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Penelitian ini bertujuan untuk mengetahui pengaruh tumbuhan liar berbunga terhadap keanekaragaman, kemerataan, kekayaan, dan dominansi musuh alami pada ekosistem tanaman tebu. Kegiatan penelitian dilaksanakan pada bulan Desember 2021 – April 2022 di lahan tanaman tebu di Instalasi Penelitian dan Pengkajian Teknologi Pertanian (IP2TP) Balai Penelitian Tanaman Pemanis dan Serat (Balittas), Karangploso, Malang. Penelitian ini menggunakan metode deskriptif kuantitatif dengan perangkap berupa yellow sticky trap dan farmcop. Hasil penelitian dianalisis menggunakan Indeks Keanekaragaman (H’), Indeks Kemerataan (E), Indeks Kekayaan (R), Indeks Dominasi (D), dan menggunakan Uji T dengan taraf kesalahan 5%. Hasil penelitian didapatkan sebanyak 16 jenis musuh alami pada lahan tebu dengan tumbuhan liar berbunga dan 9 jenis musuh alami pada lahan tebu tanpa tumbuhan liar berbunga. Indeks keanekaragaman pada lahan tebu dengan dan tanpa tumbuhan liar berbunga memiliki nilai H’ termasuk kategori sedang, nilai E termasuk kategori hampir merata, nilai R termasuk kategori rendah, dan nilai D kategori rendah. Berdasarkan hasil Uji T terdapat perbedaan rerata populasi musuh alami pada lahan tebu dengan dan tanpa tumbuhan liar berbunga yang berbeda nyata (t hitung > t tabel) yaitu t hitung sebesar 6,343 dan t tabel 2,144.

Abstract Background The Rugose spiraling whitefly (RSW), Aleurodicus rugioperculatus Martin (Hemiptera: Aleyrodidae), has been reported as an invasive pest of coconut in different parts of peninsular India during 2016. It mainly caused damage to coconut palms, bananas, custard apples and other broad-leaved plants as hosts. Presently it is spread all over India and the coconut growing farmers are facing hard ships due to this infestation of RSW in coconut ecosystem. Still now the management of this invasive pest is fully based on the biological control, particularly with predators and parasitoids and the study on the microbial control of RSW was minimum. Hence, an attempt was made to study the ovicidal and insecticidal effects of microbial pathogens, viz. Isaria fumosorosea Wize, Beauveria bassiana (Balsamo) Vuillemi, Metarhizium anisopliae (Metschnikoff), Lecanicillium lecanii (Zimmerm.) with a spore load of 1 × 108 cfu against different life stages of RSW and their chrysopid predator, Mallada boninensis (Okamoto)(Neuroptera: Chrysopidae) under laboratory as well as field conditions. Results The results revealed that under laboratory conditions, I. fumosorosea caused 34.54% egg mortality, 37.39% nymphal mortality and 48.30% adult mortality, followed by L. lecanii (24.54, 30.76 and 28.01%) and M. anisopliae (20.56, 32.51 and 42.92%) for egg, nymphal and adult mortality, respectively. Under field conditions, I. fumosorosea caused (29.60%), followed by M. anisopliae (24.30%) and B. bassiana (21.00%) nymphal mortality, respectively, at 15 days after spray, also, it was found effective in reducing the RSW population on coconut. The impact of fungal entomopathogens against the predator revealed that I. fumosorosea treated eggs of M. boninensis recorded maximum 90.33% grub emergence than other treatments. Conclusion The present study concludes that the RSW can be controlled effectively by I. fumosorosea along with the chrysopid predator, M. boninensis under field conditions as they showed maximum ovicidal and insecticidal actions against different life stages of RSW and safer to the major predator of RSW and fall under harmless category as per the classification of IOBC.

Studies of the effects of landscape composition on pests and their natural enemies on agroforestry systems is still limited, whereas the system can maintain biodiversity. This research investigated the impact of agricultural landscape composition on shaping the interaction between pests and natural enemies in cacao agroforestry. The study was conducted in twelve cacao plantations spread across five districts in East Java, Indonesia. A sampling of insects was carried out by observing the intensity of pest attacks and the diversity and abundance of predators. The surrounding landscape of the cacao field was characterized by manually digitalizing the land use. The results found two main pests attacking all cacao plantations: cacao pod borer, Conophomorpha cramerella (CPB) with attack intensity 0.72-12.05%, and Helopeltis sp. with attack intensity 12.39-42.24%. Management of cacao plantations, such as intensification and canopy cover, significantly affected the attack intensity of CPB but not Helopeltis sp. Based on the generalized linear model, the landscape composition, especially the patch number of natural habitats, positively impacted CPB attack intensity and predator abundance. However, predator abundance harmed CPB attack intensity. In conclusion, the proportion of natural habitat in agricultural landscapes contributes to reducing the attack intensity of pests via maintaining natural enemy abundance.

Deep-sea cephalopods are diverse, abundant, and poorly understood. The Cirrata are gelatinous finned octopods and among the deepest-living cephalopods ever recorded. Their natural feeding behaviour remains undocumented. During deep-sea surveys in the Arctic, we observed Cirroteuthis muelleri. Octopods were encountered with their web spread wide, motionless and drifting in the water column 500–2600 m from the seafloor. Individuals of C. muelleri were also repeatedly observed on the seafloor where they exhibited a repeated, behavioural sequence interpreted as feeding. The sequence (11–21 s) consisted of arm web spreading, enveloping and retreating. Prey capture happened during the enveloping phase and lasted 5–49 s. Numerous traces of feeding activity were also observed on the seafloor. The utilization of the water column for drifting and the deep seafloor for feeding is a novel migration behaviour for cephalopods, but known from gelatinous fishes and holothurians. By benthic feeding, the octopods benefit from the enhanced nutrient availability on the seafloor. Drifting in the water column may be an energetically efficient way of transportation while simultaneously avoiding seafloor-associated predators. In situ observations are indispensable to discover the behaviour of abundant megafauna, and the energetic coupling between the pelagic and benthic deep sea. [ABSTRACT FROM AUTHOR]

In this investigation, we proposed and analyzed a mathematical model among the interaction of prey-predator-scavenger species. Here, the harvesting of predator and scavenger have been considered. It is assumed that prey is consumed by predator and scavenger species consumes both dead prey as well as dead predator. It is also assumed that the scavenger species is partially supported by supplying constant amount of additional food. The boundedness and persistence conditions of the solution of the proposed model are derived. It is found that the model undergoes a Hopf-bifurcation around the interior equilibrium point. It is reported that the harvesting of predator and scavenger species can control the chaotic dynamics and make the system stable in the presence of additional food to the scavenger species. It is also reported that the supplying of additional food may make the system more stable than the system without supplying of additional food. [ABSTRACT FROM AUTHOR]

Knowledge of trophic interaction is necessary to understand the dynamics of ecosystems and develop ecosystem‐based management. The key data to measure these interactions should come from large‐scale diet analyses with good taxonomic resolution. To that end, molecular methods that analyze prey DNA from guts and feces provide high‐resolution dietary taxonomic data. However, molecular diet analysis may also produce unreliable results if the samples are contaminated by external sources of DNA. Employing the freshwater European whitefish (Coregonus lavaretus) as a tracer for sample contamination, we studied the possible route of whitefish in beaked redfish (Sebastes mentella) guts sampled in the Barents Sea. We used whitefish‐specific COI primers for diagnostic analysis, and fish‐specific 12S and metazoa‐specific COI primers for metabarcoding analyses of intestine and stomach contents of fish samples that were either not cleaned, water cleaned, or bleach cleaned after being in contact with whitefish. Both the diagnostic and COI metabarcoding revealed clear positive effects of cleaning samples as whitefish were detected in significantly higher numbers of uncleaned samples compared to water or bleach‐cleaned samples. Stomachs were more susceptible to contamination than intestines and bleach cleaning reduced the frequency of whitefish contamination. Also, the metabarcoding approach detected significantly more reads of whitefish in the stomach than in intestine samples. The diagnostic analysis and COI metabarcoding detected contaminants in a higher and comparable number of gut samples than the 12S‐based approach. Our study underlines thus the importance of surface decontamination of aquatic samples to obtain reliable diet information from molecular data. [ABSTRACT FROM AUTHOR]

Invasive carnivores are threatening the indigenous fauna of Aotearoa, but impacts vary with time, space and species. Conservation strategies require knowledge of predator-prey dynamics specific to different ecosystems and allowing for long-term guild shifts. To build this knowledge, we model the survivorship of the kea, a long-lived, ground-nesting parrot with an expansive species-range, using a dataset spanning two decades (1998–2021) and spanning several forest-dominated South Island montane ecosystems. Kea survivorship was lower in eastern ecosystems compared to western ones, depressed during carnivore irruptions, and elevated after predator control. Kea of all ages and both sexes fell prey to stoats and feral cats whilst foraging and roosting, not whilst nesting. Stoat depredation happened in all ecosystems, whereas feral cats featured more in eastern ones. Annual survivorship was high in most contexts (adults > 90%, juveniles > 70%), but a peak in stoat and feral cat predation in eastern ecosystems during 2020–2021 reduced adult survival to <60%. This predation peak followed a rodent population crash, the primary prey of carnivores in eastern beech forests. We conclude that predator impacts on kea are concentrated into post-mast years. Recommendations for management are provided. [ABSTRACT FROM AUTHOR]

Copyright of Acta Zoologica Lilloana is the property of Fundacion Miguel Lillo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Long-term studies of community composition and relative abundance are key tools in wildlife management and biodiversity conservation. However, few studies of this kind are available for Mediterranean carnivores, especially in the Iberian Peninsula, a hotspot of mammal biodiversity in Europe. We used 15 years of carnivore monitoring data from the Doñana National Park, one of the most representative areas for carnivores in Iberia, to obtain population trends for the main Mediterranean carnivore species. They were positive for red fox, stable for badger and Egyptian mongoose, and negative for common genet and Iberian lynx. The importance of long-term datasets and the implications of the results for the studied species at global level are discussed, above all for species whose population trends are less well known. This is the case of the Egyptian mongoose, for which we present novel information on its long-term population trend in Europe, and of the Iberian lynx, an endangered species with a clear negative trend in this well-protected area. [ABSTRACT FROM AUTHOR]

Bacterial secondary metabolites are a valuable source of various molecules that have antibacterial and anticancer activity. In this study, ten endosymbiotic bacteria of aphids, aphid predators and ants were isolated. Bacterial strains were identified according to the 16S rRNA gene. Ethyl acetate fractions of methanol extract (EA-ME) were prepared from each isolated bacterium and tested for their antibacterial activities using the disk diffusion method. The EA-ME of three bacterial species, Planococcus sp., Klebsiella aerogenes, Enterococcus avium, from the pomegranate aphids Aphis punicae, Chrysoperia carnea, and Tapinoma magnum, respectively, exhibited elevated antibacterial activity against one or several of the five pathogenic bacteria tested. The inhibition zones ranged from 10.00 ± 0.13 to 20.00 ± 1.11 mm, with minimum inhibitory concentration (MIC) values ranging from 0.156 mg/mL to 1.25 mg/mL. The most notable antibacterial activity was found in the EA-ME of K. aerogenes against Klebsiella pneumonia and Escherichia coli, with an MIC value of 0.156 mg/mL. The cytotoxic activity of EA-ME was dependent on the cell line tested. The most significant cytotoxicity effect was observed for extracts of K. aerogenes and E. avium, at 12.5 µg/mL, against the epithelial cells of lung carcinoma (A549), with a cell reduction of 79.4% and 67.2%, respectively. For the EA-ME of K. aerogenes and Pantoea agglomerans at 12.5 µg/mL, 69.4% and 67.8% cell reduction were observed against human colon cancer (Hct116), respectively. Gas chromatography–mass spectrometry (GC-MS) analysis of three EA-ME revealed the presence of several bioactive secondary metabolites that have been reported previously to possess antibacterial and anticancer properties. To the best of our knowledge, this is the first study to examine the biological activities of endosymbiotic bacteria in aphids, aphid predators and ants. The promising data presented in this study may pave the way for alternative drugs to overcome the continued emergence of multidrug-resistant bacteria, and find alternative drugs to conventional cancer therapies. [ABSTRACT FROM AUTHOR]

Context: Microplastic (MP) contamination is a strong candidate to be one of the most important environmental problems worldwide. Microplastics have been detected in many freshwater organisms because of increasing plastic contamination within aquatic ecosystems. However, the correlation between MPs in organisms and their surrounding environments still needs further study. Aim: This is the first study assessing the accumulation of MPs in aquatic fauna from water and sediment by bioaccumulation equations in one of the wastewater basins in Sohag Governorate, Egypt. Methods: Four common freshwater insect families representing different feeding guilds were employed to detect MP contamination. Key results: The collector–gatherers (Chironomidae and Hydrophilidae) recorded the highest MP load per gram wet weight, the highest bioaccumulation factor (BCF), and the biota-sediment accumulation factor (BSAF), whereas predators (Aeshnidae) recorded the lowest values. In both sediment and water, polyester fibres were the most common type of MP, followed by fragments (polyethylene and polypropylene). However, only polyester fibres were found in the different insect taxa. The blue colour was the predominant colour in the water, sediment and insect fauna. The mean length of fibres in the different insects was a little smaller than those in the surrounding environment. Conclusion: The present study suggests that MP ingestion by aquatic insects is not necessarily associated with environmental pollution levels, because other factors such as feeding strategies and habitats may play an important role in MP ingestion. Implications: The presence of MPs in the insects (lower trophic levels) gives a possibility of inter trophic-level transfer through predation. As a result, higher trophic-level studies in different feeding groups should be conducted to detect the potential risk of MPs on different freshwater fauna. Microplastic (MP) contamination is a threat for freshwater systems worldwide. We evaluated MPs in different insect species, sediment and water in a wastewater basin in Sohag, Egypt. The collector–gatherers (Chironomidae) recorded the highest MP load, the highest bioaccumulation factor (BCF), and the biota-sediment accumulation factor (BSAF), whereas predators (Aeshnidae) had the lowest MP lode. Polyester fibres were the dominant polymer in both water and sediment, and the only type in insects. We concluded that feeding guilds of the insect species may play a role in MP load. [ABSTRACT FROM AUTHOR]

Due to human-caused deforestation, global warming, and other environmental factors, habitat fragmentation became widespread. This fragmentation has a variety of detrimental repercussions for many species as well as humans, especially in the agricultural economy. It causes insect outbreaks, the expansion of alien species, and disrupts biological management by rendering the habitat unsuitable for natural enemies in agriculture. Providing natural enemies with additional food is one method to improve the ecosystem and support them. In this study, we assumed that the ecosystem is separated into two patches and that predators can easily migrate from one patch to the next, while prey stays inside its patch's territory. We looked at the impact of offering more food to predators in a patchy environment using dynamical systems theory. The permanence, stability, and various bifurcations that occur in the system are studied using a rigorous mathematical analysis. The study looks at how predator's access to other food sources affects pest management. By adjusting the provided food's characteristic qualities, such as (nutritional) quality and quantity, one can limit and manage the pest in one or both patches, as well as eliminate predators from the ecosystem. This research reveals that providing predators with additional food (of specified quality and quantity) can help in controlling chaotic behavior in the system. The findings of the study are supported by numerical simulations. [ABSTRACT FROM AUTHOR]

This study was carried out to determine the natural enemies and distribution of Tingidae family species in Malkara, Saray, Süleymanpaşa, and Şarköy districts in Tekirdağ. Surveys were conducted on woody plants in 2011-2012. Field surveys were carried out at 10-day intervals between the beginning of April and the end of October. Visual inspection and shaking methods were used for sample collection. As a result of the surveys, as a natural enemy of Tingidae family species belonging Coleoptera order from the Coccinellidae family; Coccinella septempunctata (Linnaeus, 1758), Exochomus quadripustulatus (Linnaeus, 1758), Oenopia conglobata (Linnaeus, 1758), Stethorus gilvifrons (Mulsant, 1850), Hemiptera order from Anthocoridae family; Anthocoris nemoralis (Fabricius, 1794), Orius niger (Wolff, 1811), Orius vicinus (Ribaut, 1923), from Miridae family; Deraeocoris lutescens (Schilling, 1837), Stethoconus pyri (Mella, 1869) and Neuroptera order from Chrysopidae family; Chrysoperla carnea (Stephens, 1836), a total of 10 predatory species were identified. Erythmelus panis (Enock, 1909) from Mymaridae family of Hymenoptera order was determined as egg parasitoid. Stethoconus pyri was the most common species in Tekirdağ province, followed by C. septempuctata while A. nemoralis and S. gilvifrons were the least common species, respectively. The distribution of natural enemies was almost similar to the rate of their presence. It has been determined that all natural enemies in the province feed on Stephanitis pyri (Fabricius, 1775) (Pear lace bug). O. conglobata with Monosteira unicostata (Mulsant & Rey, 1852), except the Pear lace bug; A. nemoralis, O. niger and O. vicinus were also recorded to feed on Corythuca ciliata (Say, 1832). Many of the detected natural enemies are the first record for Tekirdağ fauna. Among these species, according to the observations and the data obtained, S. pyri feeding on Pear lace bug and Orius species feeding on C. ciliata are thought to be more important than other natural enemies. Therefore, in future studies, it would be more appropriate to investigate the biology and activities of these species in laboratory and/or field conditions. [ABSTRACT FROM AUTHOR]

Angoumois Grain Moth, Sitotroga cerealella (Olivier) (Lepidoptera:Gelechiidae) is a serious primary pest of stored grain in many parts of the world. A study was carried out in the laboratory to investigate the effects of grain physical and intrinsic properties, temperature, relative humidity, and grain moisture content on the development and emergence of S. cerealella. The experiment was arranged in completely randomized design with three replicates for each maize genotypes used. Daily temperatures and relative humidity were recorded at 8:00 and 16:00 GMT with a Temperature and Humidity Sensor, which was embedded in the polypropylene bag containing six maize genotypes and tied after each reading to prevent emerging insects from escaping. The number of S. cerealella that emerged was observed weekly. Angoumois grain moth emergence on stored husked maize ears began in the 3rd week through to the 6th week in storage. The moth emergence was higher in the season with higher percentage grain moisture content. A significant (P<0.05) difference was observed in percentage grain moisture within almost all the same genotypes during both major and minor seasons. Aburokokoo, Ahoodzin, and Obatanpa had significantly (P<0.05) higher mean numbers of the emerged moth from the 4th to 6th week. The grain physical and intrinsic characteristics such as surface area and weight of Aburokokoo, Ahoodzin, and Obatanpa were statistically different (P<0.05) from the other three genotypes. A significant positive relationship was observed between grain surface area, grain weight, density and total S. cerealella emerged. Abontem, Honampa, and GH2354 with smaller grain surface area and lower grain weight had smaller mean number of the moth emerging. Anthocoris nemorum (L.) an important generalist agricultural pest predator was observed to be associated with the moth when its population was high (13-63) but none when the moth population was very small (0-4) in store. The association between mean daily temperatures and relative humidity during the 6 weeks storage in both seasons was inversely proportional. About 88.25% of the variation in relative humidity depends on temperature. [ABSTRACT FROM AUTHOR]

A specimen of bull ray Aetomylaeus bovinus was captured dead by a diver around a tuna sea cage farm. It was female, measured 2310 mm in total length (TL) and 1460 mm in disc width (DW) with body weight estimated as about 20 kg. This case was reported from a tuna farm for the first time. The bull ray entered the sea cage about three months ago, but no attack occurred to the tuna in the cage. It was grazing on fouling organisms that attached to the nets. However, the cage nets were replaced with clean ones four days ago before the capture, and the bull ray did not find enough fouling organisms or uneaten fish feed and was starved to death. [ABSTRACT FROM AUTHOR]

There is increasing interest in using natural enemies to control pests in urban green spaces, but this is often hampered by a lack of information on enemies of particular pest groups. Here we provide an assessment for the first time of seasonal population of coccid species and its natural enemies on Chamaecyparis lawsoniana (A. Murray) Parl, 1864. The main coccid pest, Planococcus vovae (Nasonov, 1909), is attacked by parasitoids and predators. According to the gathered data, the peak population of both coccids and their natural enemies was observed in spring. The most common species in natural enemies was, Scymnus syriacus Marseul, 1868. Biodiversity indexes of the natural enemies community in the selected stations demonstrated the highest and lowest amounts for both Shanon winner and Margalef index in S3 and S1 before and after for the Simpson index in S1 and S4,5. This study suggests that the natural enemies of coccids on conifer trees may be more complex and diverse than what was observed in the present study. [ABSTRACT FROM AUTHOR]

Female Sinantherina socialis are freshwater, sessile, colonial rotifers that possess two pairs of distinctive glands (warts) located below the corona. Previous studies demonstrated that colonies are unpalatable to many invertebrate and vertebrate predators; those authors suggested that the warts were a possible source of a chemical deterrent to predation. Here we explore wart ultrastructure and cytochemisty to determine whether the warts function as exocrine glands and if their contents display any allomone-like chemistry, respectively. Externally, the warts appear as elevated bulges without pores. Internally, the warts are specialized regions of the integumental syncytium and therefore acellular. The lipid stain Nile Red labels all four warts. Two lipid membrane probes (sphingomyelin and phosphatidylinositol) also bind the warts and may be staining internal secretion vesicle membranes. In fact, wart ultrastructure is defined by hundreds of membrane-bound secretion vesicles packed tightly together. The vesicles are mostly electron-lucent and crowded into a well-defined cytoplasmic space. The cytoplasm also contains abundant ribosomes, rough endoplasmic reticulum, mitochondria, and Golgi, but nuclei are generally positioned peripheral to the packed vesicles. Absence of muscles around the warts or any signs of direct innervation suggests expulsion of gland contents is forced by general body contraction. A single specimen with 'empty' warts implies that secretions are released en masse from all glands simultaneously. The identity of the chemical secretion remains to be determined, but the lack of osmium and uranyl acetate staining suggests a low abundance or absence of phenols, unsaturated lipids, or NH 2 and –COOH groups. This absence, combined with the positive Nile Red staining, is interpreted as evidence that vesicles contain saturated fatty acids such as lactones that are unpalatable to predators. [ABSTRACT FROM AUTHOR]

The tomato leafminer, Tuta absoluta is a destructive invasive pest of cultivated tomato and other Solanaceae plants, with yield losses of 80-100%. Mirid predators are key natural enemies of T. absoluta, but they also feed on host plants in the absence of their prey. Management of T. absoluta is a challenge due to its high biotic potential, resistance to many insecticides and the absence of sufficiently adapted auxiliary fauna in its new dispersion zones. Olfaction plays an important role in the tritrophic interaction between tomato, its herbivore pest T. absoluta and its mirid predators, which can be influenced by non-host plant odors. However, how non-host odours shape this interaction is poorly understood. Previously, we had demonstrated belowground crop protection properties of certain Asteraceae plants against the root-knot nematode Meloidogyne incognita, pest of tomato and other Solanaceae plants. Additionally, Asteraceae plants impact negatively on feeding behavior of above-ground pests of Solanaceae plants, including the greenhouse whitefly (Trialeurodes vaporariorum) and green peach aphid (Myzus persicae). Here, we tested the hypothesis that foliar volatiles from some of these non-host Asteraceae plants can influence the tomato-T. absoluta-mirid predator tritrophic interaction. In olfactometer assays, T. absoluta females were attracted to volatiles of the Solanaceae host plants tomato and giant nightshade but avoided volatiles of the Asteraceae plants, blackjack and marigold, and the positive control, wild tomato, when tested alone or in combination with the host plants. Coupled gas chromatography-mass spectrometry analysis showed that host and non-host plants varied in their emission of volatiles, mainly monoterpenes and sesquiterpenes. Random forest analysis combined with behavioral assays identified monoterpenes as the host plant attractive blend to T. absoluta and its mirid predator, with sesquiterpenes identified as the non-host plant repellent blend against T. absoluta. Contrastingly, the mirid predator was indifferent to the non-host plant repellent sesquiterpenes. Our findings indicate that terpenes influence the tomato-T. absoluta-mirid predator tritrophic interaction. Further, our results emphasize the importance of studying crop protection from a holistic approach to identify companion crops that serve multi-functional roles. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, a cauda-like structure found in Cunaxidae is defined, and with it the new taxa, Cunaxicaudinae Chen & Jin subfam. nov., and its two new genera, Cunaxicaudus Chen & Jin gen. nov. (type genus) and Brevicaudus Chen & Jin gen. nov., are erected. It is proposed that the specialized cauda may be the result of the evolution of the sperm transfer mode. A cauda-like structure was found, firstly in Cunaxidae, and with it the new taxa Cunaxicaudinae Chen & Jin subfam. nov., and its two new genera, Cunaxicaudus Chen & Jin gen. nov. (type genus) and Brevicaudus Chen & Jin gen. nov., were erected. Cunaxicaudinae Chen & Jin subfam. nov. differs from the known members of the family Cunaxidae by the unique conspicuous cauda derived from the posterior end of the hysterosoma. The generic features of Cunaxicaudus Chen & Jin gen. nov. are as follows: the posterior of the hysterosoma elongated as a much longer cauda; palp between genu and tibiotarsus without apophysis; e1 closer to d1 than f1; and e1 closer to mid-line than c1 and d1. The generic features of Brevicaudus Chen & Jin gen. nov. are as follows: the posterior of hysterosoma elongated as a short cauda; palp between genu and tibiotarsus with one apophysis; distance between setae e1 and d1 approximately equal to e1; and f1, e1 as close to mid-line as c1 and d1 to mid-line. It is proposed that the specialized cauda may be the result of the evolution of the sperm transfer mode. [ABSTRACT FROM AUTHOR]

Copyright of Fire Ecology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gyrodinium jinhaense and G. moestrupii were described within the past two decades, but the interactions between these two Gyrodinium species and copepods remain to be studied. To elucidate these interactions, the ingestion rate of the calanoid copepods Acartia spp. feeding on G. jinhaense, G. dominans, and G. moestrupii was determined. The maximum ingestion rates of A. hongi/A. omorii on G. jinhaense and G. dominans (3680 and 3480 ng C predator−1d−1, respectively) were similar, but they were considerably higher than that on G. moestrupii (1600 ng C predator−1d−1). The largest size and fastest swimming speed of G. moestrupii may be partially responsible for this lowest maximum ingestion rate. The ingestion rates of A. hongi/A. omorii on G. jinhaense, G. dominans, and G. moestrupii at the prey concentrations of both 50 and 100 ng C mL−1 were higher than those on the heterotrophic dinoflagellates Pfiesteria piscicida and Luciella masanensis but lower than those on the heterotrophic dinoflagellates Stoeckeria algicida and Oxyrrhis marina. Therefore, G. jinhaense, G. dominans, and G. moestrupii are moderate heterotrophic dinoflagellate prey for Acartia spp. [ABSTRACT FROM AUTHOR]

Wheat is nowadays the most important source of food on earth. Many pest species have been identified that affect wheat yield and quality negatively. This study was conducted to identify harmful and beneficial insect (predator) species and of the distribution of Sunn pest in wheat cultivation areas in the districts (Siirt province Merkez, Kurtalan, Eruh, Tillo, Şirvan, Pervari, and Baykan) of Siirt Province, Türkiye in 2018 and 2019. Samplings were taken periodically for 1-2 weeks from April to July. The sweep nets, frame, pitfall trap, and visual control methods were used for sampling. At the end of the study, 42 species belonging to 6 orders and 25 families were determined. The distributions of the species were recorded as 27 species belonging to 12 families in Coleoptera, 10 species belonging to 7 families in Hemiptera, 2 species belonging to 2 families in Neuroptera, and 1 species belonging to each family in Hymenoptera, Orthoptera and Diptera. The most common and abundant species: the main pest Eurygaster integriceps Puton, 1881 (Hemiptera: Scutelleridae), the secondary pests Aelia acuminata (Linnaeus, 1758), Dolycoris baccarum (Linnaeus, 1758) (Hemiptera: Pentatomidae), Cephus pygmaeus (Linnaeus, 1767) (Hymenoptera: Cephidae) Gryllus bimaculatus De Geer, 1773, (Orthoptera: Gryllidae) were determined. In the study, a total of 16 species were identified, which is the first record for the local fauna of Siirt province. The highest average density of E. integriceps (2 adult + nymph / m2) was found in the Garzan and Gozpinari locations of the Kurtalan district. Besides, among the beneficial species, general predators Chrysoperla carnea (Stephens, 1836) and Coccinella septempunctata (Linnaeus, 1758) are remark as the most common species [ABSTRACT FROM AUTHOR]

Simple Summary: The present study examined the ability of four Mediterranean aromatic plant species, i.e., oregano, rosemary, sage, and savory, established in hedgerows in orange orchards to support natural enemies of citrus pests in comparison to margins with bare soil or weed vegetation, which is the commonly used management practice. The impact of the aromatic plant hedgerows on conservation of parasitoid wasps, spiders, and predators of insect pests varied with the aromatic plant species and natural enemy group, i.e., savory plants had a positive effect on the abundance of parasitoids and arachnid predators; sage and oregano flowers favored predatory insects, but sage harbored low numbers of parasitoids compared to the main flowering weed species; rosemary hedgerows served as a most suitable habitat for spiders in comparison to the pre-existing weed cover. The results support the use of the tested aromatic plant species as customized reservoirs for certain groups of beneficial arthropods in orange orchards, considering also the possible incorporation of suitable flowering wild plant species in the weed flora. In the present study, the potential of hedgerows from Mediterranean aromatic plant species, i.e., oregano, rosemary, sage, and savory, in orange field margins to function as reservoirs of natural enemies of citrus pests was tested in comparison to the common management practice of bare soil or weed vegetation. Assessments were based on the abundance and diversity of parasitoid wasps, spiders, and insect predators in the field margins and on the orange trees for two growing seasons. Savory plants harbored more parasitoids compared to weed vegetation and the other aromatic plants (savory > organic rosemary > sage > oregano). Weed vegetation hosted more arachnid predators than the aromatic plants in their first year in the orchard, but this was reversed with their full growth in the following year (most abundant on rosemary). Oregano and sage favor insect predators. The similarity of the natural enemy communities on the field margins and on the orange trees increased with time, indicating the insects' movement from the field margins to the trees. The results support the use of the tested aromatic plant species in conservation practices for targeted groups of beneficial arthropods in orange orchards, also considering the exploitation of suitable wild flowering plants of the weed flora. [ABSTRACT FROM AUTHOR]

Large carnivores are recovering in many landscapes where the human footprint is simultaneously growing. When carnivores encounter humans, the way they behave often changes, which may subsequently influence how they affect their prey. However, little research investigates the behavioural mechanisms underpinning carnivore response to humans. As a result, it is not clear how predator–prey interactions and their associated ecosystem processes will play out in the human‐dominated areas into which carnivore populations are increasingly expanding.We hypothesized that humans would reduce predation risk for prey by disturbing carnivores or threatening their survival. Alternatively, or additionally, we hypothesized that humans would increase predation risk by providing forage resources that congregate herbivorous prey in predictable places and times.Using grey wolves Canis lupus in Jackson Hole, Wyoming, USA as a study species, we investigated 170 kill sites across a spectrum of human influences ranging from heavily restricted human activities on protected federal lands to largely unregulated activities on private lands. Then, we used conditional logistic regression to quantify how the probability of predation changed across varied types and amounts of human influences, while controlling for environmental characteristics and prey availability.Wolves primarily made kills in environmental terrain traps and where prey availability was high, but predation risk was significantly better explained with the inclusion of human influences than by environmental characteristics alone. Different human influences had different, and even converse, effects on the risk of wolf predation. For example, where prey were readily available, wolves preferentially killed animals far from motorized roads but close to unpaved trails. However, wolves responded less strongly to humans, if at all, where prey were scarce, suggesting they prioritized acquiring prey over avoiding human interactions.Overall, our work reveals that the effects of large carnivores on prey populations can vary considerably among different types of human influences, yet carnivores may not appreciably alter predatory behaviour in response to humans if prey are difficult to obtain. These results shed new light on the drivers of large carnivore behaviour in anthropogenic areas while improving understanding of predator–prey dynamics in and around the wildland–urban interface. [ABSTRACT FROM AUTHOR]

Accurate estimates of distribution and population density are critical for the management of threatened species. This is particularly pertinent for mammalian predators, whose generally low population density, elusive nature, and large home range requirements make it difficult to detect declines. We aimed to refine population estimates of the northern spotted‐tailed quoll (Dasyurus maculatus gracilis) in the Wet Tropics bioregion, to estimate the total number of adults, the likely size of subpopulations across the known distribution of the subspecies, and its associated conservation status. We performed targeted upland camera‐trapping surveys from June 2017 to May 2019. To calculate population densities, we used a combination of the number of individuals identified from each survey and the mean maximum distance moved from three life history stages. We then extrapolated these estimates to modelled suitable habitat areas, refined by the camera‐trapping surveys. Population sizes for the six defined subpopulations were estimated, and ranged from approximately 5 to 105 individuals. The total population was estimated to be 221 individuals. This total population estimate, and the estimates for each of the subpopulations, are lower than previous published estimates and are cause for concern. Given the low population estimates presented here and unresolved threats driving declines in some subpopulations, we suggest elevation of this subspecies to Critically Endangered under the EPBC Act. [ABSTRACT FROM AUTHOR]

Understanding the fish's food and feeding habits is essential in aquaculture and research on invasive species. Butis koilomatodon is one of the potential candidates for aquaculture in the Mekong Delta because it can survive in a wide range of water temperature (26-36 °C) and salinity (3.8-37.25%), but data on this fish species' food and feeding habit are still fragmented and deficient. Consequently, this research aims at supplying necessary data related to diet compositions and feeding activity of Butis koilomatodon collected in six estuarine areas of Mekong delta from April 2019 to March 2020. A total number of 1,227 specimens of Butis koilomatodon (891 males and 336 females) were analyzed diet composition and feeding strategy based on the kinds of food they consumed. The results show that four main food categories were shrimps, small fish, Polychaeta, and detritus, of which the highest frequency of prey is shrimp while the lowest one is Polychaeta. The gender and fish size do not affect this species' dietary constituent; however, the changes in seasons and sampling sites impact on the diet composition of these species. The shrimps, small fish, and detritus contribute to regulating the food composition of Butis koilomatodon between two seasons and among the six sampling sites. In combination with the modified Costello graphic, all fish specimens' gut fullness suggested that Butis koilomatodon is a predator with high feeding intensity. The findings can supply the fundamental knowledge about the nutrient biology of Butis koilomatodon and be useful for artificial cultivating this fish. [ABSTRACT FROM AUTHOR]

Research on predatory predation of Paederus sp. (Coleoptera: Staphylinidae) was carried out to study the functional response of the predator Paederus sp. Functional response is a form and size predictor of consumer impact on resource populations, determining the effectiveness of a predator as an agent in biological control. Predation time in hungry and nothungry conditions influences predator-prey interactions, which are essential in functional response. The method used in predating Paederus sp. on the prey of aphids was Aphid spp. They are using four levels of prey density with two different predator treatments. The results show the functional response model of Paederus sp. predators. against the prey of Aphid spp. Described in a type II model. The level of predation of Paederus sp. showed different results for the two treatments and an increasing cystoid curve at a rising rate. The level of predation is still increasing, along with the increase in host density, and can be a starting point for controlling the Aphid spp and using predators Paederus sp. in the field. [ABSTRACT FROM AUTHOR]

Background: Citizen science is a research approach that involves collaboration between professional scientists and non-professional volunteers. The utilisation of recent online citizen-science platforms (e.g. social networking services) has greatly revolutionised the accessibility of biodiversity data by providing opportunities for connecting professional and citizen scientists worldwide. Meteorus stellatus Fujie, Shimizu & Maeto, 2021 (Hymenoptera, Braconidae, Euphorinae) has been recorded from the Oriental Islands of Japan and known to be a gregarious endoparasitoid of two macro-sized sphingid moths of Macroglossum, Ma. passalus (Drury) and Ma. pyrrhosticta Butler. It constructs characteristic star-shaped communal cocoons, suspended by a long cable. Although M. stellatus has been reported only from the Oriental Islands of Japan, the authors recognise its occurrence and ecological data from Taiwan and the Palaearctic Island of Japan through posts on online citizen-science groups about Taiwanese Insects on Facebook and an article on a Japanese citizen-scientist's website. New information: Through collaboration between professional and citizen scientists via social media (Facebook groups) and websites, the following new biodiversity and ecological data associated with M. stellatus are provided: 1. Meteorus stellatus is recorded for the first time from Taiwan and the Palaearctic Region (Yakushima Is., Japan). 2. Cechetra minor (Butler, 1875), Hippotion celerio (Linnaeus, 1758) and Macroglossum sitiene (Walker, 1856) (Lepidoptera, Sphingidae) are recorded for the first time as hosts of M. stellatus and two of which (C. minor and H. celerio) represent the first genus-level host records for M. stellatus. 3. Mesochorus sp. (Hymenoptera, Ichneumonidae), indeterminate species of Pteromalidae and Trichogrammatidae (Hymenoptera), are recognised as hyperparasitoid wasps of M. stellatus. 4. Parapolybia varia (Fabricius, 1787) (Hymenoptera, Vespidae) is reported as a predator of pendulous communal cocoons of M. stellatus. The nature of suspended large-sized communal cocoons of M. stellatus and the importance and limitations of digital occurrence data and online citizen science are briefly discussed. [ABSTRACT FROM AUTHOR]

Context: African lion (Panthera leo) populations are declining throughout Africa, but the problem is particularly acute in southern Kenya, where human–lion conflict is common. Aims: Using the Kuku Group Ranch (KGR) in southern Kenya as a case study, we investigated lion diet and the potential drivers of temporal variation in cattle depredation. Methods: Using GPS clusters, we investigated the main prey species consumed by lions to determine lion diet. Prey preference of lions in relation to prey availability was then assessed using a Jacobs index to determine whether cattle or wild prey were preferred. We used reported depredation events recorded by verification officers over 36 months (2016–2018) to investigate whether temporal variation in cattle depredation by lions was linked to variation in lag rainfall, normalised difference vegetation index (NDVI) or availability of the most important large non-domestic prey items. Key results: Six prey species (cattle, Bos taurus ; Burchell's zebra, Equus quagga ; Coke's hartebeest, Alcelaphus cokeii ; Maasai giraffe, Giraffa tippelskirchi ; blue wildebeest, Connochaetes taurinus ; and eland, Tragelaphus oryx) made up 92% of the biomass consumed by lions on KGR. Cattle are the most consumed prey item and contribute the second most to consumed biomass after giraffe. However, once prey availability is considered, lions preferred wild prey. Verification officers identified 330 cattle depredation events over 3 years, and we show that the most important predictor of monthly cattle depredation by lions was cumulative rainfall in the preceding 3 months. Conclusions: Our results on cattle depredation by lions showed that rainfall and its influence on the environment are important drivers of cattle depredation. Understanding the mechanistic link between lion depredation and rainfall enables us to predict when depredation events may increase and allows hypotheses on the reason why this spike in depredation takes place to be explored. Implications: Given that climate-change models indicate that East Africa will experience prolonged and increased seasonal rainfall, we predict that periods when cattle are vulnerable to lion depredation may increase. Therefore, it is imperative to ensure that cattle husbandry is improved during these wetter periods to minimise the risk of conflict and retaliatory killing of lions. Retaliatory killing of lions is a threat to African lion (Panthera leo) populations. Our study took place in the Tsavo–Amboseli ecosystem, Kenya, assessing lion diet and cattle depredation. The most common species consumed by lions were cattle, whereas lag rainfall was an important predictor of cattle depredation. The findings provide opportunities to develop proactive husbandry interventions to reduce cattle depredations. Photograph by Iain Olivier. [ABSTRACT FROM AUTHOR]

Abstract Human‐driven land use change can fundamentally alter ecological communities, especially the diversity and abundance of large‐bodied predators. Yet, despite the important roles large‐bodied predators play in structuring communities through feeding, there have been only a few investigations of how the feeding patterns of large‐bodied predators change in human‐dominated landscapes. One group of large‐bodied predators that has been largely overlooked in the context of land use change is the crocodilians. To help fill these gaps, we studied the feeding patterns of juvenile American alligators (Alligator mississippiensis) on neighboring barrier islands on the southeast coast of Georgia, USA. Jekyll Island has multiple golf courses and substantial amounts of human activity, while Sapelo Island does not have any golf courses and a much smaller amount of human activity. We found that juvenile alligator populations on both islands ate the same types of prey but in vastly different quantities. Sapelo Island alligators primarily consumed crustaceans while alligators that lived on Jekyll Island's golf courses ate mostly insects/arachnids. Furthermore, the Jekyll Island alligators exhibited a much more generalist feeding pattern (individuals mostly ate the same types of prey in the same quantities) than the more specialized Sapelo Island alligators (diets were more varied across individuals). The most likely explanation for our results is that alligators living on golf courses have different habitat use patterns and have access to different prey communities relative to alligators in more natural habitats. Thus, land use change can strongly alter the feeding patterns of large‐bodied predators and, as a result, may affect their body condition, exposure to human‐made chemicals, and role within ecological communities.

A three-species model of the interactions of crop, pest, and predator has been constructed in this work. In the absence of pests and harvesting of crops, the rate of crop growth is considered as logistic. It is considered that pests consume crops whereas predators consume pests. Harvesting of the crops has been considered here. Holling type II functional response has been considered for crop and pest consumption. It is also assumed that the predators may consume pests via Holling type II functional response. Positivity and boundedness of the solution of the model have been investigated. The various equilibrium points of the model are evaluated, and the local and global stability are then investigated. Studies on the Hopf bifurcation existence criterion in connection to a crucial model parameter have been conducted. The optimal crop harvesting has then been determined using an objective function that has been defined. The Pontryagin’s maximum theory is used to calculate the ideal crop harvesting rate. The consumption of pests by predators has been proven to help keep the system stable up to a point, but a higher rate of pest consumption by predators can potentially cause instability. According to observation, the model may become unstable as the mortality rate of predators of pests rises. It is found that the increase in optimal harvesting of crops may lead the model towards stability. It has been noted that increased rate of crops consumption by pests may result in lower agricultural yields.

Abstract Increased predation where ground cover is reduced after severe wildfire is increasingly implicated as a factor causing decline of vulnerable prey populations. In arid central Australia, one species detrimentally affected by repeated wildfire is the great desert skink or tjakura (Liopholis kintorei), a distinctive lizard of the central Australian arid zone that constructs and inhabits multi‐entranced communal burrows. We aimed to test whether tjakura or predator activity at burrow entrances varied with cover and how tjakura respond to predator presence. Using time‐lapse photography, we monitored tjakura and predator activity at the largest entrance of 12 burrows ranging from high (>70%) to low (

ABSTRACT Halobacteriovorax is a genus of naturally occurring marine predatory bacteria that attack, replicate within, and lyse vibrios and other bacteria. This study evaluated the specificity of four Halobacteriovorax strains against important sequence types (STs) of clinically relevant Vibrio parahaemolyticus, including pandemic strains ST3 and ST36. The Halobacteriovorax bacteria were previously isolated from seawater from the Mid-Atlantic, Gulf of Mexico, and Hawaiian coasts of the United States. Specificity screening was performed using a double agar plaque assay technique on 23 well-characterized and genomically sequenced V. parahaemolyticus strains isolated from infected individuals from widely varying geographic locations within the United States. With few exceptions, results showed that Halobacteriovorax bacteria were excellent predators of the V. parahaemolyticus strains regardless of the origins of the predator or prey. Sequence types and serotypes of V. parahaemolyticus did not influence host specificity, nor did the presence or absence of genes for the thermostable direct hemolysin (TDH) or the TDH-related hemolysin, although faint (cloudy) plaques were present when one or both hemolysins were absent in three of the Vibrio strains. Plaque sizes varied depending on both the Halobacteriovorax and Vibrio strains evaluated, suggesting differences in Halobacteriovorax replication and/or growth rates. The very broad infectivity of Halobacteriovorax toward pathogenic strains of V. parahaemolyticus makes Halobacteriovorax a strong candidate for use in commercial processing applications to enhance the safety of seafoods. IMPORTANCE Vibrio parahaemolyticus is a formidable obstacle to seafood safety. Strains pathogenic to humans are numerous and difficult to control, especially within molluscan shellfish. The pandemic spread of ST3 and ST36 has caused considerable concern, but many other STs are also problematic. The present study demonstrates broad predatory activity of Halobacteriovorax strains obtained along U.S. coastal waters from the Mid-Atlantic, Gulf Coast, and Hawaii toward strains of pathogenic V. parahaemolyticus. This broad activity against clinically relevant V. parahaemolyticus strains suggests a role for Halobacteriovorax in mediating pathogenic V. parahaemolyticus levels in seafoods and their environment as well as the potential application of these predators in the development of new disinfection technologies to reduce pathogenic vibrios in molluscan shellfish and other seafoods.

The occurrence and status of natural enemies of honey bee Apis mellifera (Hymenoptera: Apidae) in the southwestern region of Saudi Arabia was conducted during 2019 and 2020. The existence of natural enemies, particularly pests and predators, is one of the most significant problem for beekeepers in the Asir region. A total of 78 apiaries were selected from two different geographical locations (Sarat and Tihama) in the Asir region. Honey bee colonies were attacked by 17 pests and predators species in the Tihama region, compared to 15 in Sarwat mountain region of southwestern Saudi Arabia. In order of significance, wasp (Philanthus triangulum), bee-eating bird (Merops apiaster), Varroa-mite (Varroa destructor), wax moth (Achroia grisella), and spider (Misumena sp.) are the most prevalent pests that inflict major harm to apiaries in southwestern Saudi Arabia. There were also some other pests and predators that had insignificant effect on bees. Generally, the recorded natural enemy’s incidences usually occurred in the months of September-October and December to February.

Abstract Fear of predation can affect important ecosystem processes by altering the prey traits expression that, in turn, regulates the quantity and quality of nutritional inputs to soil. Here, we aimed to assist in bridging a knowledge gap in this cascading chain of events by exploring how risk of spider predation may affect grasshopper prey performances, and the activity of various microbial extracellular enzymes in the soil. Using a mesocosms field‐experiment, we found that grasshoppers threatened by spider predation ate less, grew slower, and had a higher body carbon to nitrogen ratio. Herbivory increased activity of all microbial extracellular enzymes examined, likely due to higher availability of root exudates. Predation risk had no effect on C‐acquiring enzymes but decreased activity of P‐acquiring enzymes. We found contrasting results regarding the effect of predation on the activity of N‐acetyl‐glucosaminidase and leucine arylamidase N‐acquiring enzymes, suggesting that predation risk may alter the composition of N‐inputs to soil. Our work highlighted the importance of soil microbial enzymatic activity as a way to predict how changes in the aboveground food‐web dynamics may alter key ecosystem processes like nutritional‐cycling.

Abstract Perceived predation risks by terrestrial predators are major ecological forces in aquatic systems, particularly for aggregating fish. Riverscape thermal refuges are discrete, localized cold‐water patches where fish temporarily aggregate to buffer against heat events. Predation pressures by terrestrial predators at thermal refuges may decrease the thermoregulatory benefits of refuge use, but quantifying such effects can be challenging and controversial when sampling can impose additional stress on fish. We passively monitored terrestrial predator visitation patterns and predation at four thermal refuges in the Housatonic River, Connecticut, USA, between May 18th and September 29th, 2022, with camera traps, a common wildlife monitoring method. Specifically, we (1) assessed diel visitation patterns by different categories of terrestrial predators at thermal refuges and determined if patterns varied among predator categories or with prevailing environmental conditions, and (2) estimated the probability of predation by hour of the day combined across all predator categories, quantifying general predation pressures at refuges. We detected at least one terrestrial predator at a thermal refuge each day, and mean hourly visitation rates (count/h) were highly variable across predator categories and sampling dates. The most supported generalized additive mixed model indicated that terrestrial predator visitation rates (count/h/day) varied with mean daily river discharge and water temperature differential, and relationships differed across categories of terrestrial predators. We observed 22 separate predation attempts on thermoregulating salmonids and predicted that the probability of predation by any terrestrial predator increased from 0.002 to 0.017 throughout a 24 h day (p = .004). Camera traps provided novel evidence that terrestrial predators are pervasive at riverine thermal refuges, which is relevant for refuge conservation and management globally. We recommend the implementation of a coordinated monitoring network across riverine thermal refuges using camera traps, further enriching our ecological understanding of cumulative predator effects in refuges across complex riverscapes.

With about 8000 marine benthic species, the amphipod crustaceans form one of the richest animal groups of the worldwide Ocean. They have colonized a wide range of soft- and hard-bottom natural and artificial habitats extending from the intertidal to hadal zones. Moreover, they show a broad size spectrum, with numerous giant species exceeding 20 cm in length and some species smaller than 2 mm. When biofouling artificial hard surfaces, some tube-building species can form very dense populations comprising up to 100,000 individuals per square meter. Amphipods are important prey for fish and mammals. Along with cephalopod juveniles, they are also included in the trophic diet of shorebirds that consume amphipods mostly during the low tide on tidal flats. They display diel migration, which reinforces the predation by demersal fish in the suprabenthic zone just above the sea bed, as well as by pelagic fish in the water column. Despite their importance in terms of biodiversity and trophic transfer, no general overview is available on the role of benthic amphipods in marine ecosystem food webs. Various methods, including laboratory and field experiments, as well as the analysis of stomach contents and DNA extraction, have been used to identify the prey/predator trophic links. Based on an extensive literature review, this study discusses the role of marine benthic amphipods as potential food for higher trophic levels in natural and artificial hard-bottom communities created via the construction of offshore wind farms.

The effects of water temperature on individual and group movement behaviour in prey fish can affect ecological interactions such as competition and predation, but how variability in temperature influence fish behaviour is less understood. Of particular concern is how increased warming in tidally fluctuating estuaries may impact the native and endangered delta smelt (Hypomesus transpacificus, Osmeridae). To help address this issue, we tested the effects of increased water temperature (fluctuating [17–21°C] and warm [21°C] acclimated treatments) on juvenile delta smelt individual and group behaviour, response to chemical alarm and predator cues, as well as capacity to evade predation. In addition, predation of delta smelt was tested in the presence of a dominant invasive competitor, Mississippi silversides (Menidia beryllina, Atherinopsidae), as well as comparative predation mortality on Mississippi silversides when isolated. After 7 days of increased temperature treatments, delta smelt in the warm treatment increased swimming velocity, decreased turning angle, and altered group structure with larger inter-individual distances compared to fish in the control (17°C) and fluctuating temperature treatments. Following conspecific and predator chemical alarm cues, delta smelt showed anti-predator responses. Control and fluctuating treatment fish responded to conspecific cues with increased swimming speeds, decreased inter-individual distances and near-neighbour distances, and, after 15 min, fish recovered back to baseline behaviours. In contrast, fish in the warm treatment had not recovered after 15 min, and swimming speeds were maintained at roughly 25 cm/s, close to maximum capabilities. Fish in control and fluctuating treatments showed minimal responses to predator cues, whereas delta smelt exposed to warm conditions significantly increased swimming speeds and decreased turning angle. Predation of delta smelt by largemouth bass (Micropterus salmoides, Centrarchidae) was greatest under the warm treatment, correlating with altered behaviours of delta smelt; however, predation of Mississippi silversides was greater than delta smelt, independent of temperature. This study provides novel insight into the group behaviour of delta smelt, their response to predation, and how prolonged exposure to elevated temperature may induce negative individual and group behaviours causing alterations in predator–prey dynamics. This work highlights the importance of testing ecologically realistic temperature fluctuations in experiments as delta smelt had significantly altered responses to elevated temperature, dependent on variability of warming.

Omnivory has been cited as an explanation for why trophic cascades are weak in many ecosystems, but empirical support for this prediction is equivocal. Compared to predators that feed only on herbivores, top omnivores-species that feed on both herbivores and primary producers-have been observed generating cascades ranging from strong to moderate, null, and negative. To gain intuition about the sensitivity of cascades to omnivory, we analyzed models describing systems with top omnivores that display either fixed or flexible diets, two foraging strategies that are supported by empirical observations. We identified regions of parameter space, wherein omnivores following a fixed foraging strategy, with herbivores and producers comprising a constant proportion of the diet, non-intuitively generate stronger cascades than predators that are otherwise demographically identical: (1) high productivity relative to herbivore mortality and (2) small discrepancies in producer vs. herbivore reward create conditions in which cascades are stronger with moderate omnivory. In contrast, flexible omnivores that attempt to optimize per capita growth rates during search never induce cascades that are stronger than the case of predators. Although we focus on simple models, the consistency of these general patterns together with prior empirical evidence suggests that omnivores should not be uniformly ruled out as agents of strong trophic cascades.

The Sacramento–San Joaquin Delta has been invaded by several species of non-native predatory fish that are presumed to be impeding native fish population recovery efforts. Since eradication of predators is unlikely, there is substantial interest in removing or altering manmade structures in the Delta that may exacerbate predation on native fish (contact points). It is presumed that these physical structures influence predator-prey dynamics, but how habitat features influence species interactions is poorly understood, and physical structures in the Delta that could be remediated to benefit native fish have not been inventoried completely. To inform future research efforts, we reviewed literature that focused on determining the effects of predator-prey interactions between fish, based on contact points that are commonly found in the Delta. We also performed a geospatial analysis to determine the extent of potential contact points in the Delta. We found that the effects of submerged aquatic vegetation (SAV) and artificial illumination are well studied and documented to influence predation in other freshwater systems worldwide. Conversely, other common structures in the Delta—such as docks, pilings, woody debris, revetment, and water diversions—did not have the same breadth of research. In the Delta, the spatial extent of the different types of contact points differed considerably. For example, 22% of the Delta water surface area is occupied by SAV, whereas docks only cover 0.44%. Our conclusion, based on both the literature review and spatial analysis, is that the effects of SAV and artificial illumination on predation warrant the most immediate future investigation in the Delta.

Mononchida members are predatory nematodes with the potential to reduce the number of plant-parasitic nematodes in the soil. During a survey on Mononchida in Iran, several populations of Mylonchulus were recovered from various localities. A population of M. hawaiiensis was studied using 18S rDNA. The phylogenetic analysis using Bayesian inference placed the sequenced M. hawiinesis (OP210758) together with other M. hawaiiensis from Japan (AB361438-AB361442) with a 1.00 posterior probability support. In addition, morphological differences between six Mylonchulus (Nematoda; order: Mononchida; Family: Mylonchulidae) populations were investigated in Iran using discriminant analyses (DA), PERMANOVA, and principal coordinate analysis (PCoA). The purpose was to evaluate the efficacy of PCoA and DA in separating the Mylonchulus species, namely M. sigmaturus, M. paitensis, M. lacustris, M. brachyuris, M. kermaninesis, and M. hawaiiensis. To achieve this, 16 morphometric measurements (body length, a, b, c, c′, V, G1, G2, buccal cavity length, buccal cavity width, dorsal tooth apex, dorsal tooth length, neck length, amphid from anterior end, rectum, and tail length) were made on 160 specimens. The analysis of variance showed that all features were significantly different among the species, except a, b, and the amphid position from the anterior end and tail length. The stepwise discriminant analysis revealed that body length, tail length, neck length, and c′ value were the four most discriminating variables useful to distinguish clearly the six species of Mylonchulus. The variables with strong discriminatory power correctly classified 98.87% of individuals from Iran’s sample of known Mylonchulus species. The results provide a morphometric basis for effectively distinguishing Mylonchulus species.

Abstract Background The invasive barnacle scale, Ceroplastes cirripediformis Comstock (Hemiptera: Coccidae), is a pest native to South America and the Caribbean islands that has recently emerged as a serious threat to agricultural, horticultural, ornamental, medicinal, and aromatic plants. Finding indigenous natural enemies to control the invasive pests is the first step for developing a biological control program. Results The present study reports Eublemma scitula (Rambur) (Lepidoptera: Erebidae) for the first time as a predator of C. cirripediformis in India. The identity of E. scitula was confirmed morphologically based on male genitalia and mitochondrial cytochrome oxidase I (mt COI) gene sequences. E. scitula larvae were found as dominant predators of C. cirripediformis. The predatory activity of E. scitula was observed from June to September, with its peak population recorded during mid-July (2.1 larvae per 25 cm of infested shoot). Conclusion This is the first global record of E. scitula predating on an invasive barnacle scale insects from India. Furthermore, studies on the feeding potential of E. scitula under controlled and field conditions need to be evaluated for utilizing them as a biocontrol agent against C. cirripediformis.

Abstract Aim The largemouth bass Micropterus salmoides was introduced in more than 50 countries for the purpose of sport fishing. In Brazil, records date from 1922, and nowadays many populations are known to occur in the southern region. Here we investigated the reproductive biology of this species in a small reservoir in southern Brazil, to understand the role of the reproductive strategy in the invasion process and assist in its management. We conclude with suggestions for the management in local scale, as this species can bring relevant problems to the public supply through trophic cascade and other negative effects. Methods Samples were performed with different methods, between May 2011 and April 2012. All fishes were measured, and the reproductive season was determined through the relative frequency of reproductive stages and the gonadosomatic index. Sex ratio was calculated monthly and for each total length (TL) class and compared with the estimates presented in the literature. Total length at maturity (L50, length at which 50% of the individuals were mature) was estimated for females, males and the entire study population. Results A total of 565 individuals of M. salmoides were analyzed. Overall sex-ratio did not differ significantly. The monthly distribution of the gonadosomatic index for females and males showed higher values between August (late winter) and November 2011 (austral spring). ��-Binomial modelling of sex-ratio data of native (n=1) and introduced populations (n=7) showed a lower proportion of females in its native range. All individuals > 21.5 cm TL were mature (L95), and L50 was calculated at 18.7 cm TL. After the reproductive period, an increase in the abundance of young individuals (≤ 7.0 cm TL) was registered, corresponding to 50% of all individuals collected. The relative frequency of mature individuals and the variation in the gonadosomatic index indicate a prolonged spawning period during the austral spring, coinciding with the increase in temperature. Conclusions Results suggested that some changes in life history traits, such as the early sexual maturation and the long reproductive period, coupled with a remarkable adaptability, may have facilitated the establishment of M. salmoides populations in this reservoir. The illegal and intentional stocking by anglers plays a central role in the introduction and dispersal of M. salmoides in Brazil. We encourage studies on the sanitary quality of this fish for human consumption, so that massive campaigns of education the population to encourage capture and consumption are implemented by the competent authorities as a control measure in local scale, combined with targeted samplings with artificial baits during the reproductive period, identification, and removal of nests and fingerlings using electric fishing or trap nets during the recruitment period.

In aquatic environments, many prey animals, including anuran larvae, predominantly use chemical cues to assess predation risk. In such systems, a variety of chemical cues (e.g., kairomones, alarm, dietary) affect the behavioral responses of the prey tadpoles. Many anuran tadpoles are able to discriminate different chemical cues and exhibit differential antipredator behavioral responses according to the perceived risk. The behavioral responses of tadpoles of Clinotarsus curtipes to predatory larvae of the dragonfly Pantala flavescens were studied in the laboratory. The predator’s kairomones (water conditioned by a starved predator) or its diet-derived metabolites released in excreta of a predator after consumption of conspecific (C. curtipes) or heterogeneric (Indosylvirana temporalis) prey tadpoles were used to simulate predation threat. The tadpoles of C. curtipes had no behavioral response to predator kairomones. However, the tadpoles showed antipredator behavioral responses i.e., reduced swimming movements and overall time spent swimming, and had a higher burst speed in response to water-borne cues released from the excreta of predators fed both conspecific and heterogeneric prey. The antipredator behavioral responses of tadpoles were most intense in response to cues of predators fed on conspecific prey. The findings of the present study show that tadpoles of C. curtipes are capable of assessing levels of predation threat and modulating the intensity of their defense behavior in accordance with the perceived threat.

ABSTRACT Most bacteria, including model organisms such as Escherichia coli, Bacillus subtilis, and Caulobacter crescentus, reproduce by binary fission. However, some bacteria belonging to various lineages, including antibiotic-producing Streptomyces and predatory Bdellovibrio, proliferate by nonbinary fission, wherein three or more chromosome copies are synthesized and the resulting multinucleoid filamentous cell subdivides into progeny cells. Here, we demonstrate for the first time that the predatory bacterium Bdellovibrio bacteriovorus reproduces through both binary and nonbinary fission inside different prey bacteria. Switching between the two modes correlates with the prey size. In relatively small prey cells, B. bacteriovorus undergoes binary fission; the FtsZ ring assembles in the midcell, and the mother cell splits into two daughter cells. In larger prey cells, B. bacteriovorus switches to nonbinary fission and creates multiple asynchronously assembled FtsZ rings to produce three or more daughter cells. Completion of bacterial cell cycle critically depends on precise spatiotemporal coordination of chromosome replication with other cell cycle events, including cell division. We show that B. bacteriovorus always initiates chromosome replication at the invasive pole of the cell, but the spatiotemporal choreography of subsequent steps depends on the fission mode and/or the number of progeny cells. In nonbinary dividing filaments producing five or more progeny cells, the last round(s) of replication may also be initiated at the noninvasive pole. Altogether, we find that B. bacteriovorus reproduces through bimodal fission and that extracellular factors, such as the prey size, can shape replication choreography, providing new insights about bacterial life cycles. IMPORTANCE Most eukaryotic and bacterial cells divide by binary fission, where one mother cell produces two progeny cells, or, rarely, by nonbinary fission. All bacteria studied to date use only one of these two reproduction modes. We demonstrate for the first time that a predatory bacterium, Bdellovibrio bacteriovorus, exhibits bimodal fission and the mode of division depends on the size of the prey bacterium inside which B. bacteriovorus grows. This work provides key insights into the mode and dynamics of B. bacteriovorus proliferation in different pathogens that pose a major threat to human health due to their emerging antibiotic resistance (Proteus mirabilis, Salmonella enterica, and Shigella flexneri). The use of predatory bacteria such as B. bacteriovorus is currently regarded as a promising strategy to kill antibiotic-resistant pathogens. We find that B. bacteriovorus employs different chromosome replication choreographies and division modes when preying on those pathogens. Our findings may facilitate the design of efficient pathogen elimination strategies.

Humans can markedly alter the temporal activity of wildlife. The ecological consequences of such temporal shifts are poorly understood but can lead to reduced fitness, increased competition, and trophic cascades under certain conditions. Furthermore, if individuals or species vary in their tolerance of human disturbance, then more resiliant individuals/species may be able to exploit resources eschewed by their more human-tolerant counterparts. Here, we explored the potential of a “temporal-shield” offered by human disturbance, using brown bears (Ursus arctos) foraging on sockeye salmon (O. nerka) in southwestern Alaska as a model system. We deployed motion-activated cameras on six salmon spawning streams over five summers (2013–2018), capturing footage of 1935 independent bear encounters including single adult bears (n = 1612), females with cubs (n = 197) and subadults (n = 126). Using a von Mises circular kernel density estimation procedure, we estimated the overlap of activity for each bear group type relative to humans observed on our cameras (n = 932 encounters; all researchers). All bears avoided peak times of human activity, but socially-subordinate subadults exhibited significantly higher overlap with humans (23 %) as compared to females with cubs and single adults (11 % and 12 %, respectively). Furthermore, subadult bears increased their overlap with human activity over the course of each sampling year, while females with cubs and single adults generally decreased their overlap. These results highlight that the effects of human-disturbance on large carnivores can be complex and may allow for increased foraging opportunities for socially subordinate, but more human-tolerant, individuals.

Context: Dingoes and hybrid domestic dogs (wild dogs) are lethally managed, principally by large-scale baiting programs, to protect Australia's AU$11.4 billion beef cattle industry from predation. This strategy is promoted by pest management agencies as best practice. Aim: To investigate the impact of baiting frequency and rainfall on percentage fetal and calf loss. Methods: Using 64 property-years of data from 31 properties located across Queensland and the Northern Territory, 14 171 mating outcomes were investigated to assess whether annual rainfall, relative to 124-year mean annual rainfall, and the frequency that wild dogs were lethally controlled on each property, influenced predicted fetal and calf loss. Key results: No effect of baiting frequency on fetal and calf loss in mature cows was observed. Predicted fetal and calf loss was significantly higher in dry and very wet years than in moderate-rainfall years (P < 0.001). Losses were observed to be higher in first-lactation cows when baiting was either: not conducted, conducted every 2–5 years or several times per year (P < 0.05) when compared with baiting annually, suggesting that factors other than baiting frequency are likely to have a stronger impact on calf loss. Conclusions: Only limited empirical evidence was found to support lethal control. Further investigations may clarify whether the calves of first-lactation cows experience increased predation risk and whether the effect that dry conditions have on cow nutrition, milk supply and, consequently, the vigour of the cow and calf, may also increase predation risk. Implications: Lethal control of wild dogs to protect calves is mostly unnecessary. We examined fetal and calf loss on 31 properties from 14 171 mating outcomes in relation to baiting frequency and rainfall and found that higher losses occurred in dry and very wet years than in moderate-rainfall years, but there was no association between baiting frequency and percentage fetal and calf loss. Only limited empirical evidence was found to support the lethal control of wild dogs [ABSTRACT FROM AUTHOR]