Search

In traditional digital filing systems, people mostly use text as a key to categorise images, and retrieve them in the future. The use of other media as keys for image retrieval is rarely used, notwithstanding that multisensory digital media – mulsemedia – can be harnessed to improve users' performance and help them to retrieve their images. In this respect, olfactory media (engaging the sense of smell) is an example, as people can categorise their images by using congruent olfactory media. Accordingly, we investigated the impact of employing olfactory media as a key for retrieving a set of images. Moreover, we also studied the impact of the usage of olfactory media in this context on a user's performance and Quality of Experience (QoE). To this end, we developed an olfactory-enhanced application (SCENT2IMAGE) in which olfactory media was emitted alongside a 5X5 matrix of images, of which users had to recognize 4 images congruent with the emitted scents. Furthermore, we developed a word-only version of the application (WORD2IMAGE) in which words alone were used as an equivalent key instead of olfactory media. Forty-four participants were invited and took part in our experiment, evenly split into a control and experimental group. Results highlight that using olfactory media does have a significant impact on user performance by helping them find related images. Moreover, using olfactory effects in this context was also found to enhance user QoE. Lastly, our findings underscore that users were willing to use olfactory-enhanced applications for categorizing/retrieving their albums and images. [ABSTRACT FROM AUTHOR]

Simple Summary: The sweet potato whitefly is a major global pest in vegetable production. The management of this pest has typically relied heavily on insecticide treatments. Many populations of sweet potato whitefly are now resistant to insecticides. Therefore, alternative means to control this pest are needed. Many predatory insects consume sweet potato whiteflies, so helping lure and attract both predators and the pest to the same location could improve control. This study investigates attractive odors for sweet potato whiteflies and two predator species that could be used to improve sweet potato whitefly pest management. Traditionally, olfaction was thought to play a minor role in the behavioral ecology of the sweet potato whitefly, Bemisia tabaci (Gennadius). However, recent research is uncovering significant potential for whitefly management based on olfaction. Incorporating chemical attractants with standard whitefly management programs could significantly improve control. The integration of attractants with biological control is exceptionally promising. Therefore, the behavioral response of B. tabaci and two generalist predators to the green leaf volatiles (E)-2-hexenal, (Z)-3-hexenal, (Z)-3-hexenyl acetate, and (Z)-3-hexe-1-ol were investigated in Y-tube olfactometers. Three of the four green leaf volatiles resulted in the attraction of female B. tabaci. Blend optimization indicated a two-chemical blend to be the most attractive blend for female B. tabaci. In addition, this blend was attractive to female Macrolophus praeclarus (Distant) but did not elicit a behavioral response from either male or female Delphastus catalinae (Horn). The two-chemical blend of green leaf volatiles could be further developed as a lure to attract B. tabaci and its predator, M. praeclarus. [ABSTRACT FROM AUTHOR]

AbstractTo enhance the engagement and significance of olfaction as a novel medium in multimedia systems, we aim to integrate different hedonic odorous cues into narratives to augment immersion in virtual experiences. We introduce the ScentClue system, comprising (1) an original and murder-themed experimental film incorporating four distinct hedonic odor cues synchronized with audiovisual elements, (2) a neck-worn scent delivery device capable of dispensing four different odors, and (3) an Unreal Engine-based virtual cinema environment enabling rapid control of video playback and odor dissemination. Experimenting with 18 participants divided into control groups with and without odor stimuli, we validated the system’s usability and effectiveness of odor cue settings. Furthermore, we found that the use of odors with different hedonic qualities could enhance odor recognition, amplify thematic story ambiance, and aid in the rapid differentiation of complex relationships. Finally, we discussed expanded scenarios and interaction modalities for ScentClue, proposing future narrative-driven olfaction-enhanced multimedia designs with considerations for odor cue settings, odor material selection, and scent-releasing setup, particularly unpleasant odors. [ABSTRACT FROM AUTHOR]

Abstract Olfactory cues are considered a new sensory medium that can enhance learning, but the lack of empirical data has hampered their widespread use in educational practice. This requires empirical research to explore the effects of olfactory cues on learning. To address this research need, an experimental research study was conducted among 87 fourth graders from a Chinese elementary school. It explored the innovative design of adding olfactory cues to text materials by examining their effects on retention and schemata construction as learning outcomes, as well as their influence on learners’ cognitive load and learning experience. In this between-subjects design experiment, the experimental group (n = 44) learned text materials with the introduction of olfactory cues, while the control group (n = 43) only learned text materials. After the learning activity, participants were asked to complete the questionnaires, immediate test, and delayed test. The results revealed that the usage of olfactory cues synchronized with text materials can enhance delayed retention, facilitate schemata construction, and improve learner experience without increasing cognitive load. This study confirms the potential of well-designed olfactory cues in educational practice and provides insights for designing and presenting multimedia learning resources.

Summary: Mimicry is the phenomenon in which one species (the mimic) closely resembles another (the model), enhancing its own fitness by deceiving a third party into interacting with it as if it were the model. In plants, mimicry is used primarily to gain fitness by withholding rewards from mutualists or deterring herbivores cost‐effectively. While extensive work has been documented on putative defence mimicry, limited investigation has been conducted in the field of chemical mimicry.In this study, we used field experiments, chemical analyses, behavioural assays, and electrophysiology, to test the hypothesis that the birthwort Aristolochia delavayi employs chemical mimicry by releasing leaf scent that closely resembles stink bug defensive compounds and repels vertebrate herbivores.We show that A. delavayi leaf scent is chemically and functionally similar to the generalized defensive volatiles of stink bugs and that the scent effectively deters vertebrate herbivores, likely through the activation of TRPA1 channels via (E)‐2‐alkenal compounds.This study provides an unequivocal example of chemical mimicry in plants, revealing intricate dynamics between plants and vertebrate herbivores. Our study underscores the potency of chemical volatiles in countering vertebrate herbivory, urging further research to uncover their potentially underestimated importance. [ABSTRACT FROM AUTHOR]

Carnivorous mammals have been reported to feed on fleshy fruits and disperse seeds, but these interactions are seldom observed and are poorly understood in hyper‐arid regions. Scent may play a key role in these interactions, given that most carnivores have sensitive olfactory systems and dichromatic vision. The !nara (Acanthosicyos horridus: Cucurbitaceae) in the Namib Desert produces large (10–20 cm diameter) melons that remain green while undergoing increased volatile emissions with a changing chemical profile as they ripen. Using extensive camera trapping, we found that the fruits are consumed mainly by black‐backed jackals (Canis mesomelas) and rarely also by other carnivores such as cape fox (Vulpes chama) and brown hyaena (Hyaena brunnea). We found that scent cues play a crucial role as jackals mainly sought fruits at night and easily located ripe fruits that were experimentally buried beneath the sand to remove visual cues. Seeds retrieved from jackal scat showed improved germination relative to un‐ingested seeds. This study highlights the importance of fruit scent in mediating seed dispersal mutualisms involving carnivores. [ABSTRACT FROM AUTHOR]

Traditionally, olfaction was thought to play a minor role in the behavioral ecology of the sweet potato whitefly, Bemisia tabaci (Gennadius). However, recent research is uncovering significant potential for whitefly management based on olfaction. Incorporating chemical attractants with standard whitefly management programs could significantly improve control. The integration of attractants with biological control is exceptionally promising. Therefore, the behavioral response of B. tabaci and two generalist predators to the green leaf volatiles (E)-2-hexenal, (Z)-3-hexenal, (Z)-3-hexenyl acetate, and (Z)-3-hexe-1-ol were investigated in Y-tube olfactometers. Three of the four green leaf volatiles resulted in the attraction of female B. tabaci. Blend optimization indicated a two-chemical blend to be the most attractive blend for female B. tabaci. In addition, this blend was attractive to female Macrolophus praeclarus (Distant) but did not elicit a behavioral response from either male or female Delphastus catalinae (Horn). The two-chemical blend of green leaf volatiles could be further developed as a lure to attract B. tabaci and its predator, M. praeclarus.

Mate choice is hypothesized to play an important role in maintaining high diversity at major histocompatibility complex (MHC) genes in vertebrates. Many studies have revealed that females across taxa prefer the scent of males with MHC genotypes different to their own. In this study we tested the "opposites‐attract" hypothesis in two species of darter with known differences in female criteria used in mate choice: in the fantail darters (a paternal‐care species), females prefer males with visual traits related to nest guarding and egg tending, while in rainbow darters (not a paternal‐care species) female mate choice criteria are unknown. In dichotomous mate‐choice trials, we presented females of both species with the scents of conspecific males with MHC class IIb genotypes that were either similar or dissimilar to that of the focal female. We evaluated the proportion of time each female spent with each male and calculated the average strength of female preference for both species. Female fantail darters demonstrated a preference for the scent of males with similar (rather than dissimilar) MHC genotypes, but this result was not statistically significant. Rainbow darter females showed no preference for the scent of males with similar or dissimilar MHC genotypes. Our results do not support the "opposites‐attract" hypothesis in darters. [ABSTRACT FROM AUTHOR]

Chemosensory science, the study of how organisms produce and assess olfactory information, is central to our understanding of how organisms interact and gain information about their environment. Signaling cue identification in aquatic systems lags behind our knowledge in terrestrial insects due to analytical challenges in aqueous environments. Unambiguous, reliable, and fast behavioral assays to evaluate the biological activity and function of a chemosensory cue are critical to understand aquatic signaling systems and enable research into their ecology, evolution, and threats in a changing environment. Yet, a range of anthropomorphic assumptions made in this research field create additional challenges to interpret data generated. Here, we evaluate common challenges including assumed readiness of individuals to respond, lack of information on the animals' physiological and social status, their pre-experimental cue exposure, the innate or learned character of the responses, the animals' acclimation and habituation status, and the impact of the animals upon their own environment. These factors lead to significant variability in animals' responses in bioassays, both in the field and in laboratory setups. In the light of our limited knowledge of aquatic chemosensory cues' chemical structure, active concentrations in samples, and undetermined response thresholds, we evaluate methods of mitigation to minimize differences between studies. We conclude that currently it is nearly impossible to compare results from chemosensory behavioral studies undertaken in different ecosystems, laboratories, and time points. There is an urgent need for the standardization of behavioral methods, recording of environmental conditions, and individuals' physiology, physical, and social status, to avoid conflicting and contradicting results when comparing studies. Including these parameters in experimental design and data interpretation will provide a deeper understanding of chemosensory communication, reduce unconscious bias in studies, and can help to explain the substantial individuality in animals' responses to chemosensory cues and their acclimation to environmental stress. [ABSTRACT FROM AUTHOR]

Floral scent is a key olfactory cue in both diurnal and nocturnal pollination systems. In the case of nocturnal systems, such as bat‐pollinated flowers, odour seems to play a more important role than visual cues. Cactaceae include many bat‐pollinated species; however, few studies have investigated the olfactory cues in this family.We analysed and compared the chemical composition of the floral bouquet of three chiropterophilous cactus species, among which are a pair of congeners that differ considerably in scent intensity.Our research presents novel findings regarding the floral scent chemistry of chiropterophilous cactus species. We documented the first case of a bat‐pollinated cactus whose flowers lack perceptible floral scent and in which no volatile compounds were detected in our chemical analyses. Additionally, we provide a comprehensive analysis of the chemical composition of the floral bouquet of the other two bat‐pollinated species, revealing a resemblance among closely related species within the same genus.We highlight the need for further studies using biotests to investigate the mechanisms through which bats find flowers lacking scent. [ABSTRACT FROM AUTHOR]

The olive fruit fly (Bactrocera oleae) (Rossi) is the most economically important insect pest in many olive cultivation areas worldwide. However, levels of infestation by this pest show remarkable variability, even among orchards in close proximity to one another. While the factors driving this variability remain uncertain, there is evidence that the presence of native plants species can influence pest populations in agro‐ecosystems via various mechanisms, suggesting that variation in the composition of understorey plant communities might plausibly play a role. In this study, we first used field trapping and plant community surveys to explore the effect of the native understorey plants Cistus creticus (Cistaceae), Lavandula stoechas (Lamiaceae), Origanum onites (Lamiaceae) and Sarcopoterium spinosum (Rosaceae) on the abundance of B. oleae across 40 olive orchards on Lesvos Island (Greece). These four plant species are widely spread in many olive orchards. Our results revealed a relationship between the plant community and the intensity of flies captured in McPhail traps, and identified the plant species C. creticus and S. spinosum whose presence was negatively correlated with fly abundance (estimate = −0.047, −0.091, respectively). The subsequent laboratory behavioural experiments revealed that exposure to olfactory cues from C. creticus and S. spinosum reduced fly attraction to odours from the olive host (Olea europaea) by 10%. These results thus reveal a relationship between the infestation levels by B. oleae and the composition of the plant community in olive orchards on Lesvos and suggest a plausible mechanism via which olfactory cues from native aromatic species might influence fly recruitment. More generally, these findings highlight the potentially important role of understorey communities in mediating resistance to B. oleae and other agricultural pests. [ABSTRACT FROM AUTHOR]

Abstract Mate choice is hypothesized to play an important role in maintaining high diversity at major histocompatibility complex (MHC) genes in vertebrates. Many studies have revealed that females across taxa prefer the scent of males with MHC genotypes different to their own. In this study we tested the “opposites‐attract” hypothesis in two species of darter with known differences in female criteria used in mate choice: in the fantail darters (a paternal‐care species), females prefer males with visual traits related to nest guarding and egg tending, while in rainbow darters (not a paternal‐care species) female mate choice criteria are unknown. In dichotomous mate‐choice trials, we presented females of both species with the scents of conspecific males with MHC class IIb genotypes that were either similar or dissimilar to that of the focal female. We evaluated the proportion of time each female spent with each male and calculated the average strength of female preference for both species. Female fantail darters demonstrated a preference for the scent of males with similar (rather than dissimilar) MHC genotypes, but this result was not statistically significant. Rainbow darter females showed no preference for the scent of males with similar or dissimilar MHC genotypes. Our results do not support the “opposites‐attract” hypothesis in darters.

Chemosensory science, the study of how organisms produce and assess olfactory information, is central to our understanding of how organisms interact and gain information about their environment. Signaling cue identification in aquatic systems lags behind our knowledge in terrestrial insects due to analytical challenges in aqueous environments. Unambiguous, reliable, and fast behavioral assays to evaluate the biological activity and function of a chemosensory cue are critical to understand aquatic signaling systems and enable research into their ecology, evolution, and threats in a changing environment. Yet, a range of anthropomorphic assumptions made in this research field create additional challenges to interpret data generated. Here, we evaluate common challenges including assumed readiness of individuals to respond, lack of information on the animals’ physiological and social status, their pre-experimental cue exposure, the innate or learned character of the responses, the animals’ acclimation and habituation status, and the impact of the animals upon their own environment. These factors lead to significant variability in animals’ responses in bioassays, both in the field and in laboratory setups. In the light of our limited knowledge of aquatic chemosensory cues’ chemical structure, active concentrations in samples, and undetermined response thresholds, we evaluate methods of mitigation to minimize differences between studies. We conclude that currently it is nearly impossible to compare results from chemosensory behavioral studies undertaken in different ecosystems, laboratories, and time points. There is an urgent need for the standardization of behavioral methods, recording of environmental conditions, and individuals’ physiology, physical, and social status, to avoid conflicting and contradicting results when comparing studies. Including these parameters in experimental design and data interpretation will provide a deeper understanding of chemosensory communication, reduce unconscious bias in studies, and can help to explain the substantial individuality in animals’ responses to chemosensory cues and their acclimation to environmental stress.

Recolonization of predators to their former ranges is becoming increasingly prevalent. Such recolonization places predators among their prey once again; the latter having lived without predation (from such predators) for a considerable time. This renewed coexistence creates opportunities to explore predation ecology at both fundamental and applied levels. We used a paired experimental design to investigate white‐tailed deer risk allocation in the Upper and Lower Peninsulas (UP and LP) in Michigan, USA. Wolves are functionally absent in the LP, while deer in the UP coexist with a re‐established wolf population. We treated 15 sites each in UP and LP with wolf olfactory cues and observed deer vigilance, activity, and visitation rates at the interface of habitat covariates using remote cameras. Such a paired design across wolf versus no‐wolf areas allowed us to examine indirect predation effects while accounting for confounding parameters such as the presence of other predators and human activity. While wolf urine had no effect across most metrics in both UP and LP, we observed differences in deer activity in areas with versus without wolves. Sites treated with wolf urine in the UP showed a reduction in crepuscular deer activity, compared to control/novel‐scent treated sites. Furthermore, we observed a strong positive effect of vegetation cover on deer vigilance in these sites. This indicates that simulated predator cues likely affect deer vigilance more acutely in denser habitats, which presumably facilitates predation success. Such responses were however absent among deer in the LP that are presumably naïve toward wolf predation. Where human and non‐human predators hunt shared prey, such as in Michigan, predators may constrain human hunting success by increasing deer vigilance. Hunters may avoid such exploitative competition by choosing hunting/bait sites located in open areas. Our results pertaining to fundamental predation ecology have strong applied implications that can promote human–predator coexistence. [ABSTRACT FROM AUTHOR]

BACKGROUND: Monitoring is an integral component of integrated pest management (IPM) programmes used to inform crop management decisions. Vine weevil, Otiorhynchus sulcatus F. (Coleoptera: Curculionidae), continues to cause economically significant losses in horticultural crops due to an inability to reliably detect the presence of this species before crop damage occurs. To improve vine weevil monitoring we investigated the behavioural responses of adult vine weevils to visual (monitoring tool shade/colour, height and diameter as well as the effect of monitoring tool and plant density) and olfactory (host plant and conspecifics) cues under glasshouse conditions. RESULTS: Monitoring tool shade, height and diameter all influenced monitoring tool efficacy, with individuals exhibiting a preference for black, tall and wide monitoring tools. The total number of individuals recorded in monitoring tools increased with monitoring tool density. By contrast, plant density did not influence the number of individuals recorded in monitoring tools. Yew‐baited monitoring tools retained a larger number of individuals compared to unbaited ones. Similarly, more vine weevils were recorded in monitoring tools baited with yew and conspecifics than in unbaited monitoring tools or those baited with only yew. Baiting monitoring tools with conspecifics alone did not enhance the number of vine weevils recorded in monitoring tools. CONCLUSIONS: Our study confirms that visual and olfactory cues influence vine weevil behaviour. This provides information on key factors that influence vine weevil monitoring tool efficacy and can be used to inform the development of a new monitoring tool for this pest. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Abstract Background Cowpea seed beetle, Callosobruchus maculatus (L.) (Coleoptera: Chrysomelidae: Bruchinae), is the most important pest of stored cowpea in tropical regions. This study was designed to determine the presence of parasitoids associated with C. maculatus, investigate the efficacy of the parasitic wasp, Dinarmus basalis Rondani (Hymenoptera: Pteromalidae), in controlling C. maculatus as influenced by time and number of applications and ascertain the use of olfactory cues by D. basalis in host searching. Three markets in Ibadan, Southwest Nigeria, namely: Bodija, Mapo and Ojoo, were purposively surveyed for parasitoids associated with C. maculatus. Two pairs of D. basalis were released at 3-day intervals into cowpea seeds previously infested with C. maculatus. Treatments included: four times of parasitoid applications (4-TPA), three applications (3-TPA), two applications (2-TPA), 1 application (1-TPA) and a control without parasitoid application (0-TPA). All treatments were replicated four times in a completely randomized design to determine F1 progeny of C. maculatus and seed damage. Olfactory bioassay was carried out with D. basalis adults placed in a Y-tube olfactometer; and their preference for infested or uninfested three cowpea varieties, namely: Ife Brown, Ife BPC (Branching Peduncle) and Oloyin, as well as infested cowpea grains or pure air was evaluated. Results Among the previously known parasitoids associated with C. maculatus, only D. basalis was found in the sampled markets. F1 progeny of adult C. maculatus reduced from 4.75 individuals (0-TPA) to 1.25 (2-TPA), 0.25 (3-TPA) and 0 (4-TPA). Concurrently, the number of exit holes on cowpea seeds significantly (p 3.21 (1-TPA) > 2.20 (2-TPA) > 2.18 (4-RAP) > 1.39 (3-TPA). Adults D. basalis were more attracted to infested grains of Ife Brown (χ 2 = 4, df = 1, p = 0.0455) and infested grains of Ife BPC (χ 2 = 4, df = 1, p = 0.0455) than clean air. Similarly, adults D. basalis were more attracted to infested Ife Brown than the uninfested (χ 2 = 5, df = 1, p = 0.0254). The results further showed that there were non-significant differences between the infested and uninfested grains of Ife BPC (χ 2 = 0.2, df = 1, p = 0.6547) and Oloyin (χ 2 = 3.2, df = 1, p = 0.0736) varieties. Conclusions Adult D. basalis reduced emergence of C maculatus and reduced damage in cowpea seeds. Olfactory cues played a necessary role in host-searching efforts of D. basalis.

Abstract Recolonization of predators to their former ranges is becoming increasingly prevalent. Such recolonization places predators among their prey once again; the latter having lived without predation (from such predators) for a considerable time. This renewed coexistence creates opportunities to explore predation ecology at both fundamental and applied levels. We used a paired experimental design to investigate white‐tailed deer risk allocation in the Upper and Lower Peninsulas (UP and LP) in Michigan, USA. Wolves are functionally absent in the LP, while deer in the UP coexist with a re‐established wolf population. We treated 15 sites each in UP and LP with wolf olfactory cues and observed deer vigilance, activity, and visitation rates at the interface of habitat covariates using remote cameras. Such a paired design across wolf versus no‐wolf areas allowed us to examine indirect predation effects while accounting for confounding parameters such as the presence of other predators and human activity. While wolf urine had no effect across most metrics in both UP and LP, we observed differences in deer activity in areas with versus without wolves. Sites treated with wolf urine in the UP showed a reduction in crepuscular deer activity, compared to control/novel‐scent treated sites. Furthermore, we observed a strong positive effect of vegetation cover on deer vigilance in these sites. This indicates that simulated predator cues likely affect deer vigilance more acutely in denser habitats, which presumably facilitates predation success. Such responses were however absent among deer in the LP that are presumably naïve toward wolf predation. Where human and non‐human predators hunt shared prey, such as in Michigan, predators may constrain human hunting success by increasing deer vigilance. Hunters may avoid such exploitative competition by choosing hunting/bait sites located in open areas. Our results pertaining to fundamental predation ecology have strong applied implications that can promote human–predator coexistence.

To better understand insect learning ability, demonstration of learning through conditioning is an effective research tool. Conditioning in social bees takes advantage of the proboscis extension reflex (PER) as a response to an unconditioned stimulus (US) (e.g., sucrose solution). The US is then associated with a conditioned stimulus (CS) (e.g., an odor) to elicit PER. However, solitary bees do not readily exhibit a PER when restrained and then prodded with an offering of sucrose. Managed solitary bees can be maintained in laboratory benchtop cages where they discover and feed from wicks soaked with aqueous sugar or honey. We sought to devise a protocol that demonstrates learning through simple conditioning for two managed solitary bees, Osmia lignaria and Megachile rotundata by exploiting their ability to locate a small feeder and reflexively extend the proboscis to retrieve a sucrose reward (US). In this study, the rewarded feeder was paired with a floral odor (CS) during training bouts. Newly emerged adult bees began training on the day of their emergence, continued training for another day, and were tested on the next day using a choice bioassay that revealed whether bees had learned the CS. The conditioning assay was effective for both bee species and sexes as revealed by proboscis extension towards material dosed with the reward-associated training odor. The ability to condition solitary bees could support important studies that address questions related to bee preferences for nesting and floral resources and for effects of pesticides or other stressors on learning and memory. [ABSTRACT FROM AUTHOR]

Flying insects are believed to rely primarily on visual cues for orientation, with chemical cues often being overlooked. In the case of solitary bees and wasps, being able to return successfully to their nests and provision their brood cells is paramount for the survival of the species. While vision has been shown to be involved in pinpointing the nest location, our results confirm that olfaction is important in nest recognition. The large diversity in nesting strategies observed among solitary Hymenoptera makes them an excellent model to comparatively study the use of olfactory cues from the nesting individual for nest recognition. We have analyzed the chemical profiles of three nesting bees (Osmia spp.) and one wasp (Sceliphron curvatum) and that of their nest entrances. A striking match in the identified chemicals was revealed between each nest and its occupant. When the chemicals were removed from the nest, a clear behavioral response could be observed for Osmia cornuta. This shows the importance of olfactory cues in complementing visual orientation for precise homing in a solitary species, thereby opening up various promising biological questions in the fields of sensory perception and complementation, or the trade-offs of nest aggregation and associated costs. [ABSTRACT FROM AUTHOR]

In this study, we examined the effect of synanthropic house mouse (Mus musculus) urine odor on catching probability of small mammals to live traps. We conducted a series of field experiments in August 2016 and 2017 in a natural forests of the northwestern Moscow Region (Russia). Small mammals were trapped at two 4-ha fields using capture-mark-recapture technique by setting 200 live traps (100 points, 2 traps per point) within each field. One trap in each pair was odorless (control) with bait only, whereas the other one was odor-baited with 20 μL of the urine of a synanthropic house mouse. Further analysis was based on the data collected from 2 rodent species (bank vole Myodes glareolus , herb field mouse Apodemus uralensis) and 3 shrew species (common shrew Sorex araneus , Laxmann's shrew Sorex caecutiens , and Eurasian pygmy shrew Sorex minutus). As a result, only bank voles significantly avoided odor-baited live traps. Using generalized linear mixed models, we showed that the choice of a trap by bank voles depended on their age, whereas the probability of repeated capture to a certain live trap was related to their prior experience. We discuss the possible role of components of synanthropic house mouse urine in the population management of exoanthropic small mammals. [ABSTRACT FROM AUTHOR]

Background: Cowpea seed beetle, Callosobruchus maculatus (L.) (Coleoptera: Chrysomelidae: Bruchinae), is the most important pest of stored cowpea in tropical regions. This study was designed to determine the presence of parasitoids associated with C. maculatus, investigate the efficacy of the parasitic wasp, Dinarmus basalis Rondani (Hymenoptera: Pteromalidae), in controlling C. maculatus as influenced by time and number of applications and ascertain the use of olfactory cues by D. basalis in host searching. Three markets in Ibadan, Southwest Nigeria, namely: Bodija, Mapo and Ojoo, were purposively surveyed for parasitoids associated with C. maculatus. Two pairs of D. basalis were released at 3-day intervals into cowpea seeds previously infested with C. maculatus. Treatments included: four times of parasitoid applications (4-TPA), three applications (3-TPA), two applications (2-TPA), 1 application (1-TPA) and a control without parasitoid application (0-TPA). All treatments were replicated four times in a completely randomized design to determine F1 progeny of C. maculatus and seed damage. Olfactory bioassay was carried out with D. basalis adults placed in a Y-tube olfactometer; and their preference for infested or uninfested three cowpea varieties, namely: Ife Brown, Ife BPC (Branching Peduncle) and Oloyin, as well as infested cowpea grains or pure air was evaluated. Results: Among the previously known parasitoids associated with C. maculatus, only D. basalis was found in the sampled markets. F1 progeny of adult C. maculatus reduced from 4.75 individuals (0-TPA) to 1.25 (2-TPA), 0.25 (3-TPA) and 0 (4-TPA). Concurrently, the number of exit holes on cowpea seeds significantly (p < 0.05) ranged from 5.25 (0-TPA) > 3.21 (1-TPA) > 2.20 (2-TPA) > 2.18 (4-RAP) > 1.39 (3-TPA). Adults D. basalis were more attracted to infested grains of Ife Brown (χ2 = 4, df = 1, p = 0.0455) and infested grains of Ife BPC (χ2 = 4, df = 1, p = 0.0455) than clean air. Similarly, adults D. basalis were more attracted to infested Ife Brown than the uninfested (χ2 = 5, df = 1, p = 0.0254). The results further showed that there were non-significant differences between the infested and uninfested grains of Ife BPC (χ2 = 0.2, df = 1, p = 0.6547) and Oloyin (χ2 = 3.2, df = 1, p = 0.0736) varieties. Conclusions: Adult D. basalis reduced emergence of C maculatus and reduced damage in cowpea seeds. Olfactory cues played a necessary role in host-searching efforts of D. basalis. [ABSTRACT FROM AUTHOR]

The mental association of perceived signals is a characteristic held by animals. Here, we examine whether Myrmica sabuleti, an ant belonging to a species with no particularly specialized morphological or anatomical features, and which can associate visual signals with a time of day, can also associate odors and time of day. Ants of two colonies collectively trained to thyme odor from 8 pm to 7 am and to lavender odor from 8 am to 7 pm reacted mostly to thyme when tested at 4 am and mostly to lavender when tested at 4 pm in the presence of the two odors. Ants of two other colonies trained to rosemary odor from 8 am to 7 pm and to orange zest odor from 8 pm to 7 am, when tested in front of the two odors, reacted essentially to rosemary at 4 pm and essentially to orange zest at 4 am. The ants have thus associated each odor with the time of the day when it was perceived during training. Two supplementary experiments showed that the weaker response to the odor which did not correspond to the time of the day of its training was not due to an aversion toward a less recently perceived cue. The ability to associate an odor with a particular time of the day could be advantageous for ants to select time periods for e.g., optimally and safely collecting food. [ABSTRACT FROM AUTHOR]

Butterflies use visual and olfactory cues to identify conspecifics during courtship. Tirumala limniace, Idea leuconoe, and Danaus chrysippus are three species of butterflies with a sympatric distribution, and T. limniace butterflies are rarely seen to chase I. leuconoe or D. chrysippus during courtship in artificial cultivation gardens, indicating that they have a mechanism for recognizing conspecifics; however, there are no reports on what kind of signals they use to recognize conspecifics. In this study, we investigated the cues used by T. limniace to identify conspecifics and the relative roles of visual and olfactory cues. We found that in the absence of olfactory cues (visual cues only), male and female butterflies were able to identify the same species based on wing color and pattern. By collecting and identifying body volatiles emitted from T. limniace males and females, we found that the highest amounts were β-ocimene and β-pinene, which were sourced from the insects' bodies (as opposed to sex pheromones). Furthermore, electroantennogram binding behavioral experiments showed that β-ocimene was involved in the process of species recognition and that the relative roles of olfactory cues were greater than those of visual cues at close range. Therefore, T. limniace males and females could utilize both visual and olfactory cues to identify conspecifics during courtship but preferred olfactory cues. The present study highlighted the important role of adult body odor rather than sex pheromones in butterfly species recognition. Significance statement: Butterflies use visual (wing color and pattern) and olfactory (sex pheromones) cues to identify conspecifics during courtship. Butterflies also release volatiles emitted from their bodies during courtship. However, there is no clear evidence that body volatiles (as opposed to sex pheromones) emitted from butterflies are involved in species recognition. We studied the functions of body volatiles emitted from Tirumala limniace adults and the relative roles of visual and olfactory cues in species recognition during courtship. We found that male and female adults could identify conspecifics using only visual cues. Meanwhile, we also found that the highest amounts of β-ocimene, which came from the bodies of T. limniace males and females, were also involved in the process of species recognition. The olfactory cues that butterflies use to identify conspecifics are usually sex pheromones, while the present study highlighted the important role of adult body odor rather than sex pheromones in butterfly species recognition. [ABSTRACT FROM AUTHOR]

Obtaining a suitable mate is an integral part of reproduction, with sexual selection processes such as female mate choice resulting in both direct and/or indirect benefits. Here, we investigated whether olfactory driven female mate choice influenced reproductive success in captive fat-tailed dunnarts (Sminthopsis crassicaudata). Although females spent 67% more time with a preferred male's scent, reproductive success was not influenced by assigned mate choice. Of the 10 (of 12) litters that survived to weaning, average litter size was higher for non-preferred pairings (3 ± 0.83) compared with preferred pairings (1.6 ± 0.60), with weaning success equal for both pairings. Analyses suggested that offspring sex ratios were influenced by mate choice, with females paired with their preferred mate having more daughters (81%) in comparison to non-preferred pairings (44%) and by paternal body condition, whereby females paired with males in better body condition produced more sons. In this species, altering offspring sex ratios in favour of daughters may be achieved by pairing with preferred males, and towards sons by pairing with males in better body condition. With the increasing need for captive breeding programs, these techniques may provide opportunities to correct sex ratio biases and incorporate natural mating systems into conservation programs. Incorporating natural mating behaviours, including female mate choice, has seen promising results, but is not yet common practice. Here, the incorporation of female mate choice into a fat-tailed dunnart (Sminthopsis crassicaudata) breeding program influenced sex ratio, aligning with the natural history of this species, but did not contribute to litter or weaning success. These findings emphasise the importance of understanding natural mating systems of species when managing captive breeding programs. Photograph by Brittney Gill. [ABSTRACT FROM AUTHOR]

Ant colonies have vast and diverse nutritional needs but forager ants have limited mobility to meet these needs. Forager ants would accrue significant energy savings if they were able to sense and orient toward odor plumes of both carbohydrate and protein food sources. Moreover, if worker ants, like other flightless insects, had reduced olfactory acuity, they would not recognize the specific odor signatures of diverse carbohydrate and protein sources, but they may be able to orient toward those odorants that are shared between (macronutrient) food sources. Using the Western carpenter ant, Camponotus modoc, as a model species, we tested the hypotheses that (1) food sources rich in carbohydrates (aphid honeydew, floral nectar) and rich in proteins (bird excreta, house mouse carrion, cow liver infested or not with fly maggots) all prompt long-distance, anemotactic attraction of worker ants, and (2) attraction of ants to plant inflorescences (fireweed, Chamaenerion angustifolium; thimbleberry, Rubus parviflorus; and hardhack, Spiraea douglasii) is mediated by shared floral odorants. In moving-air Y-tube olfactometer bioassays, ants were attracted to two of four carbohydrate sources (thimbleberry and fireweed), and one of four protein sources (bird excreta). Headspace volatiles of these three attractive sources were analyzed by gas chromatography-mass spectrometry, and synthetic odor blends of thimbleberry (7 components), fireweed (23 components), and bird excreta (38 components) were prepared. In Y-tube olfactometer bioassays, synthetic blends of thimbleberry and fireweed but not of bird excreta attracted ants, indicating that only the two floral blends contained all essential attractants. A blend of components shared between thimbleberry and fireweed was not attractive to ants. Our data support the conclusion that C. modoc worker ants can sense and orient toward both carbohydrate and protein food sources. As ants were selective in their responses to carbohydrate and protein resources, it seems that they can discern between specific food odor profiles and that they have good, rather than poor, olfactory acuity.

Autotomy is a drastic antipredator defense consisting of the voluntary shedding of a body part to escape from the predators. The loss of a body part may impair locomotion, feeding or mating, so animals may face a higher predation risk shortly after autotomy. Thus, until regeneration is completed, prey may adjust their behavior to reduce predation risk, and this could involve secondary costs. We assessed the effect of tail loss on the antipredator behavior of wall lizards (Podarcis muralis), comparing the behavior of tailed and tailless individuals exposed to a predatory snake (Coronella austriaca) scent, under controlled experimental conditions. Tailless lizards spent significantly more time performing behaviors with antipredatory significance (e.g., moving slowly), whereas tailed individuals performed exploratory walking for significantly more time. Moreover, tailless lizards spent more time basking, which probably increases the effectiveness of their cryptic design and decreases detection by predators. Lizards intensified the tongue flick rates when exposed to a pungent control or snake scents, as compared to their response to a neutral control. Besides, both tailed and tailless lizards intensified some aspects of their antipredator behavior (walking slowly and avoiding refuge use) when exposed to snake scent, which indicates discrimination of the smell of predatory snakes. Lizards decreased refuge use when exposed to predator scents, probably because the refuges are evaluated as unsafe due to a high concentration of snake scents. To conclude, our experiments showed that, after losing their tails, wall lizards modify their behavior in a way that likely minimizes predation risk. Highlights: Both tailed and tailless lizards intensified some aspects of their antipredator behavior when exposed to snake scents, which indicates discrimination of the smell of predatory snakes.Regardless of the presence of predator signals, tailless lizards, which have reduced defensive capabilities, spent more time performing behaviors with probable antipredatory significance, while tailed lizards performed exploratory movements for longer. [ABSTRACT FROM AUTHOR]

BACKGROUND Mosquitoes express different degrees of preference towards hosts depending on behavioral, ecological, and physiological factors. These preferences have implications for mosquito‐borne disease risk. This study investigated the effect of human blood groups on the behavior and fecundity of the female Aedes aegypti (Diptera: Culicidae) from March 2018 to August 2019. In laboratory tests, mosquitoes were fed artificial membrane feeders on A, AB, B, and O blood groups. The level of attraction to different blood groups was tested under controlled conditions with a wind tunnel bioassay. RESULTS: The responses of Ae. aegypti to the blood groups treatments in the five‐choice tunnel chambers showed a significant preference (Kruskal‐Wallis (2 = 85.772, df = 4, P < 0.0001) for favor blood group B. Also, the response of Ae. aegypti to olfactory cues (filth) derived from a pool of volunteers cutting across the blood groups showed a similar preference for pattern towards the blood group B. The percentage rate of digestibility in Ae. aegypti was highest in those fed on blood group O, while individuals fed on the AB blood group had the lowest digestion rate. Thus, the rate of digestibility highly varied significantly (P < 0.0001) between blood groups. Overall, Ae. aegypti fed on blood group B had the highest average feeding rate, number of females with eggs, and fecundity level, which showed a significant difference (P < 0.0001) on preferred. CONCLUSION: This study provides novel insight into the ABO host choice of Ae. aegypti and reinforces the need for personal protection against dengue virus transmission in light of the increased risk of exposure for individuals with B blood type. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Abstract Olfactory cues play an important role in mammalian biology, but have been challenging to assess in the field. Current methods pose problematic issues with sample storage and transportation, limiting our ability to connect chemical variation in scents with relevant ecological and behavioral contexts. Real‐time, in‐field analysis via portable gas chromatography–mass spectrometry (GC‐MS) has the potential to overcome these issues, but with trade‐offs of reduced sensitivity and compound mass range. We field‐tested the ability of portable GC‐MS to support two representative applications of chemical ecology research with a wild arboreal primate, common marmoset monkeys (Callithrix jacchus). We developed methods to (a) evaluate the chemical composition of marmoset scent marks deposited at feeding sites and (b) characterize the scent profiles of exudates eaten by marmosets. We successfully collected marmoset scent marks across several canopy heights, with the portable GC‐MS detecting known components of marmoset glandular secretions and differentiating these from in‐field controls. Likewise, variation in the chemical profile of scent marks demonstrated a significant correlation with marmoset feeding behavior, indicating these scents’ biological relevance. The portable GC‐MS also delineated species‐specific olfactory signatures of exudates fed on by marmosets. Despite the trade‐offs, portable GC‐MS represents a viable option for characterizing olfactory compounds used by wild mammals, yielding biologically relevant data. While the decision to adopt portable GC‐MS will likely depend on site‐ and project‐specific needs, our ability to conduct two example applications under relatively challenging field conditions bodes well for the versatility of in‐field GC‐MS.

This study examined the effect of perceived predation risk imposed by lynx (Lynx lynx) and wolf (Canis lupus) on red deer (Cervus elaphus) foraging behavior under experimental conditions. We hypothesized that in response to large carnivore scent red deer would increase their vigilance, although reducing the frequency and duration of visits to foraging sites. Consequently, browsing intensity on tree saplings was expected to decrease, whereas a higher proportion of more preferred species was expected to be browsed to compensate for higher foraging costs. We expected stronger responses towards the ambush predator lynx, compared with the cursorial predator wolf. These hypotheses were tested in a cafeteria experiment conducted within three red deer enclosures, each containing four experimental plots with olfactory cues of wolf, lynx, cow, and water as control. On each plot, a camera trap was placed and browsing intensity was measured for one consecutive week, repeated three times. Red deer reduced their visitation duration and browsing intensity on plots with large carnivore scent. Despite red deer showing a clear preference for certain tree species, the presence of large carnivore scent did not change selectivity towards different tree species. Contrary to our hypothesis, we found more pronounced effects of wolf (cursorial) compared with lynx (ambush). This study is the first to experimentally assess the perceived risk effects on the red deer foraging behavior of large carnivores differing in hunting modes. Our findings provide insights into the role of olfactory cues in predator–prey interactions and how they can modify fine-scale herbivore–plant interactions. In this study, we tested whether an ambush (lynx) and a pursuit (wolf) predator influenced behavior and food selection of a large herbivore. We experimentally showed that under perceived predation risk of both lynx and wolf, the large herbivore reduced visitation time, altered visitation duration, and reduced food intake. Differences in behavior and food intake under perceived predation risk of both predators suggests more pronounced risk effects from the pursuit predator. [ABSTRACT FROM AUTHOR]

When people meet a potential partner for the first time, they are confronted with multiple sources of information, encompassing different modalities, that they can use to determine whether this partner is suitable for them or not. While visual attractiveness has widely been studied with regard to partner choice, olfactory and auditory cues have received less attention, even though they might influence the attitudes that people have towards their partner. Therefore, in this study, we employed a combination of pre-date multimodal rating tasks followed by speed-date sessions. This offered a naturalistic setup to study partner choice and disentangle the relative effects of a priori attractiveness ratings of sight, scent and sound on date success. Visual attractiveness ratings showed a strong positive correlation with propensity to meet the partner again, while the effects of olfactory and auditory attractiveness were negligible or not robust. Furthermore, we found no robust sex differences in the importance of the three modalities. Our findings underscore the relative importance of visual attractiveness in initial mate choice, but do not corroborate the idea that static pre-date measures of auditory and olfactory attractiveness can predict first date outcomes. [ABSTRACT FROM AUTHOR]

The effect of environmental enrichment on the behavior and welfare in captivity of reptiles and of freshwater turtles in particular, which are popular aquarium and pet species, is very little studied compared to other taxa. We carried out a small scale case‐study on the effect of colored object enrichment, with and without fish scent, on the behavior of a group of 15 cooters (Pseudemys sp.) and sliders (Trachemys scripta ssp.) on display at a public aquarium. The new enrichment aimed to reduce the escape behavior (interaction with transparent boundaries) and increase exploration and random swimming. We used simultaneous recording of behavior at whole group level and for focal individually‐marked turtles. The escape behavior decreased on days with new enrichment before feeding at whole group level and for the focal turtles overall, in spite of the relatively low interest in the colored objects. Fish‐scented objects attracted significantly more interest. Random swimming, enrichment focus, aggression and submission increased significantly, and basking decreased significantly at whole group level before feeding, with smaller differences after feeding. There were large differences between individual turtles with respect to activity budgets and changes in behavior on days with new enrichment, with both increases and decreases seen in escape behavior, aggression, and levels of activity. Our outcomes suggested that introducing new colored objects with food scent may be beneficial for reducing escape behavior in captive freshwater turtles. However, careful monitoring of effects at individual level and much larger scale investigations, including postenrichment periods, are needed. Research Highlights: The presence of colored objects reduced the escape behavior of freshwater turtles, mainly before feeding.There was more interest when the new objects were fish‐scented.There were differences in behavior and response to enrichment at individual level. [ABSTRACT FROM AUTHOR]

Vector control is an important component of the interventions aimed at mosquito‐borne disease control. Current and future mosquito control strategies are likely to rely largely on the understanding of the behavior of the vector, by exploiting mosquito biology and behavior, while using cost‐effective, carefully timed larvicidal and high‐impact, low‐volume adulticidal applications. Here we review the knowledge on the ecology of mosquito oviposition behavior with emphasis on the potential role of infochemicals in surveillance and control of mosquito‐borne diseases. A search of PubMed, Embase, Web of Science, Global Health Archive, and Google Scholar databases was conducted using the keywords mosquito, infochemical, pheromone, kairomone, allomone, synomone, apneumone, attractant, host‐seeking, and oviposition. Articles in English from 1974 to 2019 were reviewed to gain comprehensive understanding of current knowledge on infochemicals in mosquito resource‐searching behavior. Oviposition of many mosquito species is mediated by infochemicals that comprise pheromones, kairomones, synomones, allomones, and apneumones. The novel putative infochemicals that mediate oviposition in the mosquito subfamilies Anophelinae and Culicinae were identified. The role of infochemicals in surveillance and control of these and other mosquito tribes is discussed with respect to origin of the chemical cues and how these affect gravid mosquitoes. Oviposition attractants and deterrents can potentially be used for manipulation of mosquito behavior by making protected resources unsuitable for mosquitoes (push) while luring them towards attractive sources (pull). In this review, strategies of targeting breeding sites with environmentally friendly larvicides with the aim to develop appropriate trap‐and‐kill techniques are discussed. [ABSTRACT FROM AUTHOR]

Male olfactory cues may guide aggregation on spawning reefs, mate evaluation and synchronized gamete release in lake trout Salvelinus namaycush, but a lack of information on the source and identity of the cues precludes direct tests of their function. Using a two‐channel flume, we found ovulated female lake trout increased time spent in the channel treated with spermiated male‐conditioned water, urine and bile but not synthesized prostaglandin F2α. We suggest future efforts to characterize male olfactory cues focus on urine and postulate that bile acids contribute to its behavioural activity. [ABSTRACT FROM AUTHOR]

Male olfactory cues may guide aggregation on spawning reefs, mate evaluation and synchronized gamete release in lake trout Salvelinus namaycush, but a lack of information on the source and identity of the cues precludes direct tests of their function. Using a two‐channel flume, we found ovulated female lake trout increased time spent in the channel treated with spermiated male‐conditioned water, urine and bile but not synthesized prostaglandin F2α. We suggest future efforts to characterize male olfactory cues focus on urine and postulate that bile acids contribute to its behavioural activity. [ABSTRACT FROM AUTHOR]

People interact with computers using their senses. Currently, in a digital context, traditional digital media like videos and images used to convey information to users, and these media can be used as a source of information. However, relatively few studies have been conducted on olfactory media as a source of information in a digital context. In this paper, we report on a study that examined the possibility of using olfactory media as a source of information and whether its usage as informational cues enhances learning performance and user Quality of Experience (QoE). To this end, an olfactory-enhanced quiz (web-based) was developed about four countries. The quiz contained different types of questions employing four types of digital media in their contents: text, image, audio and olfactory media. Four scents were used that were considered to be related to the respective countries. Sixty-four participants were invited to our experiment to evaluate this application. Our results revealed that usage of olfactory media synchronised with traditional digital media had a significant impact on learner performance compared to the case when no olfactory media was employed. In respect of user QoE, it was found that olfactory media influenced users positively; moreover, they were passionate about engaging with enhanced olfactory applications in the future. [ABSTRACT FROM AUTHOR]

The mutualism between chemical cues emitted into the air and variations in how primates respond to them using olfaction has demonstrated aspects of species‐specific adaptations. Building on this mutualism we can look at particle deposition as another means to understanding how various environments may have elicited biological changes that enable efficient communication. Research on particle movement and deposition within the nasal cavity is largely based on questions about health as it relates to drug delivery systems and overall olfactory function in modern humans. With increased access to 3D models and the use of computational fluid dynamic analysis, researchers have been able to simulate site‐specific deposition, to determine what particles are making it through the nasal cavity to the main olfactory epithelium, which ultimately leads to processing in the olfactory bulb. Here we discuss particle deposition research, sensory drive and their potential applications to evolutionary anthropology. [ABSTRACT FROM AUTHOR]

Olfactory cues play an important role in mammalian biology, but have been challenging to assess in the field. Current methods pose problematic issues with sample storage and transportation, limiting our ability to connect chemical variation in scents with relevant ecological and behavioral contexts. Real‐time, in‐field analysis via portable gas chromatography–mass spectrometry (GC‐MS) has the potential to overcome these issues, but with trade‐offs of reduced sensitivity and compound mass range. We field‐tested the ability of portable GC‐MS to support two representative applications of chemical ecology research with a wild arboreal primate, common marmoset monkeys (Callithrix jacchus). We developed methods to (a) evaluate the chemical composition of marmoset scent marks deposited at feeding sites and (b) characterize the scent profiles of exudates eaten by marmosets. We successfully collected marmoset scent marks across several canopy heights, with the portable GC‐MS detecting known components of marmoset glandular secretions and differentiating these from in‐field controls. Likewise, variation in the chemical profile of scent marks demonstrated a significant correlation with marmoset feeding behavior, indicating these scents' biological relevance. The portable GC‐MS also delineated species‐specific olfactory signatures of exudates fed on by marmosets. Despite the trade‐offs, portable GC‐MS represents a viable option for characterizing olfactory compounds used by wild mammals, yielding biologically relevant data. While the decision to adopt portable GC‐MS will likely depend on site‐ and project‐specific needs, our ability to conduct two example applications under relatively challenging field conditions bodes well for the versatility of in‐field GC‐MS. [ABSTRACT FROM AUTHOR]

1. Although associative learning is widespread across animals, its ecological importance is difficult to assess because learning is rarely studied in the field, where informative cues are juxtaposed against complex backgrounds of uninformative noise. 2. Ants rely heavily on chemical cues for foraging and engage in many ecologically important interactions with plants. Nevertheless, little is known about the role of associative learning of plant chemicals in ant foraging for carbohydrates. 3. In a field setting, the present study investigated whether the distantly related ant species Formica podzolica (Formicinae subfamily) and Tapinoma sessile (Dolichoderinae subfamily) exhibited associative learning of the chemical cues from two co‐occurring plant species that are taxonomically and chemically distinct (Asteraceae: Helianthella quinquenervis and Apiaceae: Ligusticum porteri). 4. For two consecutive summers, ants were trained to forage from artificial sugar‐rich baits associated with the leaf chemicals from either H. quinquenervis or L. porteri for 24 h, after which a two‐choice test was deployed to assess whether ants would be more likely to select baits associated with the same (versus different) plant chemicals on which they had been trained. 5. The present study demonstrates associative learning of chemicals from both plant species, and these effects were consistent between ant species and years; training increased bait occupancy from 42% on the untrained scent to 66% on the trained scent. These results indicate that associative odour‐learning may be widespread across ants and serve as an important mechanism mediating ant selection of resources. [ABSTRACT FROM AUTHOR]

Ambrosia beetles exhibit broad host ranges but a narrow preference based on the condition of the host. Tissues infected by pathogens or containing ethanol can facilitate attacks by ambrosia beetles, although it still remains unclear how these factors interact.The present study aimed to examine how (i) chestnut logs infected with the fungal pathogen Cryphonectria parasitica and treated with ethanol (i.e. baited with ethanol lure, soaked in ethanol or untreated) and (ii) hornbeam logs soaked in different ethanol concentrations (3–12.5%) affect host selection and colonization success of ambrosia beetles.Ethanol‐soaked logs were more attractive to Anisandrus dispar than ethanol‐baited logs or untreated logs, although this difference was more evident in uninfected than infected logs. Increasing ethanol concentration in host tissues was differentially attractive to Xyleborinus saxesenii and Xylosandrus germanus. A nonlinear relationship was also documented between ethanol concentration and emergence of X. germanus adults.Overall, the results obtained suggest that the presence of C. parasitica in chestnut logs can affect host selection in ambrosia beetles. In addition, the ethanol concentration in tree tissues affects host selection and colonization success, although the effect varies depending on the beetle species. This contrasting response could be a niche‐partitioning mechanism based on ethanol within host tissues. [ABSTRACT FROM AUTHOR]

There is increasing evidence that plant-associated microorganisms play important roles in shaping interactions between plants and insect herbivores. Studies of both pathogenic and beneficial plant microbes have documented wide-ranging effects on herbivore behavior and performance. Some studies, for example, have reported enhanced insect-repellent traits or reduced performance of herbivores on microbe-associated plants, while others have documented increased herbivore attraction or performance. Insect herbivores frequently rely on plant cues during foraging and oviposition, suggesting that plant-associated microbes affecting these cues can indirectly influence herbivore preference. We review and synthesize recent literature to provide new insights into the ways pathogenic and beneficial plant-associated microbes alter visual, olfactory, and gustatory cues of plants that affect host-plant selection by insect herbivores. We discuss the underlying mechanisms, ecological implications, and future directions for studies of plant-microbial symbionts that indirectly influence herbivore behavior by altering plant traits. [ABSTRACT FROM AUTHOR]

• Cucurbit crops are dependent on animal pollinators for their fruit formation. • Cucurbit flowers are attractive to both pollinators and antagonistic florivores. • Bees, moths and beetles are frequent visitors of the colorful and scented flowers. • Carotenoids are responsible for floral colours and various volatiles for the scents. • Candidates for genes forming cucurbit floral scents and pigments are summarized. Fruiting of most cucurbits, among them several commercially used species, relies on animals that transfer pollen from male to female flowers. To attract their pollinators, many cucurbits produce large, colorful and scented flowers, which, however, also attract florivores. Knowing the flower visitors and understanding the specific signals, including their biosynthesis, attractive to pollinators and florivores might be useful when aiming to increase pollination and fruiting by ecological measures, breeding and genetic engineering. This review summarizes the knowledge available on floral pigments, scents and visitors of cucurbits. We also review the genetic basis of floral pigment and scent production as well as the role of floral colors and scents in attracting pollinators and florivores. Floral visitors and colors are quite well studied, but there is very limited knowledge on the biosynthesis of the various floral scent compounds described and the cues used by the different flower visitors to find cucurbit flowers. [ABSTRACT FROM AUTHOR]

Social bees can deposit specialized glandular secretions, or signals, that allow foragers to revisit rewarding and to avoid unrewarding food sources. However, it is not known if bees can orient towards olfactory cues such as excreta deposited near food sources. We report that Melipona mandacaia foragers (stingless bees) deposit an odor cue, anal droplets, and a previously undescribed ventro-abdominal odor on food sources. Surprisingly, foragers deposited attractive odor marks on good food sources to which they recruited and on poor food sources to which they did not recruit. Foragers left the most anal droplets on dilute food sources to which they did not recruit (1.25-M sucrose solution), yet returning foragers were attracted to anal droplets obtained on poor food sources and presented in bioassays. Foragers were attracted to ventro-abdominal odors obtained on good food sources (2.5-M sucrose solution). Chemical extractions suggest that odor marks contain attractive polar compounds. We also provide the first detailed description of forager waggling and spinning behavior on poor and good food sources. Waggling may be a method of dispersing anal droplets and spinning may help foragers learn local landmarks.

The Dipteran family Tephritidae (true fruit flies) comprises more than 5000 species classified in 500 genera distributed worldwide. Tephritidae include devastating agricultural pests and highly invasive species whose spread is currently facilitated by globalization, international trade and human mobility. The ability to identify and exploit a wide range of host plants for oviposition, as well as effective and diversified reproductive strategies, are among the key features supporting tephritid biological success. Intraspecific communication involves the exchange of a complex set of sensory cues that are species- and sex-specific. Chemical signals, which are standing out in tephritid communication, comprise long-distance pheromones emitted by one or both sexes, cuticular hydrocarbons with limited volatility deposited on the surrounding substrate or on the insect body regulating medium- to short-distance communication, and host-marking compounds deposited on the fruit after oviposition. In this review, the current knowledge on tephritid chemical communication was analysed with a special emphasis on fruit fly pest species belonging to the Anastrepha, Bactrocera, Ceratitis, Rhagoletis and Zeugodacus genera. The multidisciplinary approaches adopted for characterising tephritid semiochemicals, and the real-world applications and challenges for Integrated Pest Management (IPM) and biological control strategies are critically discussed. Future perspectives for targeted research on fruit fly chemical communication are highlighted.