Search Results (109)

Insects exhibit a range of ecological relationships with plants, including pollination, seed dispersal, parasitism, predation, and herbivory. Interactions between insects and plants are shaped by internal daily timekeeping systems in both sets of organisms termed circadian clocks. This review describes the impact of the circadian clocks of insects and plants on herbivory, which is highly relevant not only to natural ecosystems, but also to agriculture and forest management. Following an introduction to the circadian clocks of plants and insects, we discuss the circadian organization of relevant aspects of plant metabolism and defense. Next, we describe how insect clocks govern herbivory-associated physiology and behavior before exploring how rhythmic processes in plants and insects interact to temporally control herbivory. Finally, we describe how insights from the clock control of herbivory may inform pest management strategies and what future research in this area may contribute. Full article

The red fox (Vulpes vulpes) is a widely distributed and highly adaptive small carnivore known by its generalist diet, which includes small mammals, invertebrates, and fruits. Despite its ecological relevance, how habitat heterogeneity affects its diet across the Mediterranean, a biodiversity hotspot shaped by long-term human disturbance, remains insufficiently synthesized. In this review, we synthesized and analyzed published studies that reported habitat-specific data on the red fox diet in the Mediterranean. Only 12 studies met the selection criteria, and no study directly compared two different habitats. The studied areas covered three dominant habitats: forests, scrublands (garrigue), and agroecosystems, and diet items were grouped in 7 categories: birds, carcasses, fruits, invertebrates, lagomorphs, small mammals, and reptiles. Overall diet composition varied significantly, with invertebrates and fruits being the most frequent diet items. In turn, lagomorphs and reptiles were the least frequent. In turn, diet composition varied little across habitats, indicating that diet variation follows specific local resource abundance regardless of habitat type. Despite the analytical limitations associated with the limited availability of habitat-explicit studies. The results highlight the pronounced dietary plasticity of the red fox and its capacity to integrate resource availability across heterogeneous Mediterranean landscape mosaics. This trophic adaptability and top predator role support various ecosystem functions such as controlling invertebrate and small mammal populations, dispersing seeds, and cycling nutrients, reinforcing the potential of the red fox as functional bioindicator in the Mediterranean. Therefore, sustainable land management, especially in agricultural areas, and restoration efforts for degraded areas should consider the beneficial roles of generalist carnivores like the red fox. Full article

Insect pollination, a critical ecological process, pre-dates the emergence of angiosperms by nearly 200 million years, with fossil evidence indicating pollination interactions between insects and non-angiosperm seed plants during the Late Paleozoic. This review examines the symbiotic relationships between insects and gymnosperms in pre-angiosperm ecosystems, highlighting the complexity of these interactions. Fossil records suggest that the mutualistic relationships between insects and gymnosperms, which facilitated plant reproduction, were as intricate and diverse as the modern interactions between angiosperms and their pollinators, particularly bees. These early pollination systems likely involved specialized behaviors and plant adaptations, reflecting a sophisticated evolutionary dynamic long before the advent of flowering plants. The Anthropocene presents a dichotomy: while climate change and anthropogenic pressures threaten insect biodiversity and risk disrupting angiosperm reproduction, such upheaval may simultaneously generate opportunities for novel plant–insect interactions as ecological niches are vacated. Understanding the deep evolutionary history of pollination offers critical insight into the mechanisms underlying the resilience and adaptability of these mutualisms. The evolutionary trajectory of bees—originating from predatory wasps, diversifying alongside angiosperms, and reorganizing after mass extinctions—exemplifies this dynamic, demonstrating how pollination networks persist and reorganize under environmental stress and underscoring the enduring health, resilience, and adaptability of these essential ecological systems. Full article

Florivory is the consumption or damage of flowers by herbivorous animals. It can directly affect plant fitness by damaging reproductive organs or indirectly by negatively influencing flower attractiveness to pollinators. We investigated florivory in field bindweed Convolvulus arvensis L. (Convolvulaceae) by combining data from natural surveys, experimental damage, and laboratory experiments on flower preferences of florivores. Surveys showed that flowers suffer damage from predators, including Leptophyes albovittata Kollar (Orthoptera: Tettigoniidae), which causes partial corolla damage, and from unknown predators that cause holes in the corolla. Experimentally damaged flowers had significantly lower reproductive success (number of seeds and proportion of total reproductive failure) than intact flowers. However, laboratory experiments with naïve bumblebees Bombus terrestris L. (Hymenoptera: Apidae) failed to detect a preference for undamaged flowers. This may be because B. terrestris is not a frequent pollinator of C. arvensis at our field sites, and naïve foragers, lacking prior experience, had not learned to associate corolla damage with reduced floral rewards. Our research shows that florivory negatively impacts C. arvensis reproductive success by altering pollinator behavior through reduced flower attractiveness. Full article

Habitat fragmentation profoundly alters ecological processes such as seed predation and dispersal. Ants play a central role as seed removers and dispersers, yet the effects of fragmentation on seed-carrying ant assemblages in dry tropical forests remain insufficiently studied. In this work, we examined the influence of forest fragmentation on seed-carrying ants in the Chaco forests of central Argentina. Ants were sampled across nine forest fragments of varying sizes and two continuous forests within an agroecosystem landscape, and species richness, composition, and occurrence were analyzed. Our results revealed that species richness did not vary significantly with fragment size; however, fragmentation caused pronounced shifts in species composition, with clear distinctions between continuous forests and fragments. Large-bodied specialist harvester ants declined in fragments, whereas small- to medium-sized generalist species from genera such as Pheidole and Solenopsis persisted. These compositional changes suggest that although overall seed removal rates may remain stable, the functional quality of seed dispersal likely diminishes. This study highlights the sensitivity of seed-carrying ant assemblages to habitat fragmentation and underscores the need for further research that integrates behavioral and landscape-scale approaches to better assess impacts on seed removal, dispersal, and forest regeneration in fragmented dry forests. Full article

The Pampas fox (Lycalopex gymnocercus) is a widespread meso-predator in Southern South America, present in grasslands, agroecosystems, and human-modified landscapes. Although numerous studies have examined its diet, parasites, distribution, and behaviour, knowledge remains fragmented without an integrative synthesis. This review compiles over 150 documents from Argentina, Uruguay, Brazil, Paraguay, and Bolivia to unify dispersed information. Key findings highlight unresolved taxonomy, population structure, and biogeography (based on genetic, morphological, and phylogeographic data), the species’ ecological roles as a meso-predator, seed disperser, and scavenger, and major threats (including road mortality, hunting, persecution, and interactions with domestic dogs). The Pampas fox also harbours pathogens—including zoonotic agents and those threatening livestock and pets—and is frequently stigmatised as a pest, persecuted without substantiated evidence. By integrating ecological, health, and conflict perspectives, this review provides a regional baseline, reframing its importance and guiding more effective management. Full article

This essay confronts a classic tension: Christian tradition has long linked death in the world to human sin, yet evolutionary science reveals eons of predation, pain, and extinction preceding the emergence of Homo sapiens. In this essay, it is asked whether and how this history can be reconciled with belief in a good creation by the God who is love. After situating the stakes of this question with regard to evangelization, I examine Jesuit physicist Richard Pendergast’s ambitious proposal that fallen angels reshaped the material order and thereby seeded natural evil throughout evolutionary time. I set this account in critical conversation with major figures of the Christian tradition, including Augustine, but especially Joseph Ratzinger (Benedict XVI) and Thomas Aquinas, who—while upholding the fall and the need for redemption—locate suffering and death within natural order of creation and compatible with the divine goodness rather than as anomalies. It will be seen that Ratzinger, for his part, proposes a way to preach and live a “creation and evolution” synthesis in which the cross and resurrection illuminate, rather than erase, the hard facts of biological history. The essay concludes by assessing the metaphysical feasibility, scientific plausibility, and theological fittingness of attributing foundational and large-scale natural processes to angelic causation, noting that it risks dualism and the eclipse of creation’s fundamental goodness. Full article

Invasive seed predators can severely affect the reproduction of long-lived trees, especially when host range expansion occurs. The beetle Specularius impressithorax (Chrysomelidae: Bruchinae), native to Africa, has become established in Hawaiʻi where it attacks the endemic coral tree (Erythrina sandwicensis; Wiliwili). Here, we report the infestation of an African coral tree (E. livingstoniana) by this beetle and assess its performance and oviposition patterns on native and non-native hosts. Field surveys showed that eggs were aggregated on both hosts but more abundant on E. sandwicensis than on E. livingstoniana. Laboratory assays revealed no difference in larva-to-adult survival between the two hosts, although adults emerging from E. sandwicensis were larger. Choice tests indicated no oviposition preference between the two Erythrina species, despite the larger seed size of E. sandwicensis. To explore potential host range expansion, trials were run on economic legumes with varying phylogenetic distance from Erythrina, which showed oviposition on peanut (Arachis hypogaea) with low but successful survival (10.3%), while no development occurred on broad bean or pigeon pea. More E. sandwicensis seeds germinated when infested by a single early-stage larva (70% germination) than when uninfested (20%), suggesting that minimal seed predation may facilitate germination because previously reported greater damage induced by infestation through adulthood reduces germination. Our findings highlight the ecological flexibility of an invasive bruchine, its potential to exploit other Faboideae plants, and the dual role of seed predators as both threats and facilitators of seed germination. These results have implications for conservation of endemic coral trees and for understanding invasion dynamics of shared seed predators. Additionally, we examined non-botanical substrate filled with seed powder for oviposition and compiled global host records of S. impressithorax to contextualize its host range expansion. Full article

Polycomb Group (PcG) proteins, particularly E(z) (Enhancer of Zeste) genes, play essential roles in transcriptional repression and developmental regulation. To investigate their evolutionary history, we conducted a comprehensive comparative genomic analysis of E(z) homologs across green plants. Phylogenetic analysis revealed that E(z) genes are highly conserved, predominantly occurring as single copies in green algae and early land plants. In seed plants, however, E(z) homologs diverged into two major clades, CLF and SWN, likely originating from an ancient duplication predating seed plant diversification. Conserved domain and motif analyses showed that while all E(z) proteins contain the hallmark SET domain, certain lineages also harbor CXC and SANT domains. Moreover, lineage-specific motif divergence was observed, suggesting functional diversification. In angiosperms, further duplications shaped the SWN lineage: in Brassicaceae, SWN genes split into SWN and MEA subclades, whereas in Fabaceae, SWN genes diverged into SWN1 and SWN2. Structural comparisons revealed that both Brassicaceae MEA and Fabaceae SWN2 proteins independently lost approximately 200 amino acids in the central region, indicating convergent structural modifications. Molecular evolutionary analysis showed that Fabaceae SWN1 genes are under purifying selection, consistent with retention of ancestral functions, whereas SWN2 genes experienced strong positive selection, implying functional innovation. Expression profiling of soybean E(z) genes further supported this scenario: SWN1 is broadly expressed across tissues, while SWN2 expression is restricted to the heart-shaped embryo. This pattern mirrors Arabidopsis MEA, suggesting that Fabaceae SWN2 may have evolved imprinted gene functions critical for seed development. Together, our results highlight the evolutionary conservation of E(z) genes in plants and reveal how gene duplication and lineage-specific divergence have driven functional specialization, particularly in Fabaceae SWN2. Full article

Background/Objectives: As crucial natural predators, hornets contribute to ecosystem function by preying on agricultural and forest pests and facilitating plant pollination. However, the predatory preference of hornets for honeybees poses a significant threat to honeybee pollination and the development of the beekeeping industry. Foraging and pollination behaviors in hornets are largely governed by a sensitive olfactory system, but their olfactory molecular mechanisms remain poorly understood. Methods: VvelCSP1 and VvelCSP4 were successfully expressed in the prokaryotic expression system and purified by Ni-NTA affinity chromatography column. Fluorescence competitive binding assays were employed to evaluate their binding affinities to volatile compounds derived from the seed elaiosome of Stemona tuberosa and honeybees. Molecular docking was further performed to analyze key residues and interaction patterns within the binding pockets. Results: Fluorescence competitive binding assays showed that both proteins prefer long-chain alkanes yet exhibit significant substrate selectivity and high ligand specificity. VvelCSP1 specifically binds to hexacosane, while VvelCSP4 specifically recognizes docosane. Molecular docking results demonstrated that the binding process between VvelCSP1, VvelCSP4 and their respective ligands is dominated by hydrophobic interactions. Conclusions: This study provides functional evidence for investigating the olfactory molecular regulation mechanisms underlying hornet-mediated seed dispersal. These findings establish a foundation for potential applications of hornets in plant propagation, biological pest control, crop pollination and ecological balance maintenance in agroforestry systems. Full article

Insect pre-dispersal seed predators attack a large proportion of the acorn crops in oak forests worldwide. Oaks (Quercus spp.) have evolved several strategies, including physical barriers, chemical defenses (e.g., tannins), and/or phenological predator avoidance, to reduce infestation rates. This study examines how four Mediterranean oak species cope with acorn-feeding insects. Nearly 4000 acorns were collected from five sites at two time points during the maturation period: in mid-September and mid-October. Infestation rates were higher in mid-September, when the pericarp is softer and easier to drill, but at that time, the cotyledon tannin content was higher. Q. coccifera acorns had the highest tannin concentration, which, we experimentally discovered, hampered weevil development (with longer development and a lower final larval mass). Infested acorn abscission was also more effective in Q. coccifera. Due to the smaller size and later maturation phenology of its acorns, insects depleted the cotyledons and suffered food shortages more frequently. In the end, Q. coccifera showed the lowest acorn infestation rates, although its strategy would have costs in further stages of the regeneration cycle. Tannins deter acorn dispersers, and their production is costly. Such trade-offs would favor the co-existence of different strategies evolved by Quercus spp. against pre-dispersal insect predators. Full article

Environmental changes may affect animal hoarding behavior through changes to plant diversity. Food hoarding behavior in small mammals can affect the seed dispersal process and thus the regeneration of the plant population. However, little is known about how small mammals select seeds of different sizes under different forest types. Here, we tracked the fates of 3360 seeds in the field. We used a generalized linear mixed model to analyze the effects of small mammals on three fates (predation in situ, predation after dispersal, hoarding after dispersal) and two dispersal distances (predation distance after dispersal and hoarding distance after dispersal) of different seeds by size and forest type. The results showed that small mammals consume smaller seeds in situ and cache larger seeds after dispersal. The predation distance after dispersal and hoarding distance after dispersal of the large seeds were significantly higher than those of small seeds. Forest types with dense vegetation conditions exhibited lower hoarding rates after dispersal, while those with poor vegetation conditions had increased predation and hoarding distances after dispersal. Our results suggest that larger seeds are dispersed to further distances, potentially enhancing plant population regeneration. However, seeds are more often scatter-hoarded and dispersed over longer distances in forests with poor vegetation conditions, which may also benefit plant population regeneration. These results provide insights into how seed size and forest type influence seed predation and dispersal by small mammals. Full article

Exploring host preference and resource partitioning among seed predator species is essential for understanding the coexistence mechanisms and guiding effective forest pest management. This study aimed to elucidate how seed traits influence infestation dynamics and species interactions, focusing on acorn weevils infesting Quercus mongolica. Species identification and clarification of their evolutionary relationships within the Curculio genus were performed through phylogenetic analyses of the mitochondrial cytochrome c oxidase subunit I gene sequences. The seed infestation patterns were assessed by comparing the infestation rates across various seed size classes. Furthermore, the correlations between the seed morphological traits (length, width, aspect ratio, and weight) and weevil abundance were analyzed. The phylogenetic results revealed well-supported monophyletic clades corresponding to Curculio arakawai and Curculio sikkimensis. This confirmed the clear genetic separation between these two distinct weevil species, thereby substantiating the divergence observed in weevil populations correlated with different seed hosts. The infestation patterns revealed the association of weevil species-specific preferences with seed size: C. arakawai predominantly infested larger acorn seeds, whereas C. sikkimensis predominantly infested smaller acorn seeds. C. sikkimensis favored smaller ones. Both species exhibited positive correlations between abundance and seed length and width in larger seeds; however, the seed weight displayed no significant effect. These results indicate niche differentiation mediated by seed size and morphology, which likely reduced interspecific competition and facilitated coexistence. This study elucidates species-specific host selection patterns in acorn weevils and highlights acorn traits as crucial factors shaping seed predator assemblages. The findings provide valuable insights for developing targeted pest management strategies and supporting sustainable oak forest regeneration. Full article

Small terrestrial mammals (STMs) are vital components of forest ecosystems. They serve as seed dispersers, herbivores, prey, and vectors of pathogens. The STM community structure responds dynamically to forest composition, disturbance, and management regimes. However, despite their central ecological functions and frequent occurrence, STMs remain underestimated. This narrative review aims to comprehensively synthesize existing literature on the reciprocal interactions between STMs, temperate and boreal ecosystems, and forest management. Specifically, we (1) define a group of STMs and their specificities; (2) discuss the influence of forest structure, disturbance, and management on STM populations; and (3) analyze the known direct and indirect effects of STMs on forest ecosystems and forestry. Full article

We report a landscape-scale natural experiment that followed the abundance and demography of forest-floor small mammals and the activity of small mustelids over a 4-year period of an extreme heat wave and abundant coniferous cone crops. Deer mice (Peromyscus maniculatus) and southern red-backed voles (Myodes gapperi) are major species in the coniferous forest-floor small mammal community near Summerland in southern British Columbia, Canada. Their major mammalian predators include the short-tailed weasel (Mustela richardsonii), long-tailed weasel (Neogale frenata), and American marten (Martes americana). We evaluated three hypotheses (H) that may explain the changes in these mammals from 2021 to 2024: (H₁) that large coniferous cone crops in 2022 would have generated high populations of forest-floor small mammals in 2023 owing to enhanced reproductive output and overwinter survival; (H₂) that increased activity of mustelids would have followed population increases, resulting in the decline of small mammal prey in 2024; and (H₃) that the widespread occurrence of cone crops in 2022 would also have elicited the same mammalian responses in 2023 at a second study area (Golden, BC) 276 km and three mountain ranges from Summerland. During the summer periods of each year, small mammal populations were monitored by intensive live-trapping, and mustelid presence was measured via an index of activity based on live traps, fecal scats, and predation events. The mean abundance and reproductive performance of the P. maniculatus and M. gapperi populations increased in response to the coniferous seedfall, thereby supporting H₁. The activity of small mustelids responded positively to increased numbers of small mammal prey and potentially acted in a regulatory and top–down function in these communities, and hence partially support H₂. Similar responses at Summerland and Golden indicated that this seedfall event and changes in the mammalian community occurred at a landscape-scale, thereby providing partial support for H₃. Potential differential effects of large seed crops on consumers did not affect the mean abundance patterns for P. maniculatus but apparently reduced this metric for M. gapperi. Heat waves, induced by anthropogenic climate change, may alter the frequency of coniferous masting events, and their effects may temporarily change the number and species of mammalian seed consumers and their predators. Full article