Search Results (178)

[Objective] To determine the control potential of Arma chinensis against major soybean pests Helicoverpa armigera and Spodoptera exigua, thereby providing theoretical and practical support for biological pest control in soybean fields. [Methods] Laboratory and field experiments were conducted to assess the predation capacity, feeding preference, and field control effect of third~fifth-instar nymphs and male/female adults of A. chinensis on first, third and fifth-instar larvae of these two pests. Predation functional responses were fitted to analyze predation characteristics and the relationship between searching efficiency and prey density. [Results] Both nymphs and adults of A. chinensis preyed on the larvae of H. armigera and S. exigua, with the predation functional responses conforming to the Holling Type II disk equation, which presented the highest predatory efficiency. The female adult of A. chinensis showed strong predation capacity against H. armigera (55.368) and S. exigua (50.699) larvae, with the highest daily prey consumption of 13.158 and 13.699 individuals, respectively. Searching efficiency of A. chinensis was negatively correlated with prey density, and significantly higher for first-instar than third-instar larvae. Under cooccurrence conditions, A. chinensis displayed an obvious feeding preference for H. armigera larvae. Field trials demonstrated that female adults of A. chinensis generated a 70% population decline rate of H. armigera. Meanwhile, the population decline rate of S. exigua reached over 80%. Female adults of A. chinensis achieved field control rates of 80% against H. armigera larvae and 70% against S. exigua larvae. [Conclusions] A. chinensis has strong predation and control potential against the larvae of H. armigera and S. exigua. Among these, females of A. chinensis demonstrated the highest efficacy in controlling the two types of Lepidoptera larvae, both indoors and in field conditions. It is a promising biological control agent for soybean fields and provides a scientific basis for large-scale application. Full article

Introduction: The physical characteristics of microplastics (MPs), particularly their size and color, closely resemble natural food prey for several marine organisms, leading to active or accidental ingestion by marine species, including fish larvae. Despite growing concern, the occurrence of MPs in wild fish during early developmental stages remains insufficiently documented, and laboratory studies report inconsistent results. Given their key ecological role in marine food webs and their economic relevance, the health and survival of fish larvae are critical for maintaining fish populations. Objective: This study aimed to investigate MPs’ presence throughout the larval developmental stages and assess whether MP contamination profiles (concentration, color, type, and size) differ between species. Methodology: MPs were analyzed in the larval stages of two fish species with distinct ecological niches: the European sardine (Sardina pilchardus), a marine migratory species, and the common goby (Pomatoschistus microps), an estuarine resident species. Samples were collected from the Douro Estuary (NW Portugal) over one year, covering different developmental stages. Results: MPs were detected in both species at all developmental stages observed, including the yolk-sac stage (where the feeding of larvae is endogenous), indicating contamination at a stage when the mouth is not yet functional. Sardina pilchardus showed a higher abundance of transparent nylon fibers of 0.5 mm, and Pomatoschistus microps transparent polypropylene fibers of size 0.4 mm. Moreover, MP contamination did not vary between species or throughout the developmental stages, showing similar levels and profiles of MPs contamination. Conclusions: These findings provide new evidence that MP contamination begins at the earliest developmental stages of the fish, from hatching onwards. The results further suggest that MP uptake in fish larvae is primarily driven by environmental availability rather than fish larvae’s preferences or ecological guild, physical characteristics, or even the ontogenetic developmental stage. Full article

Little is known about the vertical distribution of microplastics (MPs) in deep stratified lakes. This study investigates the MPs in the large and deep Lake Trichonis during the thermal stratification period, using two nets of different porosity (50 μm and 200 μm) in three depth strata. Fibers dominated over fragments with an average abundance of 10.63 ± 1.00 items m⁻³ and 3.10 ± 0.52 items m⁻³ respectively in the samples of the 50 μm net in the entire water column, while the respective values for the 200 μm net were 1.4 and 7.4 times greater. Fibers had the highest abundance within the thermocline, and most of them were blue with a length 1–2 mm. There were only abundance differences between the two nets and no qualitative disparities concerning color, size, shape and polymer types. There was a strong positive correlation between the abundance of fibers and the adults of the dominant copepod Eudiaptomus drieschi, which also accumulated within the thermocline. Considering that the adults of E. drieschi are among the preferred prey of Atherina boyeri, the most important commercial fish, certain issues arise concerning possible fiber bioaccumulation on the food web. The study highlights the importance of investigating MPs in connection with biotic elements. Full article

Balancing of macronutrient intake assumes that animals change their food preferences to increase consumption of the deficient nutrients and/or decrease consumption of nutrients in excess. Harvestmen are generalist predators that consume mostly soft-bodied insects, but they supplement this with plant-derived food such as berries (omnivory). In spite of this, they are often carbohydrate-limited in their natural habitats. As aphids have higher sugar content than most other insect prey, they are a potential source of sugar. We hypothesized that sugar-deficient harvestmen have increased preference for aphids relative to other insect prey (fruit flies) and consume more aphids than sugar-satiated harvestmen. Likewise, we hypothesized that protein-deficient harvestmen would show increased consumption of aphids relative to a pure sugar source (dried grape pulp). The former hypothesis was confirmed but the latter was not. Carbohydrate-deprived harvestmen (Leiobunum gracile) consumed 1.9 times more aphids than nutritionally balanced ones (p = 0.0004). Consumption of dried grape was increased in carbohydrate-deficient harvestmen, while protein deficiency did not increase consumption of aphids. These results indicate that aphids may be used as a carbohydrate source if no better alternative is available, but they are unable to relieve a deficiency in protein. We suggest that carbohydrate deprivation in predators may enhance aphid control. Full article

We conducted experiments to assess the importance of the effects of interactions between individuals of co-occurring species, the Common Gudgeon Gobio gobio, native to Europe, and the invasive Monkey Goby Neogobius fluviatilis. We examined the influence of the size of the competitor and the temperature of the water on competition for food between these two species. To investigate whether this food competition is dependent on the size of invasive competitors, we used three size classes of the invasive N. fluviatilis and a single size class of the native G. gobio in a tank-based experiment. To reflect the possible impact of temperature, we used two different water temperatures: 16 °C preferred by the G. gobio and 22 °C preferred by the N. fluviatilis. Based on the number of prey consumed, time to start feeding, and the total time spent hunting prey, we provided direct confirmation that the invasive N. fluviatilis in Europe is the superior competitor for food at both tested temperatures, eating twice as much prey, feeding 2–4 times faster, and spending up to three times more time on hunting. Food competition was size-dependent: the greater threat for native species is invasive fish, which are smaller or similar to them in size. Warmer temperatures (22 °C) gave more than twice as much advantage to the invaders under all tested feeding parameters. Therefore, we concluded that populations of invasive N. fluviatilis present a serious threat to native European benthic fish species (i.e., G. gobio). Increasing temperatures, better tolerated by invasive species, compound this problem. Full article

Microplastic pollution is a pervasive and ecologically significant threat to aquatic systems. Zooplankton, as key mediators of energy transfer and carbon cycling, are particularly vulnerable to microplastic ingestion due to size overlap with natural prey. This systematic literature review synthesises 250 peer-reviewed studies on zooplankton–microplastic and nanoplastic interactions, identified through a Web of Science search (403 initial records, 2012–2026) and screened using Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Bibliometric and narrative thematic analyses were conducted to evaluate publication trends, taxonomic coverage, biological endpoints, experimental design, particle characteristics, and geographic distribution. Publication output increased rapidly after 2019, with nanoplastics emerging as a major research focus. The literature is strongly biassed toward model organisms such as Daphnia magna and Artemia salina, with limited representation of marine taxa. Ingestion and oxidative stress are the most studied endpoints, while trophic transfer, carbon flux, and multi-stressor interactions remain underexplored. Reported experimental designs are predominantly laboratory-based and frequently employ supra-environmental concentrations and simplified particle types. A major geographic gap is identified for the Black Sea, with minimal coverage and no data for dominant regional species. Future research should prioritise ecologically realistic conditions, broader taxonomic and geographic representation, and integrated multi-stressor approaches to support ecosystem-based management. This review characterises publication patterns and knowledge gaps; it does not constitute a formal evidence synthesis, and frequency distributions reflect research coverage rather than strength of evidence. Full article

Human disturbances, such as habitat destruction and overharvesting, are greatly harming ecosystems and causing significant declines in biodiversity. Although protected areas play a crucial role in conserving terrestrial mammals, nearly non-protected areas (N-PAs) have similar functions, harbor high biodiversity and ecosystem integrity, and deserve to be protected. To identify the conservation value of mammalian species in critical ecosystems within N-PAs, we conducted a camera-trap survey in Luolong County, Tibet, from November 2019 to June 2023, monitoring 159 sites and documenting 25 mammalian species across 28 similar or dissimilar habitats. We found this area was an integrity ecosystem with higher species richness and diversity in scrub and evergreen forests with notable occurrence of herbivores comprising musk deer, chinese serow, woolly hares and carnivores such as the common leopard, snow leopards, red foxes and stone marten. Mammalian species occurrence increased away from human activities. Different habitats and seasons influenced diversity and species interactions. Key findings include species preferences for specific habitats, such as blue sheep on southern slopes during snow, musk deer in mixed forests, and red foxes avoiding alpine meadows. Habitat type, elevation, and human disturbance significantly impacted species distribution and behavior. The study also found that snow leopard activity time negatively correlates with woolly hare, while common leopards are influenced positively by hares and negatively by brown bears. Red foxes are slightly more active near the chinese serow occurrence areas. Other predators and prey, such as eurasian lynx, gray wolves, musk deer and stone martens show specific seasonal and interspecific interactions, with some relationships explaining small portions of variation. Overall, species temporal detection events are interconnected through complex ecological interactions. These findings improve our understanding of habitat hosting for rare species and the balance of endangered prey and predator communities in N-PAs in Tibet, emphasizing their significance for conservation efforts. Full article

Mycoplasmas are frequently recovered from the upper respiratory tract of birds of prey, yet many isolates remain taxonomically unresolved. In the present study, a collection of ten previously unclassified Mycoplasma strains, predominantly isolated from the trachea of the common buzzard (Buteo buteo), was subjected to comprehensive phenotypic and genomic characterization. All strains grew well in modified Hayflick’s medium and formed colonies with the characteristic fried-egg appearance. None of the strains produced acid from glucose or hydrolyzed arginine or urea. Phylogenetic analyses based on 16S rRNA gene, 16S–23S intergenic spacer, and partial rpoB gene sequences placed the strains within the Mycoplasma synoviae cluster, in close proximity to five recently described Mycoplasma species associated with raptors such as eagles and kites. Matrix-assisted laser desorption ionization–time of flight (MALDI-ToF) mass spectrometry enabled the clear discrimination of the investigated strains from closely related taxa. Whole-genome comparisons, together with phylogenomic analyses, supported the assignment of these strains to a novel species within the genus Mycoplasma. The name Mycoplasma tracheobuteonis sp. nov. is proposed, corresponding to its preference for colonizing the upper respiratory tract of the common buzzard, with strain 48589B^T (=DSM 115882^T = NCTC 14927^T) designated as the type strain. Full article

Immature ladybeetles and lacewings can thrive by feeding on eggs of lepidopteran pests, such as Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae). However, considering that the survival and fitness performances of generalist predators are heavily dependent on their ability to select suitable prey, we first evaluated whether eggs of S. frugiperda strains with differential susceptibilities to Bacillus thurigiensis (Bt) toxins would affect the food preference of larvae of the ladybeetle Coleomegilla maculata DeGeer (Coleptera: Coccinellidae) and the lacewing Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae). We further determined, for the first time, the functional responses of all immature phases of both predator species when fed with S. frugiperda eggs. In our choice bioassays, predator larvae were individually offered 25 eggs of each S. frugiperda strain. The number of consumed eggs was recorded hourly and replenished during each evaluation. For the functional responses, increasing densities of S. frugiperda eggs were offered to the larvae of lacewings and ladybeetles, and the number of consumed eggs was recorded 24 h after the release of the predator. Ch. externa larvae had a generalized preference for Bt-susceptible strains of eggs, while Co. maculata exhibited such a preference only during the first evaluation hour. Both predators displayed type II functional responses, and their consumption substantially increased during larval development. By demonstrating that lacewing and ladybeetle larvae can satisfactorily consume S. frugiperda eggs, including eggs from Bt-resistant individuals, our findings reinforce the potential of these predatory insects for the ecological management of S. frugiperda. Full article

Predators can exploit chemical signals of social insects to locate prey. Ants are considered as major predators of termites, and the interactions between them have been shaped by a long evolutionary history. Here, we investigated whether the ant Odontoponera transversa exhibits differential responses towards three termite species: Coptotermes formosanus, Ancistrotermes dimorphus, and Macrotermes barneyi. Through a combination of field trapping experiments and laboratory behavioral assays, we found that O. transversa showed stronger predatory responses towards A. dimorphus and M. barneyi than towards C. formosanus. Furthermore, when A. dimorphus or M. barneyi was present, attacks on C. formosanus were rarely observed, suggesting a hierarchy in prey preference. Behavioral assays indicated that termite trail pheromones serve as key cues influencing ant foraging decisions. Our findings suggest that differential responses to chemical signals, particularly trail pheromones, may underlie the observed prey preference patterns in O. transversa. Together, these results demonstrate that chemical signals, particularly trail pheromones, are key determinants of prey preference in O. transversa, offering a foundation for understanding the chemical ecology of ant–termite interactions. Full article

Plant volatiles are critical mediators of insect–plant interactions, guiding natural enemies to specific habitats and prey. The flower bug, Orius maxidentex Ghauri (Hemiptera: Anthocoridae), is a generalist predator that exhibits a specialized ecological association with the weed Celosia argentea L. (Caryophyllales: Amaranthaceae), utilizing the plant as a primary floral niche in Hainan Island. In this study, the attractiveness of C. argentea floral volatiles to O. maxidentex was confirmed using a Y-tube olfactometer. Solid-phase microextraction (SPME) combined with gas chromatography–mass spectrometry (GC-MS) was utilized to identify six compounds in the floral volatiles: 1,3-diethenylbenzene, trans-cinnamaldehyde, β-bisabolene, methyl salicylate, 3-ethylbenzaldehyde, and nonanal. Electroantennogram (EAG) assays revealed that O. maxidentex antennae showed significant physiological responses to these compounds, and the EAG relative values were positively correlated with concentration gradients. Furthermore, O. maxidentex exhibited significant orientation responses to 1,3-diethenylbenzene, trans-cinnamaldehyde, β-bisabolene, and methyl salicylate, whereas no behavioral response was observed for 3-ethylbenzaldehyde or nonanal. Further tests revealed that β-bisabolene elicited the highest attractiveness, comparable to a synthetic blend formulated to mimic the natural release ratio of the active semiochemicals. These findings reveal the hidden chemical cues mediating the interaction between a predator and its preferred habitat. Understanding this mechanism not only helps explain insect adaptation but also offers new strategies for using these plant volatiles to influence the behavior of this specific predator, potentially enhancing its targeted recruitment in agroecosystems. Full article

Outbreaks of crown-of-thorns sea stars (CoTS) threaten coral reef integrity and biodiversity, yet local dynamics and short-term responses to control remain insufficiently described. This study characterised an outbreaking Acanthaster population in two specific sites of the coast of Khor Fakkan (Gulf of Oman, United Arab Emirates) to resolve species identity, population composition, prey selection and the effects of targeted removals. All sequenced individuals clustered in two related haplotypes belonging to the species Acanthaster planci. Benthic surveys showed moderate live-coral cover, dominated by massive Porites sp. colonies. Moreover, the observations of 139 preyed colonies revealed pronounced genus-level selectivity, with branching and complex morphologies suffering disproportionately and massive forms largely avoided. However, the selection of massive Plesiastrea and Favites genera as preferred coral prey might suggest a shift towards less preferred coral in the CoTS diet, posing a severe threat to coral reefs’ integrity. Intensive removal reduced the local density, up to 86%, and provided substantial short-term relief, but continued monitoring is required to secure long-term reef resilience. Full article

In healthy ecosystems, large raptors such as the White-tailed Eagle perform the essential roles of predators, bioindicators, and umbrella species. Despite their importance, many species of raptors are globally endangered, and similarly, in the Republic of Moldova, 13 species of diurnal birds of prey went extinct in the last 7 decades. The White-tailed Eagle (Haliaeetus albicilla) is the only example of a raptor that has regionally made a demographic and distributional comeback after decades of absence. Following this comeback, a national monitoring scheme during 2014–2025, including a nest counting survey in 2022–2024, has been implemented to understand what the current national situation of the species is and its ecological preferences and threats, together with the fundamental ecological context that allowed the breeding population to adapt to an ever-changing landscape. Field research conducted over 12 years confirmed the breeding of eight pairs, with data indicating a minimum of 19–23 nesting pairs. Pairs generally avoid human-dominated landscapes, preferring higher coverage of wetlands and forests, but current data suggests frequent occupancy of suboptimal territories and increasing tolerance towards human activity and infrastructure. Although currently small, the breeding population experiences high breeding success with no negative outcomes recorded. However, droughts and forestry activities in the proximity of the nests potentially reduced and delayed breeding success. Current forestry and fish farming practices increase the vulnerability of the few known breeding pairs to habitat degradation, poaching, and deforestation. To improve the conservation status of this endangered raptor in the Republic of Moldova, as close as possible to Least Concern status, it is crucial to implement multi-purpose buffer zones around active nests during the breeding season and to further survey the breeding population and assess any demographic trends. Full article

Pomacea canaliculata, a pervasive invasive gastropod, inflicts significant ecological and economic damage in Chinese rice ecosystems. With the limitations of chemical molluscicides, sustainable biological control solutions are urgently required. This study presents a comprehensive investigation into the biocontrol potential of larvae of the endemic aquatic firefly, Aquatica leii, against Pomacea canaliculata. Through controlled laboratory experiments, we evaluated the feeding preference of larvae when offered a choice between Pomacea canaliculata and a native snail (Cipangopaludina chinensis), and systematically quantified the predatory efficiency (lethal time and consumption amount) across the 3rd to 6th larval instars. Furthermore, the lethal activity of crude extracts from distinct anatomical regions of the larval digestive tract (mouthpart, foregut, midgut, and hindgut) was assayed via injection into Pomacea canaliculata. The larvae accepted Pomacea canaliculata as a viable prey source. Predatory performance varied markedly among instars; 4th-instar larvae exhibited optimal efficacy, characterized by the shortest mean lethal time (7.37 min) and the highest mean consumption (1.23 g). Midgut extract was identified as the principal causative agent of mortality, inducing a 96.7% mortality rate in Pomacea canaliculata, which was significantly superior to the minimal effects observed from other extract types. This points to the midgut secretion as a likely source of potent bioactive compounds responsible for rapid snail lethality, warranting further investigation. responsible for rapid snail lethality. Our results conclusively demonstrate, from both behavioral and physiological vantage points, the feasibility of Aquatica leii larvae as a highly effective native biocontrol agent. This work establishes a critical foundation for future research aimed at the isolation and characterization of the midgut-specific active substances, paving the way for the development of novel, target-selective biogenic molluscicides. Full article

Long-eared Owls (Asio otus) overwinter in groups, mainly on coniferous trees in human settlements. These owls regurgitate the indigestible parts of their prey as pellets. Analysis of pellet contents provides valuable information on diet composition and reflects the characteristics of the hunting area. We assumed that prey availability for owls is influenced by the extent of built-up areas and by the distribution of habitats around the roosting site. In the winter of 2016/2017, we collected three samples of 1000 pellets from settlements in the southern part of Hungary: the village of Udvar, the town of Mohács, and the city of Pécs. Species accumulation curves were calculated based on cumulative prey species richness and rarity. To assess the effect of built-up areas, we compared the diet composition of owls wintering in settlements of different sizes. To estimate the size of the hunting area, we compared the relative abundance of small mammal species with different habitat preferences detected in the pellets with the proportion of habitat type within circles of one, two, and three kilometres around the roosting sites. The proportion of open and forested habitats decreased as the extent of built-up areas increased. This reduced access to the owls’ main prey, especially Common Voles (Microtus arvalis) and other small mammals. As a result, the minimum number of pellets needed for a representative sample was at least 300 in the village, 600 in the town, and 1000 in the city. In the city, owls showed higher prey species richness, greater diversity, higher evenness, and a wider food niche than owls in the town or village. In the village, the relative abundance of small mammal species associated with urban, open, forested, or wetland habitats in the owl diet fully matched the distribution of these habitat types within a three-kilometre radius around the roosting site. In the town, such matching was found only for open and forested habitats. In the city, this relationship was observed only for wetland habitats. Pellet analysis of wintering Long-eared Owls can reveal the impact of land use on small mammal prey communities and highlight important ecosystem services of this owl species, including its role in reducing small mammal pests. Full article