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The view of insects and their microbiota as a holobiont is increasingly relevant as globalization and climate change aids the spread of pests to new areas. Examples of such pests include bark, ambrosia, and woodborer beetles (BAWBBs hereafter) that are important natural components of forest ecosystem processes, but may also cause substantial damage in native and invasive ranges. Microbiota has been shown to perform various functions for these beetles, but we are only beginning to reveal the complex chemically mediated interactions among the beetle, the host tree and their microbiota. In this review we a) summarize current knowledge about the influence of beetle ecology in the formation of the holobiont, b) how microbial compounds may function as beetle semiochemicals, and/or contribute to nutrient acquisition, defence, and maintenance of the holobiont, c) the influence of external factors that affect the holobiont, and d) pinpoint open questions and suggest potential methods needing attention in order to utilize this knowledge in of management of invasive or outbreaking BAWBBs. [ABSTRACT FROM AUTHOR]

Floral mimics deceive their pollinators by developing visual and olfactory resemblance to various models. We report a flower that exhibits phenotypes like aerial litter and deceives an aerial litter specialist beetle to achieve pollination. We assessed the floral phenology and the effective pollinators of an Australian understorey treelet, Meiogyne heteropetala (Annonaceae). The similarities of morphology, colour and odour between the flowers and co‐occurring aerial litter were investigated. The terpene synthase involved in floral scent emission was identified by expression patterns and product profile. The behavioural responses of the pollinator to various odours were assessed using bioassays. The erotylid beetle Loberus sharpi is the most likely effective pollinator because it was the only pollen‐laden visitor during the pistillate phase. Loberus sharpi was exclusively found in aerial litter and M. heteropetala flowers. The flowers offer an honest shelter reward. The beetle also oviposits there, but most larvae eventually perished as the petals dropped onto the forest floor. The morphology and spectral reflectance of the flowers overlap with aerial litter. The floral scent was dominated by monoterpenes, especially 1,8‐cineole. The cineole synthase MhCINS was the only highly expressed floral terpene synthase and possessed a highly similar product profile to the floral scent composition. The volatile composition of M. heteropetala flowers is distinct from other congeners and highly similar to aerial litter, indicating advergence to aerial litter. Visual and odour resemblance, coupled with low larval survivorship, provides evidence that the beetles were deceived into pollinating the flowers. Behavioural experiments showed that the pollinator was attracted to both aerial litter and M. heteropetala flowers. The beetles were also attracted to 1,8‐cineole and synthetic mixes of floral odour and MhCINS products. The beetles were unable to distinguish floral scent from MhCINS products nor from 1,8‐cineole, suggesting MhCINS alone sufficed to attract the pollinator olfactorily. The beetles, however, preferred aerial litter over flowers. The beetles likely categorised the flower as a general, but not the most preferred, brood substrate. Synthesis. This study reports the first case of floral mimicry of aerial litter and characterises the biochemical process responsible for olfactory mimicry. [ABSTRACT FROM AUTHOR]

The spotted‐wing drosophila, Drosophila suzukii and the cosmopolitan vinegar fly D. melanogaster feed on soft fruit and berries and widely overlap in geographic range. The presence of D. melanogaster reduces egg‐laying in D. suzukii, possibly because D. melanogaster outcompetes D. suzukii larvae feeding in the same fruit substrate. Flies use pheromones to communicate for mating, but pheromones also serve a role in reproductive isolation between related species. We asked whether a D. melanogaster pheromone also modulates oviposition behaviour in D. suzukii. A dual‐choice oviposition assay confirms that D. suzukii lays fewer eggs on blueberries exposed to D. melanogaster flies and further shows that female flies have a stronger effect than male flies. This was corroborated by treating berries with synthetic pheromones. Avoidance of D. suzukii oviposition is mediated by the female D. melanogaster pheromone (Z)‐4‐undecenal (Z4‐11Al). Significantly fewer eggs were laid on berries treated with synthetic Z4‐11Al. In comparison, the male pheromone (Z)‐11‐octadecenyl acetate (cVA) had no effect on D. suzukii oviposition. Z4‐11Al is a highly volatile compound that is perceived via olfaction and it is accordingly behaviourally active at a distance from the source. D. suzukii is known to engage in mutual niche construction with the yeast Hanseniaspora uvarum, which strongly attracts flies. Adding Z4‐11Al to fermenting H. uvarum significantly decreased D. suzukii flight attraction in a laboratory wind tunnel and a field trapping assay. That a D. melanogaster pheromone regulates oviposition in D. suzukii demonstrates that heterospecific pheromone communication contributes to reproductive isolation and resource partitioning in cognate species. Stimulo‐deterrent diversion or push‐pull methods, building on combined use of attractant and deterrent compounds, have shown promise for control of D. suzukii. A pheromone that specifically reduces D. suzukii attraction and oviposition adds to the toolbox for D. suzukii integrated management. [ABSTRACT FROM AUTHOR]

Pinus sylvestris trees are known to efficiently defend themselves against eggs of the herbivorous sawfly Diprion pini. Their direct defense against eggs is primable by prior exposure to the sex pheromones of this species and their indirect defense involves attraction of egg parasitoids by egg-induced pine needle odor. But it is unknown whether exposure of pine to D. pini sex pheromones also affects pine indirect defense against sawfly eggs. In this study, we investigated the influence of exposure of P. sylvestris trees to the sex pheromones of D. pini on indirect defense mediated by egg parasitoids. Behavioral assays with Closterocerus ruforum, a key parasitoid of sawfly eggs, revealed no significant attraction to odor from egg-free pines pre-exposed to pheromones. Chemical analyses of odor from egg-free pines showed no pheromone-induced change in the emission rates of the known key terpenoids promoting parasitoid attraction. Further comparative analyses of odor from egg-laden pines pre-exposed to the sex pheromones and of odor from egg-laden pines unexposed to pheromones neither revealed significant differences in the emission rates of terpenoids relevant for parasitoid attraction. The results suggest that a pheromone-induced or pheromone-primed, egg-induced pine indirect defense seems to be redundant in addition to the known pheromone-primable pine direct defense against the eggs and the known egg-inducible indirect defense. [ABSTRACT FROM AUTHOR]

Semiochemicals left by predators in their foraging area can be utilised by prey to avoid predation. The range of predators' chemical cues with contrasting degradation rates might provide information of different quality, potentially allowing prey to differentiate between the immediate and the longer-term presence of predators in a location. So far, knowledge about the roles of volatile versus stable chemical cues in informing predation risk is limited. We here seek to disentangle the role of ephemeral trail pheromones compared to persistent cuticular hydrocarbons of ants (predators) on the antipredator behaviour of juvenile spiders (prey), with the expectation that volatile semiochemicals induce avoidance behaviour in spiders at a higher rate compared to stable cues. We allowed the spiders to choose between sites with and without ant cues separately for volatile trail pheromones and stable hydrocarbons. Unexpectedly, spiders avoided the presence of persistent cuticular hydrocarbons more clearly than the highly volatile trail pheromone. This underscores the widespread impact of these stable cues on the avoidance behaviour of potential intraguild prey. The response to trail pheromones was unclear, possibly because spiders always encounter these cues simultaneously with visual and vibratory cues from ants; hence, trail pheromones may not contain any additional information, hindering the evolution of the ability to detect them. [ABSTRACT FROM AUTHOR]

Stable flies, Stomoxys calcitrans (L.), are blood-feeding ectoparasites of cattle. Host-seeking stable flies respond to various cattle host cues, but a potential role of cattle breath gases [carbon dioxide (CO2), methane (CH4)] and cattle breath volatiles (acetone, isoprene, 2-butanone, 2-propanol, propionic acid, 3-methyl butyric acid, phenol), alone or in combination, on host-seeking behavior of stable flies has not yet been comprehensively investigated. In laboratory and greenhouse experiments, we tested the hypotheses that (1) CO2 and CH4 interactively attract stable flies, (2) CO2 'gates' attraction of stable flies to CH4, and (3) breath volatiles on their own, or in combination with both CO2 and CH4, attract stable flies. In Y-tube olfactometer experiments, the blend of CH4 (0.5%) and CO2 (1%) in breathing air ('b-air') attracted significantly more female flies than CH4, or CO2, in b-air. The flies' responses to CH4 were contingent upon their prior or concurrent exposure to CO2. In two-choice experiments in a large greenhouse compartment, significantly more flies landed on the host-look-alike barrel that disseminated a blend of CO2 and CH4 in b-air (CO2/CH4/b-air) than on the barrel disseminating either b-air or CO2. Moreover, significantly more flies landed on the barrel that disseminated synthetic breath volatiles (SBVs) than on the barrel disseminating b-air. The blend of CO2/CH4/b-air and SBVs elicited more fly landings on barrels than CO2/CH4/b-air but not than SBVs. SBVs, possibly combined with both CH4 and CO2, could be developed as a lure to enhance trap captures of stable flies in livestock production facilities. [ABSTRACT FROM AUTHOR]

Fast and effective monitoring and surveillance techniques are crucial for the swift implementation of control methods to prevent the spread of Huanglongbing, a devastating citrus disease, and its invasive psyllid vector, Asian citrus psyllid, Diaphorina citri, into South Africa, as well as to control the native vector, African citrus triozid, Trioza erytreae. Monitoring for citrus psyllid pests can be improved by using semiochemical odorants to augment already visually attractive yellow sticky traps. However, environmental variables such as temperature and humidity could influence odorant release rates. Five field cages were used to test the ability of a selection of odorants to improve yellow sticky trap efficacy in capturing citrus psyllids. Environmental effects on odorant loss from the dispensers were also investigated. The odorants that most improved yellow sticky trap captures in field cages were then tested under open field conditions alongside lower concentrations of those same lures. Gas chromatography-mass spectrometry was used to calculate odorant release rates as well as to determine if any contamination occurred under field conditions. None of the odorants under field cage or field conditions significantly improved psyllid capture on yellow sticky traps. Temperature influenced odorant loss, and release rate from polyethylene bulbs decreased over time. Based on these results, the use of unbaited yellow sticky traps seems to be the most effective method for monitoring of Huanglongbing vectors. [ABSTRACT FROM AUTHOR]

Cetoniidae (Coleoptera), known as flower and fruit beetles, form a diverse group, feed on nectar, pollen, plant exudates, and are highly attracted to fermented fruits. To evaluate their diversity in natural and agricultural areas, traps baited with fermented fruits are used. The objective of this study was to compare the effectiveness of various types of fruit used as bait, with or without the addition of sugarcane juice to accelerate fruit fermentation, on the assessment of Cetoniidae diversity in the Brazilian Cerrado. The study was conducted in two conservation units in Brasília (DF, Brazil). Two experiments were conducted, the first aiming to select the most attractive fruits (banana, pineapple, mango, grape, or cagaita), and the second to verify whether there is interference of sugarcane juice in the fruit fermentation process and, consequently, in the attractiveness to Cetoniidae. The chemical profiles of the types of bait were evaluated by identifying and quantifying the main volatile organic compounds released by the fruit traps. Insect collections were conducted weekly using fruit‐baited traps for 1 month, without interruption. We found that the diversity estimate of Cetoniidae was higher for banana‐based baits relative to grape and cagaita fruit, but not relative to pineapple, mango, and sugarcane juice. Additionally, no increase in attractiveness was observed with the addition of sugarcane juice to banana, pineapple, and mango bait. Most compounds in the fruit extracts belong to alcohol, ester, and terpene functional groups. Our results suggest that banana, pineapple, mango, and sugarcane juice, used alone, may be used for Cetoniidae diversity studies, and that banana bait seems to be the most suitable for Cetoniidae collection in the Cerrado, because it enables the collection of a high diversity of species and also of species considered rare. [ABSTRACT FROM AUTHOR]

Thrips, Frankliniella intonsa, is a highly polyphagous pest with a worldwide distribution. F. intonsa‐infested sunflower seeds show marked visual damage. The study findings revealed that significantly more F. intonsa infested confection sunflower compared to oilseed sunflower, via olfactometer bioassay studies, we found that compared with the flower and pollen of oilseed sunflowers, those of confection sunflowers attract F. intonsa. Considering this discrepancy in the preference of F. intonsa on oilseed and confection sunflowers, the volatiles of the flower and pollens of two sunflowers were analysed by gas chromatography‐mass spectroscopy. The behavioural responses of F. intonsa were assessed for these compounds using Y‐tube bioassays. Geranyl bromide, a unique volatile component of oilseed sunflowers, induced an assertive approach‐avoidance behaviour in F. intonsa, whereas the unique component ethyl isovalerate in confection sunflowers attracted F. intonsa. F. intonsa adults demonstrated significant attraction to the blends of confection sunflowers. Furthermore, field verification revealed that intercropping confection and oilseed sunflowers could effectively control F. intonsa. The study provided insights into the chemical cues used by F. intonsa in locating hosts. Therefore, oilseed sunflowers can be used as repellent plants to prevent F. intonsa invasion. Summary Statement: The damage to sunflower seeds is caused by Frankliniella intonsa. A previous study found that the seed damage rate of oilseed sunflower varieties was lower than that of confection sunflower varieties. Understanding the underlying reason behind this distinction can help us understand the behaviour of F. intonsa, thereby aiding their control. Our research shows that the attraction of sunflower volatiles to F. intonsa is the root cause of the difference in F. intonsa population. Geranyl bromide, a unique volatile component of oilseed sunflowers, induces an assertive approach‐avoidance behaviour in F. intonsa, whereas the unique component ethyl isovalerate in confection sunflowers attracts F. intonsa. F. intonsa adults demonstrated significant attraction to the blends of confection sunflowers. Furthermore, field verification revealed that intercropping confection and oilseed sunflowers could effectively control F. intonsa. The study provided insights into the chemical cues used by F. intonsa in locating hosts. Therefore, oilseed sunflowers can be used as repellent plants to prevent F. intonsa invasion. [ABSTRACT FROM AUTHOR]

Simple Summary: Proholopterus chilensis (Cerambycidae: Cerambycinae) is a native species and an important damage agent in the Nothofagaceae forests of southern Chile, significantly affecting timber production in some areas, especially production of Nothofagus obliqua, with no sanitary management measures currently available. Therefore, the present research determined the predisposing factors for male–female sex approaches and identified, for the first time, some compounds that appear to mediate sexual behaviors that could be used to develop specific, safe, and effective control strategies. Interestingly, the chemical communication for mating purposes in P. chilensis preliminarily seems to include both possible "volatile or airborne" pheromones (eventually long-range ones) and short-range pheromonal compounds produced only by females, something, as far as we know, unique in Cerambycinae. During the spring–summer seasons between 2019 and 2023, in the localities of Maquehue (La Araucanía Region) and Llifén (Los Ríos Region), we collected 262 virgin Proholopterus chilensis (1 female/2.3 males) specimens emerging from the live trunks of N. obliqua trees, an atypical sex ratio in Cerambycidae, suggesting high male competition for females. Virgin specimens of both sexes were individually placed in panel traps in the field, capturing only males (n = 184) over the field study seasons and only in traps baited with females. This fact preliminarily suggests the P. chilensis females emit possible "volatile or airborne" pheromones (eventually being a long-range sex pheromone), something unusual in Cerambycinae, the subfamily to which it currently belongs, although the taxonomic status of the species is under debate. In Llifén and Santiago (Metropolitan Region), behavioral observations were conducted, which allowed us to define the conditions necessary for male–female encounters that were replicated when carrying out volatile captures (Head Space Dynamic = HSD) and collections of compounds from terminalias excised from females. In field trials, virgin females less than ten days old were more attractive than older ones and attracted males during the night, i.e., between 23:00 and 5:00 AM, when the ambient temperature exceeded 11.6 °C. The aeration of females under the conditions described above and subsequent analysis of extracts by GC-MS allowed the identification of compounds absent in males and the control, including two oxygenated sesquiterpenes, a nitrogenous compound (C20), and a long-chain hydrocarbon (C26). From the terminalia extracts, hentriacontane, heptacosane, and heneicosyl, heptacosyl and docosyl acetates were identified by GC-MS, and their roles are unknown in the development of short-distance sexual behaviors, but they could serve to mark a trail leading the male towards the female in the final stage of approach for courtship/mating. Thus, we proposed the hypothesis that P. chilensis females emit both a long-range and a trail-pheromone, which, if confirmed, would be a rare case in this family. The specific identity of the compounds obtained by HSD, as well as the activities of these chemicals and those obtained from the terminalias, should be evaluated in future behavioral studies, as well as regarding their potential to attract males under field conditions. The current document is the first report on volatiles obtained from aerations and compounds extracted from female terminalia in P. chilensis. [ABSTRACT FROM AUTHOR]

Simple Summary: The Canary Island palm, Phoenix canariensis H. Wildpret, is a resource of great economic and scenic value in the Canary Islands, whose natural palm groves are priority habitats and protected by law. The palms are being severely affected by a small weevil, Diocalandra frumenti, whose larvae burrow galleries in the leaves, causing their premature drying and collapse, especially in urban environments. This study focuses on developing an effective trap to capture D. frumenti, evaluating several factors such as type, design, colour, height, distance and location of the traps with respect to the palm trees to determine the most efficient configuration. The resulting trap, a green, uncovered Econex® moth trap (Sanidad Agrícola Econex S.L., Murcia, Spain) with ventilation holes and baited with sugar cane and water, proved to be effective in capturing D. frumenti. The combination of this trap with a D. frumenti-specific pheromone will provide a valuable tool for early detection in areas free of the pest, as well as for monitoring and mass trapping in affected areas. The results of this research will have a significant impact on the protection of the valuable natural palm groves of the islands, benefiting both the economy and the landscape of the Canary Islands. Diocalandra frumenti (Fabricius) (Coleoptera: Dryophthoridae) is a weevil present in the Canary Islands, affecting economically important palms such as Phoenix canariensis H. Wildpret and its hybrids, for which there were no trapping tools. The larvae cause the main damage by burrowing galleries in the rachis of the leaves, causing premature drying and collapse. To develop an effective trap, six trials were carried out to evaluate the effect of trap type, design, colour, height, distance and location of the trap in relation to the palm tree on D. frumenti captures. This study confirms that the Econex® trap, green in colour, without a cover and with two ventilation holes of 2.5 cm in diameter, diametrically opposite each other and at 1 cm from the top of the base of the trap, baited with sugar cane and water, and placed between the first and second ring of green leaves of the palm canopy, is efficient in capturing D. frumenti. These results establish a basis for future research focused on the development of a specific trapping system based on semiochemicals to serve as a tool for detection, monitoring and mass trapping of D. frumenti. [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]

Biological invasions are partly defined by their ability to spread rapidly within invaded regions, posing threats to biodiversity and local species assemblages. The painted bug, Bagrada hilaris (Hemiptera, Pentatomidae) (Burmeister, 1835), originally described as being from India, is an important pest worldwide, mainly due to the serious economic losses incurred and the large number of zones invaded. Since its initial detection in Chile in 2016, the invasive and destructive paint bug has started its invasion to the east and invaded new areas in South America. Without adequate control methods, the insect may threaten brassica crop production, resulting in yield losses greater than 70% in recently infested areas. The extraordinarily wide range of the B. hilaris invasion has necessitated studies describing its biology and ecology, as well as highlighting the urgent need for effective and long-term management techniques. Hence, thoroughly revising the data on this pest in new areas that have been invaded, as well as in the area of origin, is expected to enable the development of management programs. This review incorporates information on B. hilaris in South America, including the invasion, ecology, and potential management approaches, which may allow for efficient integrated pest management, mainly in Chile. Lastly, researchers are expected to break the bottlenecks of some key issues, offering valuable perspectives for identifying strategies that warrant additional research as potential biological control agents for B. hilaris in South America, utilizing either augmentative or conservation biological control approaches, as well as semiochemicals and cultural practices. [ABSTRACT FROM AUTHOR]

Conservation biological control (CBC) is a sustainable measure for ecological intensification in agriculture to establish and maintain robust natural enemy populations. CBC is contributing to integrated pest management with reduced use of pesticides and support of native biodiversity in agroecosystems. Despite rapidly expanding research on CBC during the last decades, its application in pest management at the farm level is very limited. Here, we tested a CBC strategy in a 5-year on-farm study at three locations in East Norway. This CBC strategy combined two tools to increase biological control of aphids in spring barley; 1-ATTRACT, the application of a volatile organic compound (VOC) attractant that increases lacewing egg laying, and 2-HABITAT, the maintenance of natural border vegetation. We found that the VOC attractants recruited natural enemies and guided them to the right place at the right time from the border vegetation into the cropping area to control the aphid population efficiently and reliably. The results also showed that the VOC attractants combined with periodical maintained natural border vegetation provided a higher lacewing activity and aphid suppression than with annual sown floral buffer strips. We found that maintained natural border vegetation supported by VOC attractants provided lacewing populations that controlled aphids up to 100 m into the cropping area. Without VOC attractants we recorded lacewing activity up to 50 m from the border into the cropping area if natural border vegetation was available, and up to 25 m if no border vegetation existed. The overall results demonstrated the feasibility of this CBC approach under Norwegian farming conditions leading to the successful adoption of this CBC-strategy by the farming community. [ABSTRACT FROM AUTHOR]

Chemical signals have an important role in the survival of many animals and are essential for the exploration of the resources available in their habitat. All phytophagous insects, including dipterans, use diverse chemical compounds released by plants as olfactory signals to locate their hosts. Spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is a generalist fly that uses numerous plants as hosts. In this study, we evaluated the attractiveness of extracts from six plants commonly used as ornamental and medicinal plants in the southern region of Mexico. When the flies were exposed to Piper auritum Kunth (Piperaceae) extract, we observed a stimulating‐attracting effect, especially on females, whereas the other five extracts showed no significant differences from their respective controls. In addition, gas chromatography coupled with mass spectrometry analysis of the P. auritum extract revealed 11 compounds, where safrole and methyl eugenol (ME) showed the highest concentrations of all the compounds found. ME has been shown to attract flies, mainly males of the genus Bactrocera. In this case, we found a stronger effect on female D. suzukii, indicating a potential effect of ME as a kairomone that mainly stimulates the attraction behavior of females. [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]

This work focuses on the profiling of semiochemicals (SCS) from Callosobruchus maculatus, Sitophilus oryzae and Tribolium castaneum by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS) technique. Totally, 6, 9 and 8 volatile compounds (VCS) were detected from C. maculatus, S. oryzae and T. castaneum, respectively. As a result of pherobase analysis and preference bioassay, stearic acid (C. maculatus); nonanal, lauric acid and stearic acid (S. oryzae); stearic acid (T. castaneum) were identified as new SCS that could be useful for integrated pest management (IPM) practices. [ABSTRACT FROM AUTHOR]

BACKGROUND: Whiteflies are major pests in agriculture, causing damage to crops and transmitting plant viruses. Using Volatile Organic Compounds (VOCs) as semiochemicals offers a sustainable approach for combating whiteflies. One such group of compounds, represented by β‐ionone, has been found to possess repellent/attractant properties. To further explore the behavioral effects of these compounds on whiteflies, we selected five natural ionone compounds and synthesized six novel analogues to examine the impact of structural variations on whitefly behavior. RESULTS: Our results demonstrated that β‐ionone and its analogues have a significant impact on the behavior of whiteflies. Among them, 0.01% pseudo ionone solution exhibited an attractant effect on whiteflies. Notably, the application of 1% β‐ionone and 0.1% β‐ionol solution demonstrated a notable repellent effect and oviposition deterrent effect on whitefly. We also found that the novel ionone analogue (±)1A exhibited a strong repellent effect. Both β‐ionol and compound (±)1A possess high logP values and low saturation vapor pressures, which contribute to enhanced lipophilicity, making them more likely to penetrate insect antennae and prolong their presence in the air. CONCLUSION: The newly discovered ionone analogue (±)1A and β‐ionol exhibit improved repellent effects, while pseudo ionone shows an attractant effect. These three compounds hold promising potential for development as novel biological control agents. Our work highlights the efficacy of VOCs as a protection method against whiteflies. These findings indicate that our new technology for a 'push–pull' control method of B. tabaci can offer a novel tool for integrated pest management (IPM). © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Emotions and behavior can be affected by social chemosignals from conspecifics. For instance, olfactory signals from stressed individuals induce stress-like physiological and synaptic changes in naïve partners. Direct stress also alters cognition, but the impact of socially transmitted stress on memory processes is currently unknown. Here we show that exposure to chemosignals produced by stressed individuals is sufficient to impair memory retrieval in unstressed male mice. This requires astrocyte control of information in the olfactory bulb mediated by mitochondria-associated CB1 receptors (mtCB1). Targeted genetic manipulations, in vivo Ca2+ imaging and behavioral analyses reveal that mtCB1-dependent control of mitochondrial Ca2+ dynamics is necessary to process olfactory information from stressed partners and to define their cognitive consequences. Thus, olfactory bulb astrocytes provide a link between social odors and their behavioral meaning. By focusing attention to potential dangers, social transmission of stress is key for animal survival. Here the authors show that CB1-dependent control of astrocyte mitochondria is necessary to assign cognitive value to odorants from stressed conspecifics. [ABSTRACT FROM AUTHOR]

Simple Summary: This study addresses global food security by highlighting the challenge of protecting food losses from insect damage. To find effective low-risk ways to manage these pests, we assessed the avoidance of the red flour beetle, a common pest in stored grains, to essential oils. Through various experiments in the laboratory, we investigated the beetles' behavioral response to different scented oils. While no definitive repellent was identified, this study sheds light on factors influencing insect behavior and the need for further research in behaviorally based management tactics such as avoidance. Ultimately, this work aims to develop strategies to protect stored grains, contributing to global food security efforts. Background: Food security is an increasingly pressing global issue, and by 2050, food production will not be sufficient to feed the growing population. Part of global food insecurity can be attributed to post-harvest losses, including quantity and quality losses caused by stored-product pests like insects. It is thus timely to find management strategies to mitigate these losses and counteract food insecurity. The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), a global stored-product pest with a wide range of food sources, was used in this study to assess repellency to a selection of essential oils. Methods: Multiple behaviorally relevant methods were used to determine the efficacy of the essential oils in assays to pinpoint the most promising repellents. Experiments were used to assess individual and group behaviors with or without airflow and examined the behavioral variation in distance moved and the time spent away from the oil. Results: It was found that exposure to essential oils and conditions of experimentation considerably influenced T. castaneum's behavioral response, but a clear candidate for repellency could not be chosen based on the collected data. Conclusions: Follow-up research is needed to pinpoint repellents for integrated pest management practices to protect grains from stored-product pests and to justify their use in and around commodities. [ABSTRACT FROM AUTHOR]

Regional variation in pheromone production and response has practical implications for the use of semiochemical lures to monitor and control bark beetle populations. We tested 4 lure formulations including 2 new formulations that reflect the pheromone production profiles of western and eastern populations of spruce beetles, Dendroctonus rufipennis Kirby (Coleoptera: Curculionidae), as well as 2 commercially available formulations (current Rocky Mountain lure and current Atlantic lure), in 2 locations in New Brunswick, Canada. In 2 separate years, the new eastern lure containing seudenol, MCOL, and spruce terpenes captured 4 times (2021) and 11 times (2022) more spruce beetles than the current Atlantic lure that consisted of frontalin, seudenol, and spruce terpenes. In 2021, we also captured more eastern larch beetles, Dendroctonus simplex LeConte (Coleoptera: Curculionidae), with the new eastern lure, whereas in 2022, we captured the most D. simplex with the current Atlantic lure, suggesting that more research is needed on D. simplex pheromone production and response across its range. The bark beetle predator, Thanasimus dubius (Fabr.; Coleoptera: Cleridae), did not respond well to the new eastern blend that lacks frontalin, suggesting that response to frontalin is important in finding prey and might be conserved in predator populations. The reduced trap catch of T. dubius to the enhanced lure is beneficial because it does not inhibit natural population control by removing predators from the community. Our study reveals an improved trap lure for eastern populations of spruce beetles and highlights gaps and research needs in bark beetle pheromone ecology. [ABSTRACT FROM AUTHOR]

The hibiscus bud weevil (HBW), Anthonomus testaceosquamosus Linell (Coleoptera: Curculionidae), is a significant threat to tropical hibiscus (Hibiscus rosa-sinensis) in Florida, USA, since its invasion in 2017. As a regulated pest in the state, early detection is crucial. Based on the success of pheromone-based monitoring programs for other weevil pests, such as the boll weevil, cranberry weevil, and pepper weevil, this study explores the potential use of these pheromone lures for early detection of HBW. To account for differences in efficacy based on trap color, height, and design, different pheromone lure sizes (4 mm, 10 mm, full-size), trap types (Yellow sticky trap, Japanese beetle trap, Boll weevil trap), and heights (0 m, 1.1 m) were also tested in this study. In laboratory assays, males and females exhibited higher attraction to full-size cranberry weevil lure discs than other lure size-type combinations. In semi-field trials, yellow sticky traps baited with cranberry weevil lures captured more weevils than Japanese beetle or boll weevil traps baited with cranberry weevil lures, while trap height did not influence HBW capture. In semi-field, 4-choice bioassays, yellow sticky traps baited with cranberry weevil lures captured more HBW compared to yellow sticky traps baited with pepper weevil, boll weevil, or unbaited traps. Further research is required to thoroughly evaluate the cranberry weevil lure's efficacy in capturing HBW. Our study suggests the potential for utilizing yellow sticky traps baited with lures for early HBW detection and highlights the importance of selecting the appropriate lure, trap type, and height for optimal efficacy. [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]

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]

Semiochemicals can be used to manipulate insect behaviour for sustainable pest management strategies, but their high volatility is a major issue for their practical implementation. Inclusion of these molecules within porous materials is a potential solution to this issue, as it can allow for a slower and more controlled release. In this work, we demonstrate that a series of Zr(IV) and Al(III) metal‐organic frameworks (MOFs) with channel‐type pores enable controlled release of three semiochemicals over 100 days by pore size design, with the uptake and rate of release highly dependent on the pore size. Insight from grand canonical Monte Carlo simulations indicates that this is due to weaker MOF‐guest interactions per guest molecule as the pore size increases. These MOFs are all stable post‐release and can be reloaded to show near‐identical re‐release profiles. These results provide valuable insight on the diffusion behaviour of volatile guests in MOFs, and for the further development of porous materials for sustainable agriculture applications. [ABSTRACT FROM AUTHOR]

Phyllocnistis citrella Stainton, commonly known as the citrus leafminer, threatens global citrus production. This study focuses on elucidating the population dynamics and spatial distribution of P. citrella in lemon orchards located in Northern Portugal. From May to December, using delta traps with sexual pheromones, the levels of the adult population were monitored, and aggregation indices were calculated. Five distinct density peaks are observed, with the highest recorded in late July to early August. Spatial distribution consistently indicated an aggregated pattern. However, temporal variation in distribution was observed on specific dates. According to our results, it is suggested deploying two or three traps per hectare during peak density periods. This study significantly advances our understanding of P. citrella dynamics, emphasizing the need to consider spatial and temporal patterns for effective pest management. The outcomes underscore the importance of further exploration into factors influencing distribution patterns to refine control strategies. These insights are crucial for devising targeted and efficient measures to mitigate the impact of P. citrella on citrus orchards globally. [ABSTRACT FROM AUTHOR]

Insect-plant interactions are shaped by the exchange of chemical cues called semiochemicals, which play a vital role in communication between organisms. Plants release a variety of volatile organic compounds in response to environmental cues, such as herbivore attacks. These compounds play a crucial role in mediating the interactions between plants and insects. This review provides an in-depth analysis of plant semiochemicals, encompassing their classification, current understanding of extraction, identification, and characterization using various analytical techniques, including gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), nuclear magnetic resonance (NMR) spectroscopy, and infrared (IR) spectroscopy. The article also delves into the manner in which insects perceive and respond to plant semiochemicals, as well as the impact of environmental factors on plant odor emission and insect orientation. Furthermore, it explores the underlying mechanisms by which insects perceive and interpret these chemical cues, and how this impacts their behavioral responses, including feeding habits, oviposition patterns, and mating behaviors. Additionally, the potential applications of plant semiochemicals in integrated pest management strategies are explored. This review provides insight into the intricate relationships between plants and insects mediated by semiochemicals, highlighting the significance of continued research in this field to better understand and leverage these interactions for effective pest control. [ABSTRACT FROM AUTHOR]

Compound databases of natural products play a crucial role in drug discovery and development projects and have implications in other areas, such as food chemical research, ecology and metabolomics. Recently, we put together the first version of the Latin American Natural Product database (LANaPDB) as a collective effort of researchers from six countries to ensemble a public and representative library of natural products in a geographical region with a large biodiversity. The present work aims to conduct a comparative and extensive profiling of the natural product‐likeness of an updated version of LANaPDB and the individual ten compound databases that form part of LANaPDB. The natural product‐likeness profile of the Latin American compound databases is contrasted with the profile of other major natural product databases in the public domain and a set of small‐molecule drugs approved for clinical use. As part of the extensive characterization, we employed several chemoinformatics metrics of natural product likeness. The results of this study will capture the attention of the global community engaged in natural product databases, not only in Latin America but across the world. [ABSTRACT FROM AUTHOR]

Sauce-flavor baijiu products produced in different regions have perceptible differences in flavor characteristics, but the reasons for the formation of regional flavor substances are still unclear. The brewing process of sauce-flavor baijiu includes multiple rounds of pit fermentation. The base baijiu produced at the end of pit fermentation contributes significantly to the flavor of sauce-flavor baijiu products. This study investigated the microbial community succession and changes in flavor compounds during 7th round pit fermentation of sauce-flavor baijiu produced in Beijing region and comparatively analyzed the componential differences in microbial community and flavor compounds with sauce-flavor baijiu produced in other regions. It was found that Lactobacillus, Virgibacillus, Thauera, and Kroppenstedtia were the dominant bacterial genera, and Byssochlamys, Cutaneotrichosporon, and Apiotrichum were the dominant fungal genera. A total of 47 volatile compounds were identified and quantified in fermented grains. The concentrations of ethyl L(-)-lactate, ethyl caproate, and diethyl succinate gradually decreased with time, while the concentrations of phenethyl acetate, ethyl palmitate, and ethyl phenylacetate increased. The relative abundance of dominant microorganisms as well as the concentrations of volatile compounds showed a successional pattern with fermentation time. Lactobacillus, Virgibacillus, and Kroppenstedtia were positively associated with the synthesis of ethyl phenylacetate and phenylethyl alcohol, while negatively associated with the synthesis of ethyl caproate. Differences in microbial community structure are partly responsible for the regional flavor characteristics of sauce-flavor baijiu and the flavor differences between rounds of base baijiu. This study will provide in-depth insights into the formation of regional flavor compounds of sauce-flavor baijiu. [ABSTRACT FROM AUTHOR]

The increasing incidence of tick-borne diseases and the growing resistance to conventional acaricides underscore the urgent need for innovative and sustainable tick management strategies. This study investigates the potential of assembly and sex pheromones for the control of larval stages of Rhipicephalus sanguineus, the brown dog tick, which poses significant health risks to dogs. The ticks were collected from various canine hosts in Thrissur, Kerala and subjected to Petri-dish bioassays using vapour patches impregnated with synthetic assembly pheromone (AP) and sex pheromone (SP), both individually and in combination. The efficacy of these semiochemicals was assessed based on the attraction and clustering behaviour of unfed larvae and partially fed adult ticks over a 24-hour period. Results demonstrated a significantly higher attraction to AP-impregnated patches, with notable efficacy observed in causing tick aggregation, particularly beyond 30 min of exposure. While SP also showed potential in attracting ticks, the combination of SP and AP did not result in a synergistic effect. The study highlights the potential of using semiochemicals as an environmentally sustainable alternative to traditional acaricides, highlighting their role in integrated pest management strategies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is an economically important pest of soft and stone fruit crops. The aim of this study was to identify repellents, formulated in dispensers, which could protect crops from D. suzukii. Fourteen potential repellents were screened against summer‐ and winter‐morph D. suzukii through electroantennography and behavioural bioassays. Repellents effective in the laboratory were tested in polytunnels to determine their efficacy in reducing catches in fruit‐baited traps. Further trials of three potential repellents were conducted to determine the distances over which repellent dispensers could reduce D. suzukii emergence in a strawberry crop. RESULTS: All 14 chemicals screened were detected by the antennae of both D. suzukii morphs. Hexyl acetate and geosmin both elicited a significantly greater corrected EAG response in summer morphs than winter morphs. Summer‐morph D. suzukii were repelled by butyl acetate, ethyl propionate, methyl N,N‐dimethyl anthranilate, geosmin, methyl salicylate, DEET and benzaldehyde at one or more doses test in laboratory bioassays. Winter morphs were repelled by ethyl propionate, methyl anthranilate, methyl N,N‐dimethyl anthranilate, DEET, benzaldehyde and butyl anthranilate at one or more of the doses tested in the laboratory. Ethyl propionate, methyl N,N‐dimethylanthranilate and benzaldehyde repelled both morphs from fruit‐baited traps in polytunnel trapping trials. Ethyl propionate and methyl N,N‐dimethylanthranilate reduced emergence of D. suzukii in a strawberry crop over 3–5 m. CONCLUSIONS: Ethyl propionate and methyl N,N‐dimethylanthranilate may protect strawberry crops against D. suzukii. Future work should test these repellents in combination with attractants in a 'push‐pull' strategy. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Abstract Tribolium castaneum and Rhyzopertha dominica are cosmopolitan, destructive postharvest pests. Although research has investigated how high densities of T. castaneum affect attraction to the aggregation pheromone by conspecifics, research into the behavioral response of both species to food cues after high density exposure has been lacking despite its importance to foraging ecology. Our goal was to manipulate and observe the effects of crowding on the behavioral response of both species to common food and pheromonal stimuli and to determine how the headspace emission patterns from grain differed under increasing densities. Densities of colonies for both species was altered (10–500 adults) on a fixed quantity of food (10 g of flour or whole wheat), then the behavioral response to common food and pheromonal cues was evaluated in a wind tunnel and release-recapture experiment, while volatiles were examined through gas chromatography coupled with mass spectrometry. Importantly, at least for T. castaneum, crowded conditions attenuate attraction to food-based stimuli, but not pheromonal stimuli. Crowding seemed to have no effect on R. dominica attraction to food and pheromonal stimuli in the wind tunnel, but exposure to high density cues did elicit 2.1–3.8-fold higher captures in traps. The relative composition and abundance of headspace volatiles emitted varied significantly with different densities of beetles and was also species-specific. Overall, our results have implications for expanding our understanding of the foraging ecology of two economically important pests.

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]

Beauveria bassiana is an entomopathogenic fungus that parasitizes and kills insects. The role of volatile organic compounds (VOCs) emitted by B. bassiana acting as semiochemicals during its interaction with lepidopterans is poorly explored. Here, we studied the effect of VOCs from B. bassiana and 3-methylbutanol (as a single compound) on the feeding behavior of L2 larvae of Spodoptera frugiperda in sorghum plants. Additionally, we assessed whether fungal VOCs induce chemical modifications in the plants that affect larval food preferences. Metabolomic profiling of plant tissues was performed by mass spectrometry and bioassays in a dual-choice olfactometer. The results showed that the larval feeding behavior was affected by the B. bassiana strain AI2, showing that the insect response is strain-specific. Furthermore, 80 µg of 3-methylbutanol affected the number of bites. The larval feeding choice was dependent on the background context. Fragment spectra and a matching precursor ion mass of 165.882 m/z enabled the putative identification of 4-coumaric acid in sorghum leaves exposed to fungal VOCs, which may be associated with larval deterrent responses. These results provide valuable insights into the bipartite interaction of B. bassiana with lepidopterans through VOC emission, with the plant as a mediator of the interaction. [ABSTRACT FROM AUTHOR]

The red flour beetle, Tribolium castaneum, is the most common coleopteran pest that infests different kinds of stored grains and flours. Under natural conditions, T. castaneum adults secrete benzoquinones as cuticular semiochemicals for aggregation and defensive purposes. In this study, we have examined the physico-chemical effects on the secretion of cuticular semiochemicals in T. castaneum. Adult beetles were exposed to different food flours, starvation, cold, heat and chemical treatments. After 24 h of exposures, cuticular surface chemicals were extracted and analyzed using gas chromatography–mass spectrometry (GC–MS) and gas chromatography–flame ionization detector (GC–FID) techniques. Totally, 14 compounds were identified as cuticular surface chemicals from the body surface of beetles. When exposed to different food flours (chickpea, green gram, rice and wheat), there were no remarkable variations in the secretion of cuticular surface chemicals. Whereas under starvation, cold, heat and chemical stress conditions, remarkable variations (significantly at P ≤ 0.05) were observed in 2-methyl-p-benzoquinone, 2-ethyl-p-benzoquinone and 1-pentadecene secretions. Remarkably, maximum 99.30, 98.79 and 77.41% reductions were observed in 2-methyl-p-benzoquinone, 2-ethyl-p-benzoquinone and 1-pentadecene secretions due to the effect of diallyl disulfide chemical stress, respectively, with the significance of P ≤ 0.05. In conclusion, it was predicted that starvation, cold, heat and chemical stress conditions alter 2-methyl-p-benzoquinone, 2-ethyl-p-benzoquinone and 1-pentadecene secretions in T. castaneum adults rather than food flours. [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]

Recently, an outbreak of Ips sexdentatus (Börner, 1776) has caused considerable damage in the pine forests of the Czech Republic. As historical data on the biology of this pest are scarce due to its rare occurrence in recent decades, our work focused on monitoring flight activity and voltinism and investigating methods for monitoring its activity during the growing season. Observations were conducted from March to September 2021 and 2022 at three sites using 12 Theysohn traps with four types of pheromone lures (ACUMIPROTECT, ACUWIT, SEXOWIT and Pheagr IAC) together with data loggers to record weather conditions. The first beetles occurred in early May (daily mean temperatures above 13 °C). After the first egg laying stage, females re-emerged to establish a sister brood. The maximum flight activity appeared between late June and mid-July (daily mean temperatures about 20 °C), and the offspring occurred at the turn of June/July and in the first half of August. Since then, flight activity had a downward trend and quietened in September. According to the data, monitoring of I. sexdentatus should be conducted between May and September using the ACUMIPROTECT pheromone bait exhibiting the highest capturing efficacy. In future, however, the behavior of I. sexdentatus might alter due to climate change. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Angoumois grain moth, Sitotroga cerealella, is a destructive pest of maize, wheat, and rice, causing economic losses and threatening food security. This study aimed to develop and characterize microcapsules of mesoporous silica nanospheres (MSN) and cyclodextrin‐modified mesoporous silica nanospheres (CDMSN) containing two aldehydes, nonanal and decanal, found in plant essential oils, to assess their attractiveness to S. cerealella populations. RESULTS: Microcapsules with 2:1 ratio of nonanal and decanal exhibited an average encapsulation efficiency of 39.82% for MSN loaded with nonanal and decanal (MSN‐ND) and 46.10% for CDMSN loaded with nonanal and decanal (CDMSN‐ND). They have an elliptical shape with particle sizes of 115 nm for MSN and 175 nm for CDMSN. Gas chromatography–mass spectrometry analysis revealed in vitro release of nonanal in MSN at 96.24% and decanal at 96.42% by the 36th day. CDMSN showed releases of 93.83% for nonanal and 93.74% for decanal by the 50th day. CDMSN‐ND attracted adult S. cerealella for 43 days, while MSN‐ND remained effective for 29 days. In mass trapping assays in simulated grain warehouse, both MSN‐ND and CDMSN‐ND trapped over 50% of the adult population within 7 days, significantly reducing grain infestation rates below 10% by inhibiting F1 adult emergence. At temperatures ranging from 20 °C to 35 °C, both microcapsules exhibited significant and effective attraction rates for S. cerealella. Stored wheat seeds treated with CDMSN and CDMSN‐ND over 1 year showed no significant differences in key germination parameters. CONCLUSION: Microencapsulated nonanal and decanal offer a promising, sustainable approach for controlling S. cerealella infestation in stored grains, contributing to global food security. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study investigates the efficacy of combined treatment strategy, incorporating pheromones for bark beetle I. typographus (IT) and attractant of its natural enemy T. formicarius (TF), along with anti-attractants for IT (containing 1-hexanol, 1-octen-3-ol, 3-octanol, eucalyptol, trans-thujanol, and transconophthorin), to enhance protection methods for Picea abies against biotic disturbances. Two field experiments--trapping experiment and tree protection experiment--were conducted in June 2023 in managed spruce-dominated beetle-affected stands in Czechia. We anticipated higher catches of IT in traps baited with IT pheromone (containing s-ipsdienol, s-cis-verbenol, and 2methyl-3-buten-2-ol) and TF attractant compared to traps using IT pheromone alone, since compounds intrinsic to IT pheromone, namely 2-methyl-3-buten2-ol, ipsenol, and ipsdienol, are integral components of the attractant designed for TF. We hypothesized that application of TF attractant and IT anti-attractant would enhance the treatment's protective properties, assuming that attracted TF would function as a predator, reducing bark beetle population and increasing tree survival rates. Semiochemical composition declared by the producers was verified using gas chromatography-mass spectrometry analysis. In the trapping experiment, EcoTrap-type traps were baited with six combinations of lures and anti-attractant. In the tree protection experiment, 28 mature Norway spruce trees situated at newly created forest edges underwent four treatment types: TF attractant, IT anti-attractant, their combination, and no treatment ("control"). Traps baited solely with TF attractant did not capture either beetle, whereas traps lured with IT pheromone, TF attractant and anti-attractant showed no captures of IT but recorded the highest numbers of TF, suggesting significant potential for combined treatment e_cacy. Surprisingly, tree mortality was observed exclusively among trees treated only with TF attractant and in their vicinity, suggesting unique bark beetles' response to the mixture of predator's attractant and host tree kairomones, a phenomenon that was not previously reported. Application of anti-attractant and TF treatment effectively prevented tree mortality, demonstrating the repellent potential of IT anti-attractant against bark beetles. However, mortality rates showed no significant differences among control trees, those treated with anti-attractants, or those treated with the combination of anti-attractants and TF attractant, underscoring necessity for further research to optimize treatment efficacy. [ABSTRACT FROM AUTHOR]

Tribolium castaneum and Rhyzopertha dominica are cosmopolitan, destructive postharvest pests. Although research has investigated how high densities of T. castaneum affect attraction to the aggregation pheromone by conspecifics, research into the behavioral response of both species to food cues after high density exposure has been lacking despite its importance to foraging ecology. Our goal was to manipulate and observe the effects of crowding on the behavioral response of both species to common food and pheromonal stimuli and to determine how the headspace emission patterns from grain differed under increasing densities. Densities of colonies for both species was altered (10–500 adults) on a fixed quantity of food (10 g of flour or whole wheat), then the behavioral response to common food and pheromonal cues was evaluated in a wind tunnel and release-recapture experiment, while volatiles were examined through gas chromatography coupled with mass spectrometry. Importantly, at least for T. castaneum, crowded conditions attenuate attraction to food-based stimuli, but not pheromonal stimuli. Crowding seemed to have no effect on R. dominica attraction to food and pheromonal stimuli in the wind tunnel, but exposure to high density cues did elicit 2.1–3.8-fold higher captures in traps. The relative composition and abundance of headspace volatiles emitted varied significantly with different densities of beetles and was also species-specific. Overall, our results have implications for expanding our understanding of the foraging ecology of two economically important pests. [ABSTRACT FROM AUTHOR]

Intraspecific and habitat-mediated responses to chemical cues play key roles in structuring populations of marine species. We investigated the behaviour of herbivorous-stage juvenile crown-of-thorns sea stars (COTS; Acanthaster sp.) in flow-through choice chambers to determine if chemical cues from their habitat influence movement and their transition to become coral predators. Juveniles at the diet transition stage were exposed to cues from their nursery habitat (coral rubble-crustose coralline algae (CCA)), live coral and adult COTS to determine if waterborne cues influence movement. In response to CCA and coral as sole cues, juveniles moved towards the cue source and when these cues were presented in combination, they exhibited a preference for coral. Juveniles moved away from adult COTS cues. Exposure to food cues (coral, CCA) in the presence of adult cues resulted in variable responses. Our results suggest a feedback mechanism whereby juvenile behaviour is mediated by adult chemical cues. Cues from the adult population may deter juveniles from the switch to corallivory. As outbreaks wane, juveniles released from competition may serve as a proximate source of outbreaks, supporting the juveniles-in-waiting hypothesis. The accumulation of juveniles within the reef infrastructure is an underappreciated potential source of COTS outbreaks that devastate coral reefs. [ABSTRACT FROM AUTHOR]

Background: Insects rely on sophisticated sensitive chemosensory systems to sense their complex chemical environment. This sensory process involves a combination of odorant receptors (ORs), gustatory receptors (GRs) and ionotropic receptors (IRs) in the chemosensory system. This study focused on the identification and characterization of these three types of chemosensory receptor genes in two closely related Phthorimaea pest species, Phthorimaea operculella (potato tuber moth) and Phthorimaea absoluta (tomato leaf miner). Results: Based on manual annotation of the genome, we identified a total of 349 chemoreceptor genes from the genome of P. operculella, including 93 OR, 206 GR and 50 IR genes, while for P. absoluta, we identified 72 OR, 122 GR and 46 IR genes. Through phylogenetic analysis, we observed minimal differences in the number and types of ORs and IRs between the potato tuber moth and tomato leaf miner. In addition, we found that compared with those of tomato leaf miners, the gustatory receptor branch of P. operculella has undergone a large expansion, which may be related to P. absoluta having a narrower host range than P. operculella. Through analysis of differentially expressed genes (DEGs) of male and female antennae, we uncovered 45 DEGs (including 32ORs, 9 GRs, and 4 IRs). Conclusions: Our research provides a foundation for exploring the chemical ecology of these two pests and offers new insights into the dietary differentiation of lepidopteran insects, while simultaneously providing molecular targets for developing environmentally friendly pest control methods based on insect chemoreception. [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]

Simple Summary: Interspecific competition occurs when two or more species require similar resources. Competition could be avoided by selecting a habitat with fewer competitors. While this behavior is well known, the identification mechanism is poorly understood. Mosquitoes select larval habitats during oviposition, and high competitor densities reduce larval survival. In this study, we show that ovipositing mosquito females can detect and avoid pools containing crowding signals originating from interspecific larvae. Furthermore, when larvae were not crowded, the habitat was found to be attractive to conspecifics. These findings increase our understanding of signals affecting mosquito oviposition, competitor recognition, and habitat selection under competition conditions. Numerous species of animals alter their behavior in response to increasing competition. To do so, they must possess the ability to detect the presence and density of interspecific competitors. We studied the role of semiochemicals released by increasing densities of larval Culiseta longiareolata Macquart on female oviposition habitat selection in two field experiments. Similarly to C. longiareolata larvae, subordinate Culex laticinctus Edwards are periphyton grazers who dwell in rain-filled pools in the Mediterranean region. We show that C. laticinctus females oviposited significantly less in mesocosm pools that were treated with crowding signals originating from C. longiareolata larvae. In the second experiment, we placed a similar number of larvae directly inside the 50 L mesocosms. These low-density mesocosms did not affect C. laticinctus oviposition but were attractive to conspecific oviposition. These results increase our understanding of the female ability to detect species-specific signals, indicating increased larval competition. [ABSTRACT FROM AUTHOR]

Female mate choice decisions are guided by preferences for male display features, but in chorusing species the displays of different males may temporally overlap. Here, mate choice decisions may be guided by preferences based on signal timing in addition to signal features. Which type of preference dominates has implications for our understanding of the dynamics of sexual selection in group-displaying animals. I presented female treefrogs with a series of playback treatments varying the amounts of calls in leader/follower position to establish the lowest proportion of leading calls resulting in a preference. About half the females expressed leader preferences when fewer than 15% of calls are in leading position (the maximum produced by chorusing males). This suggests that mate choice decisions will be dominated by call timing preferences in some females, and by call features preferences others, overall lowering the strength of selection on either male display trait. [ABSTRACT FROM AUTHOR]

Early detection of invasive species is critical for preventing ecological and economic damage and maintaining ecosystem health. In Hawaiʻi, a complex of generalist ambrosia beetle species in the tribe Xyleborini (Coleoptera: Scolytinae) are threatening the health and productivity of forests and crops due to their association with tree diseases such as rapid ʻōhiʻa death (ROD) and key agricultural commodities including coffee and macadamia.We conducted trapping experiments to determine the efficacy of semiochemicals to attract and repel Xyleborini ambrosia beetles within two ʻōhiʻa (Metrosideros polymorpha) forests on the Island of Hawaiʻi. We compared the attraction of beetles to 100% ethanol and a 1:1 mixture of ethanol: methanol at Waiākea Forest Reserve and ʻŌlaʻa Forest in Hawaiʻi Volcanoes National Park. In addition, we tested the extent to which verbenone and verbenone + methyl salicylate repellents (SPLAT® Verb and SPLAT® Beetle Guard, respectively) deterred beetles from baited traps at Waiākea Forest Reserve in two separate experiments.For all invasive ambrosia beetle species, including Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xyleborus perforans, Xylosandrus compactus, and Xylosandrus crassiusculus, more beetles were captured in traps baited with 100% ethanol than 1:1 ethanol: methanol. Across all species, both repellents were effective, with fewer beetles captured in traps equipped with repellents.Our research demonstrates the utility of semiochemicals for attracting and repelling invasive ambrosia beetle species in Hawaiʻi, and the potential use of these tools for early detection and management strategies. [ABSTRACT FROM AUTHOR]

Leaf‐cutting ants (LCAs) cause significant damage to forest plantations and are mainly managed by broad‐spectrum synthetic insecticides. In Patagonia, Pinus ponderosa (Pinales: Pinaceae) (Douglas 1836) and Pinus contorta (Pinales: Pinaceae) (Dluglas 1838) are the predominant pine species in forest plantations. Previous research has shown that dehydrated citrus pulp is an LCAs attractant, and tea tree essential oil acts as an LCAs repellent.We evaluated the use of dehydrated citrus pulp and tea tree oil to manage LCAs behaviour in a push–pull setting, using mixed pine species in small plot fields, to reduce the LCA Acromyrmex lobicornis (Hymenoptera: Formicidae) (Emery, 1888) damage in young P. ponderosa plants. We combined the treatment with attractant and repellent in a mono‐specific plantation design (three ponderosa plants surrounded with pulp and three sprayed with tea tree extract) or mixed plantation designs (three contorta plants with pulp and three ponderosa plants with tea tree).The combination of both mono‐specific and mixed plantations with push–pull stimuli delayed discovery and decreased the damage in pines sprayed with the repellent. Mono‐specific as well as mixed species designs were equally effective, reducing ant damage and increasing ~50% the survival probability of P. ponderosa when push–pull stimuli were applied.The use of a push–pull strategy with plant‐based compounds provides potential as a management tool that reduces and delays LCA damage in pine trees. [ABSTRACT FROM AUTHOR]

Simple Summary: Insects are covered with chemicals called hydrocarbons that are involved in chemical communication (mainly in mating) as well as in preventing the insect from drying out and protecting it from harmful environmental factors. Although we know a great deal about these molecules in laboratory strains, little is known about their variation and evolution in nature. We studied Drosophila melanogaster flies from Dijon, France, which we captured using traps baited with various fruits. We set up lines from these flies and studied their hydrocarbons on capture and after up to 40 generations in the laboratory. We initially observed a lot of natural variability, but this soon became more limited as the strains adapted to life in the laboratory. In some of the lines, females flies had a hydrocarbon profile previously seen only in tropical populations: this may indicate that this globally distributed species is adapting to increased temperatures caused by climate change. These hydrocarbons can be used as sensitive markers of climate change, as long as they are studied before insects become adapted to laboratory conditions. Experimental studies of insects are often based on strains raised for many generations in constant laboratory conditions. However, laboratory acclimation could reduce species diversity reflecting adaptation to varied natural niches. Hydrocarbons covering the insect cuticle (cuticular hydrocarbons; CHCs) are reliable adaptation markers. They are involved in dehydration reduction and protection against harmful factors. CHCs can also be involved in chemical communication principally related to reproduction. However, the diversity of CHC profiles in nature and their evolution in the laboratory have rarely been investigated. Here, we sampled CHC natural diversity in Drosophila melanogaster flies from a particular location in a temperate region. We also measured cis-Vaccenyl acetate, a male-specific volatile pheromone. After trapping flies using varied fruit baits, we set up 21 D. melanogaster lines and analysed their pheromones at capture and after 1 to 40 generations in the laboratory. Under laboratory conditions, the broad initial pheromonal diversity found in male and female flies rapidly changed and became more limited. In some females, we detected CHCs only reported in tropical populations: the presence of flies with a novel CHC profile may reflect the rapid adaptation of this cosmopolitan species to global warming in a temperate area. [ABSTRACT FROM AUTHOR]