Predatory Strategies Research Articles

When ancestry haunts – can evolutionary links to ancestors affect vulnerability of Australian prey to introduced predators? A preliminary study

The high extinction risk of Australian marsupials has been attributed to their failure to recognise novel predators, the application of inappropriate antipredator responses, and advanced hunting strategies of novel predators. This study is a preliminary attempt to explore whether the Lumholtz’ tree-kangaroo (Dendrolagus lumholtzi) (a) is able to recognise odour cues from different predators as threats, and (b) possesses predator-archetype specific antipredator responses. A small number of available captive tree-kangaroos were exposed to faecal odours from two extant predators of different archetypes (python, dingo), a regionally extinct predator which closely matches past terrestrial predators (Tasmanian devil), and a novel predator (domestic dog). Lavender oil was used as non-predator novel odour and water as control. Results suggest that all subjects associated the presented odours with a threat, albeit to different degrees, but did not display predator-archetype specific responses. It appears that this species applies an ancestral antipredator response of flight-on-the ground when encountering predators, including novel predators. Although the results need to be confirmed with more animals, further studies on the vulnerability of Australian prey to novel predators should take the ancestral history of Australian prey species into account.

Strike-Induced Chemosensory Searching in Reptiles: A Review

Chemosensory searching in squamates with specialized tongue–vomeronasal systems is well-documented. By tongue-flicking, these reptiles gather important chemical cues from their environment to guide their feeding behavior. Strike-induced chemosensory searching (SICS) is a specific expression of chemosensory reception that is central to the predatory strategy used by venomous reptiles that strike, release, and relocate their prey. This complex behavioral process consists of multiple sequential steps and has been mainly studied in viperids, particularly rattlesnakes. Although this phenomenon has been extensively researched, there is no comprehensive review of the SICS literature. Here, we provide such a review, centered on the idea that SICS is a result of suppression, and then enhancement, of chemosensory searching that serves as a key element of the ambush hunting strategy that most viperid snakes use to consume large and well-defended prey. SICS is also present in other venomous and nonvenomous taxa, and we include a taxonomic categorization of SICS studies in our review. We summarize the key findings discovered during decades of research into this remarkable feeding behavior and highlight areas where our knowledge remains incomplete in an effort to foster further research that will increase our understanding of reptilian feeding ecology.

Pursuit and Evasion Strategies in the Predator-Prey Interactions of Fishes.

Predator-prey interactions are critical to the biology of a diversity of animals. Although prey capture is determined by the direction, velocity, and timing of motion by both animals, it is generally unclear what strategies are employed by predators and prey to guide locomotion. Here we review our research on fishes that tests the pursuit strategy of predators and the evasion strategy of prey through kinematic measurements and agent-based models. This work demonstrates that fish predators track prey with variations on a deviated-pursuit strategy that is guided by visual cues. Fish prey employ a mixed strategy that varies with factors such as the direction of a predator's approach. Our models consider the stochastic nature of interactions by incorporating measured probability distributions to accurately predict measurements of survivorship. A sensitivity analysis of these models shows the importance of the response distance of prey to their survival. Collectively, this work demonstrates how strategy affects the outcome of predator-prey interactions and articulates the roles of sensing, control, and propulsion. The research program that we have developed has the potential to offer a framework for the study of strategy in the predator-prey interactions of a variety of animals.

New evidence of a fish–bird interspecific feeding association between the European seabass and the European shag in the Mediterranean Sea

Although they have received little attention, interspecific feeding associations are a particular predation behavior in which two or more different species temporary feed simultaneously on the same food sources to obtain greater success in predation. These collaborations can be either mutualistic, commensalistic, or parasitic. One of the best-known examples is the seabird–cetacean associations. Prey herding is the foraging tactic most used in these associations and consists of swimming around and under prey balls to trap them in the water column. Here we reported some new evidence of a fish–bird interspecific feeding association between the European seabass, Dicentrarchus labrax (Linnaeus, 1758) and the European shag, Gulosus aristotelis (Linnaeus, 1761). We analyzed this association through the photograph and video documentation provided by “citizen scientists” in the Mediterranean Sea. We collected reliable proofs of this behavior, at least, in three instances from observations made by recreational fishermen in the Kvarner bay (Croatia, North Adriatic Sea). From the photographs and videos made available, we attempted to reconstruct a predation strategy adopted by these associated species to better understand the advantage this provides during hunting. Although it is not yet clear whether this association is an opportunistic behavior of the European seabass or a mutualistic strategy used by both species to improve their catching success, this feeding association seems to increase the chances to defeat prey defense strategies. Notably, some behavioral imitation of hunting strategies may be put in place by seabasses, which often feed in association with dolphins and other birds using similar prey herding strategies.

Insights into Bdellovibrio spp. mechanisms of action and potential applications

Recent studies investigating Bdellovibrio spp. have found that although this predator predominantly preys on Gram-negative organisms, under certain conditions (nutrient/prey limitation), it will adapt to survive and grow axenically (without prey) or in the presence of Gram-positive bacterial prey. These advances in the understanding of predatory bacteria have stimulated a renewed interest in these organisms and the potential applications of Bdellovibriospp. to the benefit of society. Early studies primarily focused on the application of predatory bacteria as "live antibiotics" in the medical field, probiotics in aquaculture and veterinary medicine and their use in agriculture. Additionally, studies have investigated their prevalence in wastewater and environmental sources. However, comprehending that Bdellovibrio spp. may also prey on and target Gram-positive organisms, implies that these predators could specifically be applied for the bioremediation or removal of mixed bacterial communities. Recent studies have also indicated that Bdellovibrio spp. may be useful in controlling food spoilage organisms and subsequently decrease our reliance on food additives. This review will thus highlight recent developments in understanding Bdellovibriospp. predation strategies and focus on potential new applications of these organisms for water treatment, food preservation, enhancement of industrial processes, and in combination therapies with bacteriophages and/or antibiotics to combat multi-drug resistant organisms.

Reforestations of Tropical Forests Alter Interactions Between Web-Building Spiders and Their Prey

Immense effort has been devoted to mitigating the negative effect of deforestation, one of the main factors causing global change. However, the effect of reforestation management on food-webs has been rarely studied and no study so far has investigated the effect on predator–prey interactions in forest understories. We studied predator–prey interactions in forest understories using web-building spiders in four forest types: dry evergreen forest representing a natural control and three 20–30-year-old reforestation types, namely secondary naturally regenerating dry evergreen forest, monoculture reforestation dominated by Eucalyptus camaldulensis, and mixture reforestation dominated by Acacia mangium and E. camaldulensis. We collected spiders with their prey and measured the availability of potential prey. We also measured different spider traits (web type, body size) that can be selected by various forest types and consequently affect the predator–prey interactions. The forest type influenced the predator–prey interaction in a complex way, interactively affecting spider density and prey-specific capture efficacy of spider community. The forest type also influenced the web-type and body-size distributions of spiders. Surprisingly, the prey composition caught by spider webs was related only to the web-type but not to the spider mean body size. None of the studied reforestations have yet restored the natural predator–prey interactions, which indicates that conservation management in the tropics should focus on establishing protected areas in pristine regions instead of relying on reforestation. Moreover, the food-web models need to incorporate not only body sizes but also hunting strategies of predators to improve their predictive abilities.

Spatial and temporal variability in the diet of Pacific marten (Martes caurina) on Haida Gwaii: an apex predator in a highly modified ecosystem

Knowledge of the diet ecology of apex predators in insular island ecosystems has direct applications to the conservation of endemic species at risk of extinction. We used stable isotopes of carbon and nitrogen to infer resource-use strategies of an indigenous predator, the Pacific marten (Martes caurina (Merriam, 1890)), in a highly modified ecosystem on Haida Gwaii, British Columbia, Canada. We used Bayesian isotopic mixing models to estimate the relative contributions of different food sources to marten diet across seasons and during overall lifetime, and to determine how diet varied with different levels of access to marine resources. Isotopes of carbon and nitrogen measured in hair and muscle tissue suggested that marten consumed salmon (3%–17%) and berries (25%–37%) seasonally; these diet groups were relatively minor components of the lifetime diet. Analysis of bone collagen suggested that terrestrial fauna — including birds, deer, small mammals, and invertebrates — contributed the most to diet (41%–55%), and marine invertebrates (38%–48%), not salmon (0%–3%), were the main allochthonous marine nutrient subsidy to lifetime diet. Plasticity in foraging ecology, combined with a broad dietary niche, introduced prey, notably the invasive Sitka black-tailed deer (Odocoileus hemionus sitkensis Merriam, 1898), as well as abundant marine resources, may allow marten to outcompete other indigenous and endemic carnivores on Haida Gwaii.

A band selection approach based on wavelet support vector machine ensemble model and membrane whale optimization algorithm for hyperspectral image

Hyperspectral Image (HSI) has become one of the important remote sensing sources for object interpretation by its abundant band information. Among them, band selection is considered as the main theme in HSI classification to reduce the data dimension, and it is a combinatorial optimization problem and difficult to be completely solved by previous techniques. Whale Optimization Algorithm (WOA) is a newly proposed swarm intelligence algorithm that imitates the predatory strategy of humpback whales, and membrane computing is able to decompose the band information into a series of elementary membranes that decreases the coding length. In addition, Support Vector Machine (SVM) combined with wavelet kernel is adapted to HSI datasets with high dimension and small samples, ensemble learning is an effective tool that synthesizes multiple sub-classifiers to solve the same problem and obtains accurate category label for each sample. In the paper, a band selection approach based on wavelet SVM (WSVM) ensemble model and membrane WOA (MWOA) is proposed, experimental results indicate that the proposed HSI classification technique is superior to other corresponding and newly proposed methods, achieves the optimal band subset with a fast convergence speed, and the overall classification accuracy has reached 93% for HSIs.

Concentrations and stable isotopes of mercury in sharks of the Galapagos Marine Reserve: Human health concerns and feeding patterns

The human ingestion of mercury (Hg) from sea food is of big concern worldwide due to adverse health effects, and more specifically if shark consumption constitutes a regular part of the human diet. In this study, the total mercury (THg) concentration in muscle tissue were determined in six sympatric shark species found in a fishing vessel seized in the Galapagos Marine Reserve in 2017. The THg concentrations in shark muscle samples (n = 73) varied from 0.73 mg kg-1 in bigeye thresher sharks (Alopias superciliosus) to 8.29 mg kg-1 in silky sharks (Carcharhinus falciformis). A typical pattern of Hg bioaccumulation was observed for all shark species, with significant correlation between THg concentration and shark size for bigeye thresher sharks, pelagic thresher sharks (Alopias pelagicus) and silky sharks. Regarding human health concerns, the THg mean concentration exceeded the maximum weekly intake fish serving in all the studied species. Mass-Dependent Fractionation (MDF, δ202Hg values) and Mass-Independent Fractionation (MIF, Δ199Hg values) of Hg in whitetip sharks (Carcharhinus longimanus) and silky sharks, ranged from 0.70‰ to 1.08‰, and from 1.97‰ to 2.89‰, respectively. These high values suggest that both species are feeding in the epipelagic zone (i.e. upper 200 m of the water column). While, blue sharks (Prionace glauca), scalloped hammerhead sharks (Shyrna lewini) and thresher sharks were characterized by lower Δ199Hg and δ202Hg values, indicating that these species may focus their foraging behavior on prey of mesopelagic zone (i.e. between 200 and 1000 m depth). In conclusion, the determination of THg concentration provides straight-forward evidence of the human health risks associated with shark consumption, while mercury isotopic compositions constitute a powerful tool to trace the foraging strategies of these marine predators. CapsuleA double approach combining Hg concentrations with stable isotopes ratios allowed to assess ontogeny in common shark species in the area of the Galapagos Marine Reserve and the human health risks concern associated to their consumption.

Biomechanics of juvenile tyrannosaurid mandibles and their implications for bite force: Evolutionary biology.

The tyrannosaurids are among the most well-studied dinosaurs described by science, and analysis of their feeding biomechanics allows for comparison between established tyrannosaurid genera and across ontogeny. 3D finite element analysis (FEA) was used to model and quantify the mechanical properties of the mandibles (lower jaws) of three tyrannosaurine tyrannosaurids of different sizes. To increase evolutionary scope and context for 3D tyrannosaurine results, a broader sample of validated 2D mandible FEA enabled comparisons between ontogenetic stages of Tyrannosaurus rex and other large theropods. It was found that mandibles of small juvenile and large subadult tyrannosaurs experienced lower stress overall because muscle forces were relatively lower, but experienced greater simulated stresses at decreasing sizes when specimen muscle force is normalized. The strain on post-dentary ligaments decreases stress and strain in the posterior region of the dentary and where teeth impacted food. Tension from the lateral insertion of the looping m. ventral pterygoid muscle increases compressive stress on the angular but may decrease anterior bending stress on the mandible. Low mid-mandible bending stresses are congruent with ultra-robust teeth and high anterior bite force in adult T. rex. Mandible strength increases with size through ontogeny in T. rex and phylogenetically among other tyrannosaurids, in addition to that tyrannosaurid mandibles exceed the mandible strength of other theropods at equivalent ramus length. These results may indicate separate predatory strategies used by juvenile and mature tyrannosaurids; juvenile tyrannosaurids lacked the bone-crunching bite of adult specimens and hunted smaller prey, while adult tyrannosaurids fed on larger prey.

Diet Diversity in Carnivorous Terebrid Snails Is Tied to the Presence and Absence of a Venom Gland

Predator-prey interactions are thought to play a driving role in animal evolution, especially for groups that have developed venom as their predatory strategy. However, how the diet of venomous animals influences the composition of venom arsenals remains uncertain. Two prevailing hypotheses to explain the relationship between diet and venom composition focus on prey preference and the types of compounds in venom, and a positive correlation between dietary breadth and the number of compounds in venom. Here, we examined venom complexity, phylogenetic relationship, collection depth, and biogeography of the Terebridae (auger snails) to determine if repeated innovations in terebrid foregut anatomy and venom composition correspond to diet variation. We performed the first molecular study of the diet of terebrid marine snails by metabarcoding the gut content of 71 terebrid specimens from 17 species. Our results suggest that the presence or absence of a venom gland is strongly correlated with dietary breadth. Specifically, terebrid species without a venom gland displayed greater diversity in their diet. Additionally, we propose a revision of the definition of venom complexity in conoidean snails to more accurately capture the breadth of ecological influences. These findings suggest that prey diet is an important factor in terebrid venom evolution and diversification and further investigations of other understudied organisms, like terebrids, are needed to develop robust hypotheses in this area.

Individuality counts: A new comprehensive approach to foraging strategies of a tropical marine predator

Foraging strategies are of great ecological interest, as they have a strong impact on the fitness of an individual and can affect its ability to cope with a changing environment. Recent studies on foraging strategies show a higher complexity than previously thought due to intraspecific variability. To reliably identify foraging strategies and describe the different foraging niches they allow individual animals to realize, high-resolution multivariate approaches which consider individual variation are required. Here we dive into the foraging strategies of Galápagos sea lions (Zalophus wollebaeki), a tropical predator confronted with substantial annual variation in sea surface temperature. This affects prey abundance, and El Niño events, expected to become more frequent and severe with climate change, are known to have dramatic effects on sea lions. This study used high-resolution measures of depth, GPS position and acceleration collected from 39 lactating sea lion females to analyze their foraging strategies at an unprecedented level of detail using a novel combination of automated broken stick algorithm, hierarchical cluster analysis and individually fitted multivariate hidden Markov models. We found three distinct foraging strategies (pelagic, benthic, and night divers), which differed in their horizontal, vertical and temporal distribution, most likely corresponding to different prey species, and allowed us to formulate hypotheses with regard to adaptive values under different environmental scenarios. We demonstrate the advantages of our multivariate approach and inclusion of individual variation to reliably gain a deeper understanding of the adaptive value and ecological relevance of foraging strategies of marine predators in dynamic environments.

THE INFLUENCE OF COVID-19 ON THE SPIRITUAL WORLD OF STUDENTS FORMATION IN THE CONDITIONS OF GLOBALIZATION CRISIS

The article highlights the main transformation processes of the modern world – the transition to a new civilizational structure as an informational and globalization processes that unfolded at the end of the twentieth century. The main approaches to understanding the essence and main directions of globalization are characterized in a concentrated concise form. It is noted that the theoretical concepts of this process considered the desire of the subjective factor, and natural factors were not predicted. This one-sidedness in explaining globalization was perceived only when a "pitfall" – Covid -19 – arose in this process.Covid-19 is explained as a natural pathogen, as a global "quantum" of negative impact on the sphere of material and spiritual production. The concept of "quantum" in the article is used to research and understand the basis of most medical macros. It is indicated that such "quanta" in the history of mankind were epidemics, diseases, today Covid -19, arising from the predatory strategy of environmental management. Revealed its destructive impact on the spiritual life of society, its basic component of education. In the context of this goal, the main directions of the crisis that is emerging now are revealed. Objective substantiation is attributed to them and received: a decrease in the level of personal knowledge; decline in the practical training of future specialists, due to the transition to distance learning. Attention is focused on the complexity of the formation for a worldview through the termination of the connection between the teacher and the student. The problems with the formation of the mentality are characterized, the essence of the mental field is explained, its components are highlighted. The statement of the problem of the relationship between education and morality is emphasized.

Attacks of songbirds in mixed‐species flocks by Eurasian Sparrowhawks: strategies of predators and potential prey

Attacks of songbirds in mixed‐species flocks by Eurasian Sparrowhawks: strategies of predators and potential prey

Arthropod Intelligence? The Case for Portia.

Macphail’s “null hypothesis,” that there are no differences in intelligence, qualitative, or quantitative, between non-human vertebrates has been controversial. This controversy can be useful if it encourages interest in acquiring a detailed understanding of how non-human animals express flexible problem-solving capacity (“intelligence”), but limiting the discussion to vertebrates is too arbitrary. As an example, we focus here on Portia, a spider with an especially intricate predatory strategy and a preference for other spiders as prey. We review research on pre-planned detours, expectancy violation, and a capacity to solve confinement problems where, in each of these three contexts, there is experimental evidence of innate cognitive capacities and reliance on internal representation. These cognitive capacities are related to, but not identical to, intelligence. When discussing intelligence, as when discussing cognition, it is more useful to envisage a continuum instead of something that is simply present or not; in other words, a continuum pertaining to flexible problem-solving capacity for “intelligence” and a continuum pertaining to reliance on internal representation for “cognition.” When envisaging a continuum pertaining to intelligence, Daniel Dennett’s notion of four Creatures (Darwinian, Skinnerian, Popperian, and Gregorian) is of interest, with the distinction between Skinnerian and Popperian Creatures being especially relevant when considering Portia. When we consider these distinctions, a case can be made for Portia being a Popperian Creature. Like Skinnerian Creatures, Popperian Creatures express flexible problem solving capacity, but the manner in which this capacity is expressed by Popperian Creatures is more distinctively cognitive.

Battle of the Large Carnivores: Spatial Partitioning in a Small, Enclosed Reserve?

Interspecific competition among terrestrial carnivores can have widespread impacts on community structure and can ultimately determine which species are able to coexist. Within the carnivore guild, coexistence can be achieved through either spatial, temporal or dietary partitioning. The most effective method of avoiding competition may be spatial partitioning, as it removes the potential for negative interactions. The ways in which large carnivore species utilize and partition space in small, enclosed reserves in South Africa is currently poorly understood. This knowledge gap weakens our understanding of which mechanisms structure large carnivore communities in these systems. Thus, our aim was to use Global Positioning System (GPS) collars to investigate the spatial dynamics of large carnivores [four lions (Panthera leo), three leopards (Panthera pardus) and three spotted hyaenas (Crocuta crocuta)] on a small, enclosed reserve (Selati Game Reserve). Regarding home ranges, lions had considerable overlap among themselves (especially the females), leopards had minimal overlap, while spotted hyaenas had no home range overlap. Although we found no evidence for spatial partitioning amongst the collared large carnivores, differences in the habitat use patterns of the three large carnivore species is evident. The high prey abundance of Selati, carnivore predation strategies, behavioural adaptations and ecological separation could be facilitating the coexistence of lions, spotted hyaenas and leopards in Selati. We encourage future research to be aimed at investigating the interactions of multiple sympatric carnivores in an attempt to bridge the knowledge gap on which mechanisms structure carnivore communities.

Bradymonabacteria, a novel bacterial predator group with versatile survival strategies in saline environments

BackgroundBacterial predation is an important selective force in microbial community structure and dynamics. However, only a limited number of predatory bacteria have been reported, and their predatory strategies and evolutionary adaptations remain elusive. We recently isolated a novel group of bacterial predators, Bradymonabacteria, representative of the novel order Bradymonadales in δ-Proteobacteria. Compared with those of other bacterial predators (e.g., Myxococcales and Bdellovibrionales), the predatory and living strategies of Bradymonadales are still largely unknown.ResultsBased on individual coculture of Bradymonabacteria with 281 prey bacteria, Bradymonabacteria preyed on diverse bacteria but had a high preference for Bacteroidetes. Genomic analysis of 13 recently sequenced Bradymonabacteria indicated that these bacteria had conspicuous metabolic deficiencies, but they could synthesize many polymers, such as polyphosphate and polyhydroxyalkanoates. Dual transcriptome analysis of cocultures of Bradymonabacteria and prey suggested a potential contact-dependent predation mechanism. Comparative genomic analysis with 24 other bacterial predators indicated that Bradymonabacteria had different predatory and living strategies. Furthermore, we identified Bradymonadales from 1552 publicly available 16S rRNA amplicon sequencing samples, indicating that Bradymonadales was widely distributed and highly abundant in saline environments. Phylogenetic analysis showed that there may be six subgroups in this order; each subgroup occupied a different habitat.ConclusionsBradymonabacteria have unique living strategies that are transitional between the “obligate” and the so-called facultative predators. Thus, we propose a framework to categorize the current bacterial predators into 3 groups: (i) obligate predators (completely prey-dependent), (ii) facultative predators (facultatively prey-dependent), and (iii) opportunistic predators (prey-independent). Our findings provide an ecological and evolutionary framework for Bradymonadales and highlight their potential ecological roles in saline environments.DXyMUwPonspDNwsS-CQ6HaVideo abstract.

Phylogenomic relationships of bioluminescent elateroids define the ‘lampyroid’ clade with clicking Sinopyrophoridae as its earliest member

AbstractBioluminescence has been hypothesized as aposematic signalling, intersexual communication and a predatory strategy, but origins and relationships among bioluminescent beetles have been contentious. We reconstruct the phylogeny of the bioluminescent elateroid beetles (i.e. Elateridae, Lampyridae, Phengodidae and Rhagophthalmidae), analysing genomic data of Sinopyrophorus Bi & Li, and in light of our phylogenetic results, we erect Sinopyrophoridae Bi & Li, stat.n. as a clicking elaterid‐like sister group of the soft‐bodied bioluminescent elateroid beetles, that is, Lampyridae, Phengodidae and Rhagophthalmidae. We suggest a single origin of bioluminescence for these four families, designated as the ‘lampyroid clade’, and examine the origins of bioluminescence in the terminal lineages of click beetles (Elateridae). The soft‐bodied bioluminescent lineages originated from the fully sclerotized elateroids as a derived clade with clicking Sinopyrophorus and Elateridae as their serial sister groups. This relationship indicates that the bioluminescent soft‐bodied elateroids are modified click beetles. We assume that bioluminescence was not present in the most recent common ancestor of Elateridae and the lampyroid clade and it evolved among this group with some delay, at the latest in the mid‐Cretaceous period, presumably in eastern Laurasia. The delimitation and internal structure of the elaterid‐lampyroid clade provides a phylogenetic framework for further studies on the genomic variation underlying the evolution of bioluminescence.

Paired high‐throughput, in situ imaging and high‐throughput sequencing illuminate acantharian abundance and vertical distribution

AbstractAcantharians (supergroup Rhizaria) can be important contributors to surface primary production and to carbon flux to the deep sea, but are often underestimated because their delicate structures are destroyed by plankton nets or dissolved by chemical fixatives. As they are also uncultured, relatively little is known about acantharian biology, especially regarding their life cycles. Here, we take a paired approach, bringing together high‐throughput, in situ imaging and metabarcode sequencing, to investigate acantharian abundance, vertical distribution, and life history in the western North Pacific. Concentrations of imaged acantharian cells correlated well with relative abundances of 18S rRNA gene sequences from acantharians with known, recognizable morphologies, but not to sequences corresponding to acantharians with unknown morphology. These results suggest that morphologically undescribed clades may lack the characteristic star‐shaped acantharian skeleton or are much smaller than described acantharians. The smaller size of acantharians imaged at depth supports current hypotheses regarding nonsymbiotic acantharian life cycles: cysts or vegetative cells release reproductive swarmer cells in deep water and juvenile cells grow as they ascend toward the surface. Moreover, sequencing data present the possibility that some photosymbiotic acantharians may also reproduce at depth, like their nonsymbiotic, encysting relatives, which is counter to previous hypotheses. Finally, in situ imaging captured a new acantharian behavior that may be a previously undescribed predation strategy.

Earwig preying on ambrosia beetle: Evaluating predatory process and prey preference

AbstractEarwigs (Dermaptera), such as Forficula auricularia L., are important euryphagous predators for a wide variety of prey and can markedly influence the populations of orchard pests. Most previous studies on earwig feeding behaviour have not used adult beetles of the prey species; few researchers have focused on prey preference in earwigs. Some fragments of beetle exoskeleton and an earwig adult, Anisolabella marginalis (Dohrn), were found in the same cage, where adults of ambrosia beetle, Euwallacea interjectus (Blandford), were emerging from the logs of a fig tree infected with Ceratocystis canker (fig wilt disease). Thus, A. marginalis was suspected of being a predator of E. interjectus. To shed light on this issue, in the laboratory, we set up a test arena and observed and recorded behavioural interactions between A. marginalis and E. interjectus. E. interjectus was collected from the logs of fig trees and reared on an artificial diet, along with six different ambrosia beetle species, which were collected from a trap (baited with ethanol) and a fallen maple tree. A series of laboratory experiments demonstrated that A. marginalis is actually a predator of E. interjectus and other species of ambrosia beetle, indicating its a potential for use in effective pest control in the field. The predators frequently consume and tend to select their prey depending on prey size, rather than sex and beetle species. Furthermore, earwigs have alternative predatory strategies for dealing with seven different species, although they use their forceps to cut the body of most tested beetles.