study applies a multi‐omics approach to investigate the chemical ecology of free‐living actinomycetes from the genus Pseudonocardia. In a comparative genomics analysis, it was observed that the biosynthetic gene cluster family distribution was influenced mainly by phylogenetic distance rather than the geographic or ecological origin of strains. This finding was also observed in the mass spectrometry‐based metabolomic profiles of nine Pseudonocardia species isolated from marine sediments and two terrestrial species. Antagonist interactions between these 11 species were examined, and matrix‐assisted laser desorption/ionisation‐mass spectrometry imaging was used to examine in situ chemical interactions between the Southern Ocean strains and their phylogenetically close relatives. Overall, it was demonstrated that phylogeny was the main predictor of antagonistic interactions among free‐living Pseudonocardia. Moreover, two features at m/z 441.15 and m/z 332.20 were identified as metabolites related to these interspecies interactions. [ABSTRACT FROM AUTHOR]

Triatomines are haematophagous insects, some species are vectors of Trypanosoma cruzi, the aetiological agent of Chagas disease. The main strategy for interrupting T. cruzi transmission is to avoid contact of the vector populations with humans. Volatiles from commercial essential oils are excellent candidates to serve as repellents of kissing bugs. We used an exposure device to assess the repellence effect of eight commercial essential oils on Triatoma pallidipennis. The most effective oils were blended and evaluated against T. infestans, T. pallidipennis and Rhodnius prolixus. The blend was also evaluated on parasitised T. pallidipennis. Data were compared with the commercial repellent NN‐diethyl‐3‐methylbenzamide. We recorded the time the insects spent in the proximity of the host and determined if any of the evaluated oils served as kissing bug repellent. We found commercial essential oils and a blend that significantly reduced the time spent in the proximity of the host. The blend was effective for use by human males and females, repelling infected and non‐infected insects. The study of essential oils as repellents of blood‐sucking disease‐vector insects could shed light on the development of new control strategies. [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]

Simple Summary: In our study, we explored ways to effectively trap invasive ambrosia beetles, which pose significant threats to trees and forests. We focused on comparing two types of bait—pure ethanol and denatured ethanol—to attract these pests in different environments like tree nurseries and orchards. We found that traps using pure ethanol captured more Xylosandrus germanus beetles compared to those with denatured ethanol. Our findings suggest that using pure ethanol could be more effective for monitoring certain ambrosia beetle species. This research contributes to better pest management strategies, helping protect trees from invasive pests, ultimately benefiting society by safeguarding ecosystems and agricultural productivity. Ambrosia beetles, particularly invasive species within the tribe Xyleborini, such as Xylosandrus germanus (Blandford, 1894), pose significant threats to various ecosystems and managed habitats worldwide. Monitoring these invaders is vital for effective pest management, typically accomplished through ethanol-baited traps. We compared trap efficacy using denatured ethanol versus absolute ethanol in orchards, tree nurseries, and lumber yards in northeastern Ohio, USA, finding that absolute ethanol traps captured significantly more X. germanus. Analysis revealed acetone, ethanol, and methyl isobutyl ketone in the denatured ethanol, likely impacting trap efficacy. Our study underscores the importance of using pure denatured ethanol without acetone for effective monitoring, especially for X. germanus. Exotic xyleborines dominated trap captures across various habitats, emphasizing the need for tailored pest management strategies. Further research is warranted to explore the chemical ecology of ambrosia beetles and the influence of ethanol impurities on trap effectiveness. [ABSTRACT FROM AUTHOR]

Ash dieback, caused by the fungal pathogen Hymenoscyphus fraxineus (Helotiales, Ascomycota), is threatening the existence of the European ash, Fraxineus excelsior. During our search for biological control agents for this devastating disease, endophytic fungi were isolated from healthy plant tissues and co-cultivated with H. fraxineus to assess their antagonistic potential. Among the strains screened, Penicillium cf. manginii DSM 104493 most strongly inhibited the pathogen. Initially, DSM 104493 showed promise in planta as a biocontrol agent. Inoculation of DSM 104493 into axenically cultured ash seedlings greatly decreased the development of disease symptoms in seedlings infected with H. fraxineus. The fungus was thus cultivated on a larger scale in order to obtain sufficient material to identify active metabolites that accounted for the antibiosis observed in dual culture. We isolated PF1140 (1) and identified it as the main active compound in the course of a bioassay-guided isolation strategy. Furthermore, its derivative 2, the mycotoxin citreoviridin (3), three tetramic acids of the vancouverone type (4-6), and penidiamide (7) were isolated by preparative chromatography. The structures were elucidated mainly by NMR spectroscopy and high-resolution mass spectrometry (HRMS), of which compounds 2 and 6 represent novel natural products. Of the compounds tested, not only PF1140 (1) strongly inhibited H. fraxineus in an agar diffusion assay but also showed phytotoxic effects in a leaf puncture assay. Unfortunately, both the latent virulent attributes of DSM 104493 observed subsequent to these experiments in planta and the production of mycotoxins exclude strain Penicillium cf. manginii DSM 104493 from further development as a safe biocontrol agent. [ABSTRACT FROM AUTHOR]

Plants have developed chemical defence strategies which can either be triggered in response to herbivory or by the exogenous application of phytohormones, such as methyl jasmonate (MeJa). Tuta absoluta is the main pest associated with tomatoes worldwide. However, studies on the impact of plant hormones on this system are still scarce. This study aimed to evaluate the chemotactic responses and oviposition of T. absoluta towards tomato plants induced by MeJa and herbivory injuries. We conducted dual‐choice olfactometry bioassays evaluating the response of virgin T. absoluta males and females exposed to plants with conspecifics (eggs and caterpillars) and sprayed with MeJa (0.5 mM) at 24, 48, 72 and 96 h after the treatments. We also evaluated the oviposition preference of mated T. absoluta with the chance of choosing plants exposed to water, herbivory and three phytohormone concentrations (0.1, 0.5 and 2.5 mM). The males were mostly responsive to plants with conspecifics, while the females preferred intact plants over those sprayed with MeJa and with the presence of eggs. Furthermore, plants with MeJa (0.5 and 2.5 mM) and injured by conspecifics had less oviposition by T. absoluta. The results show that spraying MeJa on tomato plants is a potential tool for managing and controlling the tomato moth. [ABSTRACT FROM AUTHOR]

Along with climate change, or by transportation of agricultural products, such as fruits and ornamental plants, their alien insect pests have also started to appear in Hungary. Although these pest species are sometimes sparsely studied, their biology and interactions with their host plants provide key information for monitoring their spread and identifying their vulnerable points, targets for developing methods preventing their overpopulation. In this review article we have collected data on newly emerged moth species recently found in Hungary that might threaten plantations in Hungary in the near future. [ABSTRACT FROM AUTHOR]

Sexual selection is often studied with a focus on female mate choice, wherein females evaluate male signals to select an optimal mate. However, in some systems, males should also make careful decisions about the females they choose to court, particularly when faced with the risk of precopulatory sexual cannibalism. Here, we explore the idea that male jumping spiders (Habronattus brunneus) may mitigate this risk by responding to female cues probably associated with female aggression and/or receptivity. We tested mature male spiders’ ability to discriminate between substrate-borne cues (i.e. silk and excreta) produced by conspecific females of different ages and mating statuses. We found that males spent more time exploring cues produced by mature, non-mated females compared with either immature females or mated females. Heightened interest in cues produced by females that are sexually mature but not yet mated may allow males to reduce cannibalism risk, reduce wasted courtship effort and increase their reproductive success. The use of chemical and/or tactile cues in jumping spider courtship behaviour has been vastly understudied compared with the ways they use vision; this study provides the groundwork for understanding how these sensory modalities interact.

Eriophyid mites, minute arachnids within the family Eriophyidae, pose significant threats to fruit crops globally, leading to substantial economic losses in agriculture. This comprehensive review aims to elucidate the intricate biology, ecology, molecular aspects, and innovative control strategies of these pervasive pests. Eriophyid mites exhibit a complex life cycle and reproductive strategy, with their habitat preferences and distribution heavily influenced by environmental factors and host-plant interactions. Advances in molecular biology have provided more profound insights into their genetics and interactions at the molecular level, revealing crucial information for developing targeted pest management strategies. Control strategies for eriophyid mites encompass chemical methods, such as applying acaricides and understanding resistance mechanisms, as well as biological control using natural predators and parasitoids. Cultural and physical control methods, including crop rotation and mechanical removal, play vital roles in integrated pest management (IPM). Emerging approaches like RNA interference (RNAi) and semiochemical-based controls offer promising alternatives for sustainable pest management. This review underscores the importance of a multifaceted approach to effectively manage eriophyid mite infestations, integrating traditional and novel strategies. Future research should focus on overcoming current challenges, enhancing the efficacy of control methods, and further exploring the molecular mechanisms underlying mite-plant interactions