Search Results (1,574)

Phytoseiid mites (PDMs) utilize both herbivorous prey and an alternative food source in agroecosystems. However, biocontrol screening of PDMs has largely focused on their predation function against prey, with their use of alternative food often ignored. Therefore, in the present study, we compared the performance of three PDM species (Amblyseius largoensis (Muma), Neoseiulus californicus (McGregor) and Neoseiulus barkeri Hughes), fed on two food sources: onion thrips (Thrips tabaci) and pollen (an alternative food) on potato plants. All three PDMs concentrated their attacks on the vulnerable prey stages, with early larval instars attacked at the highest rate, while N. californicus proved the most effective egg predator and N. barkeri the least. A. largoensis located and attacked prey the fastest both in leaf arenas and on intact plants, despite the longest per-prey handling time and attacked the fewest prey across a density gradient while leaving the least thrips-induced leaf damage. Prey rather than pollen was the primary driver of survival in every PDM, and A. largoensis persisted longest under food limitation and was the only species to gain further benefit from pollen when prey was already available. This ranking inverted in mixed-species arenas, where N. californicus consistently outsurvived the other two species under prey-present and pollen-only conditions. Foraging efficiency, food resource use and intraguild dominance were dissociated for PDM performance. Thus, a multiple-trait screening can be considered in PDM selection for thrips management in crops. Full article

Long-term monitoring data provide an opportunity to distinguish between the prevalence of herbivorous insects and the ecological consequences of their activity. Using observations collected in alder stands within the Polish ICP Forests network during 2013–2025, we investigated temporal patterns of insect-related damage, recovery dynamics, and evidence for delayed density-dependent regulation. Damage severity exhibited strong interannual persistence, although transitions toward lower damage classes occurred more frequently than shifts toward higher classes. Ordinal regression analyses identified contrasting effects of infestation prevalence, with positive contemporaneous effects and negative lagged effects on subsequent damage severity. Plot-level analyses revealed negative feedback and convergence towards an equilibrium damage level, supporting the presence of delayed regulatory processes. Infestation prevalence and damage severity remained strongly associated through time, yet damage declined more rapidly following peak infestation, indicating stronger recovery of ecological impact than of occurrence itself. Spatial analyses revealed persistent clustering of damage levels but comparatively weak spatial structure in annual damage change. Overall, the results demonstrate that persistence, recovery, and delayed feedback jointly shape long-term herbivore impacts in alder ecosystems and highlight the value of assessing both infestation prevalence and damage severity in forest monitoring programmes. Full article

Stable-isotope data are widely used to reconstruct ancient diets, but cross-regional comparisons of raw δ¹³C and δ¹⁵N values can be confounded by ecological baseline variation. Using published bone collagen data, we calculated mean isotope values for human, pig, and deer samples within each site–period unit and derived Hominidae–Suidae, Hominidae–Cervidae, and Suidae–Cervidae offsets. Data-driven breakpoint analysis was conducted along chronological, longitudinal, and latitudinal axes, with breakpoint robustness assessed through bootstrap stability and site dominance. Suidae–Cervidae Δδ¹³C and Δδ¹⁵N produced more stable breakpoints than Hominidae–Suidae and Hominidae–Cervidae offsets. Suidae–Cervidae offsets were substantially larger west of 115.66°E than to the east, north of 33.60°N than to the south, and increased after approximately 5.3 ka BP. Joint temporal, longitudinal, and latitudinal analysis showed that the largest offsets occurred among samples located west of 115.66°E and north of 33.59°N. This growing divergence likely reflects increasing differentiation between the diets of settlement-associated pigs and the natural herbivore baseline represented by deer. Potential causes include C4-derived resources, settlement refuse, manured foods, and deliberate feeding. These findings demonstrate that inter-animal isotope offsets can reveal spatiotemporal structures that are less apparent in raw isotope values and provide an additional perspective on changes in animal management and subsistence practices. Full article

Water limitation and herbivore attack frequently co-occur in agricultural systems, yet defense-related biochemical responses under these combined conditions remain difficult to predict, particularly during simultaneous attack by multiple herbivore species. We investigated how defense responses in field-grown tomato (Solanum lycopersicum L.) differed between irrigation environments and according to herbivore species identity and combination. Well-watered and water-deficit plants were exposed to the spider mites Tetranychus evansi and Tetranychus urticae and the tomato leafminer Tuta absoluta, individually or in interspecific combinations involving two or three species. Plants received either 100% or 50% of the estimated crop water requirements, with leaves collected before and after seven days of herbivore feeding. Gravimetric soil moisture was 21.1% in the water-deficit sector and 29.0% in the well-watered sector. Hormonal responses differed between irrigation environments and among herbivore treatments, with significant interactions for abscisic acid (ABA), jasmonic acid (JA), salicylic acid (SA), indole-3-acetic acid (IAA), and zeatin. ABA and SA concentrations were generally higher in the water-deficit environment, whereas JA concentrations were generally higher in the well-watered environment. IAA and zeatin exhibited distinct responses associated with T. urticae infestation under water-deficit conditions. Proline concentrations were generally higher in the water-deficit environment. Simultaneous infestations involving two or three herbivore species were associated with distinct biochemical response patterns, particularly in lipoxygenase (LOX), polyphenol oxidase (PPO), and trypsin inhibitory activity (TIA). Fruit production also differed between irrigation environments, whereas the proportion of fruits damaged by Neoleucinodes elegantalis was similar (29.3% and 30.8% in well-watered and water-deficit environments, respectively). Overall, these findings indicate that tomato hormonal and biochemical responses to herbivory vary with irrigation environment and herbivore community composition, highlighting the context-dependent nature of plant responses to combined abiotic and biotic challenges. Full article

Green roofs are a key component of urban green infrastructure and can support diverse urban biota. However, the effects of global change factors, such as nitrogen (N) deposition, on arthropod communities in green roofs remain poorly understood. We conducted a controlled N addition experiment on an experimental green roof planted with four species. Ground-dwelling arthropods were collected by pitfall traps and identified to the family or genus level. We assigned individuals to functional groups based on feeding habits and analyzed how N addition and plant characteristics affect functional group structure. N addition did not change total arthropod abundance or richness, but it increased predator abundance significantly (p = 0.023) and herbivore abundance marginally (p = 0.060). The interaction between N addition and plant identity affected Shannon–Wiener and Pielou evenness of detritivore arthropods. PCoA and PERMANOVA testing showed that plant identity explained 23.7% of community variation (p = 0.006), whereas N addition was marginal (R² = 7.7%, p = 0.056). Plant characteristics were closely related to the community structure of different functional groups. These results indicate that N addition caused functional group-specific shifts rather than overall diversity loss, and that plant identity was a major driver of ground-dwelling arthropod communities on green roofs. Full article

The acarophagous beetles Parastethorus histrio (Chazeau) (Coccinellidae) and Oligota pygmaea (Solier) (Staphylinidae) are naturally associated with colonies of the avocado red mite, Oligonychus yothersi (McGregor) (Acari: Tetranychidae), in commercial avocado orchards. However, their demographics and responses to plant- and prey-derived cues remain poorly understood. Volatile profiles vary with herbivore density, plant condition, and environment, but early-autumn volatiles from mite-infested avocado shoots and their effects on these predators remain uncharacterised. We evaluated the development, survival, reproduction and fertility life-table parameters of both predators when feeding on O. yothersi. We also characterised volatile extracts from non-infested and mite-infested avocado shoots collected during early autumn and assessed predator responses to plant volatiles, live-prey odours and prey-derived residues in two-choice olfactometer assays. Both beetles completed their development on O. yothersi, with egg-to-adult survival rates of 86.6% in P. histrio and 90.0% in O. pygmaea. Parastethorus histrio developed more rapidly and exhibited greater female longevity, whereas O. pygmaea showed higher daily and lifetime fecundity. Both predators had higher net reproductive rates than the prey, but their lower intrinsic rates of increase and longer generation times indicated slower population growth per unit time. Volatile profiles differed between non-infested and mite-infested shoots, with limonene predominating in extracts from infested plants. Both predators allocated more time to extracts from mite-infested than non-infested shoots. Their responses to prey-derived cues differed: O. pygmaea responded positively to odours from live O. yothersi females but not to colony residues, whereas P. histrio reduced its allocation to both stimuli. These findings reveal contrasting life-history and host-location strategies in the two predators and support further evaluation of their potential as natural enemies of O. yothersi in avocado orchards. Field studies are required to determine whether these traits translate into predator establishment and effective suppression of mite populations. Full article

Tannins are plant-derived polyphenolic anti-nutritional factors that impair nutrient absorption, damage the intestinal barrier, and disrupt metabolic homeostasis. Some animals, however, have an innate resistance to the effects of tannins. Sika deer (Cervus nippon) exhibit strong tolerance to long-term consumption of tannin-rich oak plants, and Akkermansia muciniphila is considered a key functional bacterium, yet the underlying mechanism of this remains unclear. In this study, we transplanted fecal microbiota from tannin-acclimated sika deer into antibiotic-pretreated C57BL/6J mice, followed by tannin gavage to establish a stress model. Growth performance, serum glycolipid indices, and hepatic metabolic gene and protein expression were detected. Results showed no significant differences in body weight, fat deposition, or serum biochemical parameters between groups. In the transplantation group, key genes involved in glycolysis, detoxification, and lipid metabolism were significantly upregulated, while CYP7A1, a bile acid synthesis rate-limiting gene, was significantly downregulated at both transcriptional and protein levels. Akkermansia was specifically enriched in the gut of transplanted mice. In conclusion, the microbiota of the sika deer gut alleviates tannin toxicity and enhances host tolerance by regulating hepatic glycolipid and bile acid metabolism pathways. The results of our study provide new insights into the adaptation mechanisms of herbivores to high-tannin diets. Full article

Perennial crops can provide a shared habitat template for arthropods, but whether regional differentiation persists among fields of the same crop in drylands remains unclear. From 2020 to 2022, we surveyed ground–active beetles at 55 perennial alfalfa sites across mountainous, oasis, and desert regions of Ningxia, China. We compared beetle diversity and feeding–guild structure among regions and examined their relationships with climate, soil, and vegetation. A total of 48,093 individuals representing 105 species, 62 genera, and 10 families were recorded. Agroecological region explained 30.1% of compositional variation and was associated with differences in total assemblages and all guilds. Mountainous sites had higher overall species richness and were dominated by detritivores; oasis sites contained a greater proportion of herbivores despite similar herbivore activity density among regions, whereas desert sites were numerically dominated by carabids and predators but had lower richness and diversity within the predatory guild. Regional differentiation was more evident in richness, assemblage composition, and trophic organization than in Shannon and Simpson diversity. β–diversity was dominated by nestedness. Climate was associated mainly with activity density and alpha diversity, whereas vegetation showed more recurrent associations with beta diversity. Ground–active beetle assemblages therefore remained regionally distinct despite occurring in the same perennial crop, supporting biodiversity assessment that accounts for dryland regional context. Full article

Carnivorous plants recruit defense-related pathways for prey digestion, yet the cis-regulatory architecture underlying their expression remains poorly characterized. In addition to herbivore and fungal pathogen responses, chitinases play an important role in plant carnivory. We analyzed promoters of glycoside hydrolase family 19 (GH19) class I chitinase genes in the Droseraceae family, which are the most abundant chitinases associated with prey digestion. Promoters of newly identified putative class I chitinases found in Drosera spatulata, Drosera tokaiensis, and Aldrovanda vesiculosa were also examined. Core promoter features, cis-regulatory elements, transcription factor binding site (TFBS) profiles, de novo motifs, and promoter sequence divergence were assessed. Within the sampled promoter set, no single cis-element or transcription factor family-compatible pattern was shared by all carnivorous promoters while being absent from Arabidopsis reference promoter. Instead, Droseraceae promoters showed candidate ATG-relative positional configurations of shared stress-, defense-, and hormone-responsive elements, including a distal MYC/E-box-compatible–proximal W-box pattern, while an ordered DRE–W-box–ERE configuration occurred in six sundew promoters. The TFBS profiling revealed promoter-specific differences in the representation of loci compatible with bHLH-family models, WRKY, MYB, MYB-related, NAC, and HSF models. Together, these analyses identify candidate promoter-specific patterns and provide a foundation for further broader comparative and functional validation. Full article

Marine herbivorous isopods can have negative impacts on cultivated marine macroalgae, in the same way that terrestrial insects can negatively affect plant communities. Color preference of harmful insects has been studied and applied in controlling their populations, but that of isopods has rarely been examined. This study examined the substrate and light color preferences of the marine isopod Cymodoce japonica, a species impacting the cultivation of brown macroalgae in northeastern Japan. The number of isopods positioning themselves on blue-colored substrates was lower than that on red-, orange-, and yellow-colored substrates. There was no difference in the time spent in a dark compartment compared with a compartment illuminated with red light, but the time spent in a compartment illuminated with blue or green light was shorter than in a dark compartment. Moreover, the time spent in compartments irradiated with blue light was shorter compared with compartments irradiated with red light. These results indicate that this species is more sensitive to blue substrates and light than to other colors under the tested conditions. These behavioral characteristics of this species provide important insights for developing methods to suppress the aggregation and herbivory of this species in marine macroalgal farms. Full article

Herbivore-induced plant volatiles (HIPVs) are well recognized for their ability to recruit natural enemies of insect herbivores; however, their function in priming plant anti-herbivore defenses remains poorly elucidated. Here, we demonstrate that volatile exposure to a commercial β-ocimene isomer mixture (hereinafter referred to as β-ocimene) enhances anti-herbivore defense responses in tomato (Solanum lycopersicum) against the polyphagous lepidopteran pest Spodoptera litura (Fabricius). Larval infestation by S. litura significantly upregulated the expression of ten terpene synthase (TPS) genes that govern the biosynthesis of four dominant monoterpene HIPVs: β-ocimene, (-)-α-phellandrene, myrcene, and limonene. Preliminary bioassays revealed that pre-exposure to these four monoterpenes significantly enhances tomato resistance to S. litura larvae, with β-ocimene exhibiting the most pronounced effect. A 24 h pre-exposure to β-ocimene substantially augmented tomato antiherbivore resistance, and this protective response persisted for up to 10 days. Biochemical and molecular analyses revealed that pre-exposure to β-ocimene elevated the endogenous accumulation of jasmonic acid (JA) and jasmonoyl-isoleucine, along with increased transcript levels of the JA biosynthetic genes LOXD and AOS. Consistently, the JA biosynthesis-deficient mutant spr8 failed to exhibit strengthened antiherbivore resistance upon β-ocimene pre-exposure. Collectively, our results demonstrate that β-ocimene pre-exposure enhances tomato antiherbivore resistance via activating JA biosynthesis, highlighting the potential ecological function of HIPVs in priming plant defense against insect pests. Full article

Abamectin trunk injection is used to control pine wilt disease, but field evidence linking injection history to non-target arthropod communities is limited. We compared uninjected plots with plots injected once in March 2024 (ATI1) or March 2022 (ATI3) in a Pinus massoniana plantation in the Qinling–Daba Mountains. Three plots per history were sampled in July, September, and November 2025. Morphological identification and cytochrome c oxidase subunit I metabarcoding characterized soil-associated arthropods and aboveground Hymenoptera; feeding guilds were assigned at the family level. Litter residues and soil properties were measured. Overall Shannon diversity did not differ significantly among histories in either assemblage. Overall composition differed significantly for soil-associated arthropods but not Hymenoptera. Compositional differences occurred among soil detritivores, herbivores, and microbivores and among hymenopteran parasitoids, predators, and pollinators. Hymenopteran herbivore and pollinator diversity was higher in ATI1 and ATI3, respectively, whereas no soil feeding guild showed significant diversity differences. Residues were detected in both injected groups and were higher in ATI1. Redundancy analysis suggested directional associations with residues or soil properties, but these were descriptive rather than evidence of significant correlations. Injection-history associations were taxon- and metric-specific, supporting integrated diversity, composition, and feeding-guild assessments in non-target monitoring and risk evaluation. Full article

Little is known about insect–plant interactions in high alpine environments. We studied the insect herbivore feeding guild in inflorescences of Cirsium funkiae (Asteraceae), an alpine thistle endemic to the southern Rocky Mountains, USA. We asked whether site (open talus above treeline, mid-elevation wet meadow, or lower-elevation forest edge just below treeline) and plant characteristics affect insect abundance, guild composition, and intensity of herbivory. We dissected flower heads collected at season’s end to quantify fly occurrence and measure herbivory damage. Three tephritid flies—Chaetostomella undosa, Paracantha gentilis, and Terellia occidentalis—strongly dominated the herbivore guild. All three species differed in abundance and composition across habitat sites. Chaetostomella dominated in the high, open talus habitat; Terellia peaked in the mid-elevation meadow site; and Paracantha dominated in the lower forest edge site. While Terellia abundance was strongly associated with flower head diameter, abundances of Paracantha and Chaetostomella were only weakly associated with flower head size, suggesting species-specific flower-head selection. Paracantha and Terellia showed elevated co-occurrence at the mid-elevation alpine meadow site, indicating shared distributional preferences likely related to their occurrence on thistles at lower elevations in this region. Unexpectedly, seed damage was extremely high (91.5–98.5%) across all three sites and highest in the characteristic habitat, open high talus slopes. Despite uniformly high seed damage, the low Forest Edge plants had significantly more viable seeds than did the High site plants (8.2% vs. 1.6%), and the difference was associated with differences in guild composition. These findings demonstrate that tephritid flies dominate floral herbivory on the high alpine Cirsium funkiae, that site differences can shape fly feeding guild structure, and that they have a measurable negative impact on plant seed reproductive success in high alpine environments. Full article

Maize, the queen of cereals, is generally affected by several insect pests throughout its lifecycle and by post-harvest pests, which affects yield and grain quality, resulting in heavy reliance on chemical insecticides. Although host-plant resistance is environmentally friendly, its polygenic inheritance, genotype-by-environment interactions, the defence–yield trade-off, and pests’ ability to adapt quickly make it imperative for researchers to understand the genetic architecture in order to initiate insect resistance breeding programs in maize. This review critically summarises the genetic, biochemical, and physiological baseis of insect resistance in maize, including mechanisms of antixenosis, antibiosis, tolerance, structural barriers, benzoxazinoids, protease inhibitors, and herbivore-induced volatiles and jasmonate-mediated signalling. It also assesses the advancement of germplasm screening, conventional and marker-assisted breeding, quantitative trait locus mapping, genome-wide association studies, genomic selection, clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) genome editing, and transgenic Bacillus thuringiensis (Bt) technologies. It seems that for durable resistance to be achieved, it will be necessary to combine complementary defence mechanisms rather than relying on single loci or toxins. Future progress needs to incorporate landrace and wild-relative diversity into high-throughput phenotyping, pangenomics, multi-omics, multi-environment prediction, functional validation, and resistance management. This integrated approach can facilitate the development of higher-yielding, climate-smart, multi-pest-resistant maize and minimize pesticide use and associated environmental impacts. Full article

Plant–animal communication involves diverse forms of information transfer that can mediate ecologically important interactions, including pollination, seed dispersal, herbivory, and plant defense. This review synthesizes current knowledge of the chemical, visual, gustatory, electrical, acoustic, and vibrational information involved in these interactions, with particular emphasis on volatile organic compounds, herbivore-derived elicitors and effectors, multimodal signaling, sensory perception, learning, and evolutionary processes, including coevolution where reciprocal evidence is available. A central distinction is made between detectable traits or cues and functional biological signals, emphasizing the need for evidence linking signal production or modification to receiver detection, behavioral or physiological responses, and ecologically meaningful outcomes. Acoustic and vibrational phenomena are considered critically because their communicative significance remains less firmly established than that of chemical and visual signaling. The review further examines how climate change and other anthropogenic pressures may alter signal production, transmission, perception, and phenological synchrony, thereby reorganizing plant–animal interactions. Genetic manipulation of hormonal, volatile, and specialized-metabolite pathways is also evaluated as a potential tool for modifying plant signaling, together with its possible unintended ecological consequences. By integrating plant physiology, sensory ecology, animal behavior, evolution, and environmental change, this review identifies major evidence gaps and highlights the importance of plant–animal communication for biodiversity conservation, pollination, biological control, and sustainable agriculture. Full article