Search Results (1,762)

Complexes of colchicine, colchiceine, and 10-methylthiocolchicine with Li⁺, Na⁺, and K⁺ cations in the form of chlorides were synthesized and then subjected to spectral analysis, DFT theoretical studies, and molecular modeling. The values for water solubility and lipophilicity were also determined using various platforms; both factors are very important for determining the bioavailability of the tested compounds. These compounds were also tested for their fungicidal, herbicidal, insecticidal, and cytotoxic activities. Preliminary in silico studies showed that colchicine, colchiceine, 10-methylthio-colchicine, and their chloride complexes are inactive against selected fungi, weeds, and insects. Colchicine did not show antifungal properties in biological tests and was only active against Aureobasidium pullulans, as were its chloride complexes. The process of complexing colchiceine with metal cations in chloride salts significantly improved the antifungal potency against the selected species A. pullulans and Chaetomium globosum. The highest efficacy of colchiceine complexes was observed only against A. pullulans (MIC = 130 µg/mL) and Ch. globosum (MIC = 65 μg/mL). In contrast to the antifungal activity results, anticancer studies showed that 10-methylthiocolchicine complexes are more active against the SKOV-3 cell line (~IC50 = 2 nM) than colchicine or colchiceine. Molecular-modeling studies confirmed that lithium-coordinated compounds strongly stabilized the active ligand-tubulin complex, which may contribute to the observed cytotoxic activity. Full article

Intensive horticultural and fruit production in Chile relies on pesticides, raising concerns about compliance with residue limits and the continued availability of highly hazardous pesticides (HHPs). Recent national monitoring data from Chile indicate frequent detections of HHPs in plant-based foods and repeated exceedances of Maximum Residue Limits (MRLs). This study analyzed official datasets from Chile’s Ministry of Agriculture, combining food residue monitoring data from 2015 to 2023 with pesticide sales and import statistics as additional indicators of availability. Active ingredients were standardized to ISO names and CAS numbers and classified for HHP status based on FAO/WHO hazard criteria, with cross-referencing to the Pesticide Action Network (PAN). The results present surveillance indicators focusing on detection rates and MRL exceedance proportions. Between 2015 and 2023, residues were identified in 82.8% of the collected samples. The most frequently detected residues overall included fludioxonil, acetamiprid, pyrimethanil, fenhexamid, and boscalid, indicating a detection profile primarily characterized by fungicides with substantial contributions from insecticides. When restricting to HHPs classified residues, the most frequently detected HHPs included tebuconazole, captan, iprodione, spirodiclofen, chlorantraniliprole, and carbendazim, indicating a detection profile primarily characterized by fungicides, with significant contributions from insecticides. Records of exceedances were concentrated within a limited subset of residues, predominantly acetamiprid and dithiocarbonates, and were most frequently associated with apples, table grapes, cherries, blueberries, pears, and certain vegetables, notably leafy vegetables. The active ingredients classified within HHPs included fludioxonil, fenhexamid, tebuconazole, cyprodinil, and lambda-cyhalothrin. The findings support agronomic decision-making by emphasizing GAP/PHI reinforcement, targeted monitoring, and IPM-based substitution options for activities involving recurrent HHP detection. Full article

The two-spot cotton leafhopper (TSCL), Amrasca biguttula (Hemiptera: Cicadellidae), is an emerging invasive pest in the southeastern United States. Although TSCL has historically been associated with cotton and vegetable crops, recent detections on ornamental hibiscus have raised regulatory concern, including “Stop Sale and Hold” orders and an emergency quarantine in Texas. Despite increasing pressure on hibiscus, no insecticide efficacy data exist for ornamental systems. We evaluated the acute (0–24 h) and residual (24–96 h) toxicity of bifenthrin, flupyradifurone, and tolfenpyrad against adult and immature TSCL using a sequential-cohort leaf-disc bioassay. New insects were introduced at 24 h and 72 h to isolate residue-based mortality from prolonged exposure effects. Bifenthrin caused the highest acute mortality at 24 h, whereas flupyradifurone and tolfenpyrad exhibited slower initial activity but strong residual performance. Immatures were more susceptible than adults across all doses. By 72 h, all three insecticides produced near-complete mortality, with significant treatment and dose effects confirmed by ANOVA and binomial GLM analyses. Dose–response curves showed steep concentration-dependent mortality for bifenthrin and tolfenpyrad and a time-dependent response for flupyradifurone. These results provide the first insecticide efficacy data for TSCL on ornamental hibiscus and offer immediate guidance for nursery producers and regulatory agencies. The findings establish a foundation for whole-plant and greenhouse evaluations to support integrated management and interstate plant-movement compliance. Full article

Cyantraniliprole, a second-generation diamide insecticide, exhibits broad-spectrum efficacy against numerous insect pests due to its selective activation of insect ryanodine receptors (RyRs). This activation triggers uncontrolled calcium release from the sarcoplasmic reticulum, resulting in sustained muscle contraction, paralysis, and ultimately death. Its unique mode of action, which is different from that of organophosphates, carbamates, pyrethroids, and neonicotinoids, helps minimize cross-resistance, making it a valuable component of integrated pest management (IPM). However, continuous field use has led to the development of resistance, primarily mediated by target-site mutations within the RyR transmembrane domain (e.g., G4946E, I4743M, and I4790K) and by enhanced metabolic detoxification via cytochrome P450 monooxygenases, carboxylesterases, and glutathione S-transferases. These mechanisms often confer cross-resistance to other diamide insecticides, thereby complicating resistance management. Moreover, sublethal exposures can disrupt insect growth, development, and reproduction, potentially accelerating resistance evolution. In addition, cyantraniliprole poses ecological risks due to its toxicity to non-target organisms such as aquatic species, including zebrafish and water fleas, pollinators such as honeybees, and soil fauna, as well as the environmental persistence of its major metabolite, J9Z38. This review comprehensively integrated current knowledge on the molecular mechanisms of action, genetic and metabolic bases of resistance, sublethal effects, and ecotoxicological impacts of cyantraniliprole, along with its environmental fate, plant uptake and translocation, and residue dynamics in agricultural systems. Finally, we discuss potential risk-mitigation strategies, including formulation optimization, application-method improvements, and resistance monitoring. Overall, this review aims to provide a comprehensive scientific foundation for the sustainable use, resistance management, and regulatory assessment of this widely used insecticide. Full article

Dillapiol is a naturally occurring methylenedioxyphenyl compound with insecticide-synergizing activity comparable to piperonyl butoxide (PBO). This study identified structurally related molecules with practical potential for managing insecticide-resistant insects. Six new dillapiol analogs, containing ester- or ether-linked side chains, were synthesized and evaluated as pyrethrum synergists against the Colorado potato beetle (CPB) Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). Their activity was assessed through bioassays and by quantifying inhibition of Phase I and II detoxification enzymes in vitro and in vivo. All six compounds displayed higher synergistic activity by ingestion than by topical exposure, and each structural class included at least one compound with a synergism ratio greater than 20. In the resistant CPB strain (RS-CPB), two ester compounds inhibited P450 monooxygenase activity in vitro as effectively as PBO, while dillapiol and one ether analog reduced P450 activity in vivo. Notably, all six analogs reduced glutathione S-transferase (GST) activity; the most active was an ether analog with an in vitro IC₅₀ of 0.23 (±0.04) mM. Dillapiol also significantly reduced GST activity in vivo. These analogs demonstrated PBO-equivalent P450 inhibition combined with unique GST inhibition and show promise as alternative synergists for managing insecticide-resistant insects. Full article

The maize weevil is a major postharvest pest of stored maize, causing substantial quantitative and qualitative grain losses and posing a serious threat to food security. In many regions of the world, particularly in developing countries where maize is a staple crop, maize weevil infestations can account for up to 50% of postharvest maize losses annually. Traditionally, synthetic pesticides have been used to manage maize weevils, but their prolonged application has been associated with environmental contamination, pesticide resistance, and adverse health effects in humans and animals. These challenges have inspired the search for safe, eco-friendly, and bioactive alternatives from natural sources. Citrus plants are among the most widely consumed fruits globally, with their peels and leaves constituting a significant proportion of agricultural waste. These waste products are rich in essential oils, particularly limonene, which has demonstrated potent insecticidal properties against maize weevils. Repurposing citrus waste into biopesticides offers a sustainable strategy for mitigating maize weevil infestations, thereby reducing postharvest maize losses and enhancing food safety and security. This review examines the prospects of citrus limonene in the development of safe and effective maize weevil biopesticides, highlighting its major chemical constituents, biological activities, and mechanisms of action. Full article

Bessera elegans (Asparagaceae) is an endemic Mexican species that is traditionally valued for ornamental purposes and locally reported medicinal uses, yet it remains largely underexplored from phytochemical and biological perspectives. The identification of bioactive secondary metabolites from under-investigated plant species is a key step toward developing plant-derived compounds with potential biotechnological applications. Therefore, in this context, we compile and critically analyze the available information on the botany, phytochemistry, and reported cytotoxic and insecticidal activities of B. elegans. Phytochemical studies, mainly focused on the bulbs, have led to the isolation of steroidal glycosides, homoisoflavonoids, flavonoids, and norlignans. Several of these compounds exhibit cytotoxicity against human cancer cell lines, including leukemia and lung adenocarcinoma models. More recent investigations of flower extracts have revealed additional classes of secondary metabolites and preliminary insecticidal activity, highlighting the species’ chemical diversity. Although the current biological evidence remains limited, the reported cytotoxic and insecticidal effects provide a biochemical basis supporting the relevance of B. elegans as a potential source of plant-derived bioactive compounds. This review highlights existing knowledge gaps and emphasizes the need for further phytochemical and biological studies to support future biotechnological applications of metabolites from underexplored endemic plant species. Full article

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), poses a significant threat to global tomato production. However, environmentally sustainable management strategies for this pest, as well as its mechanisms of insecticide resistance, remain insufficiently understood. Broflanilide, a novel meta-diamide compound, can bind specifically to the transmembrane domain of the RDL subunit, causing prolonged opening of the chloride channel, disruption of neurotransmission, and ultimately insect paralysis and death. This study employed the leaf immersion method to conduct bioassays on the second-instar larvae of T. absoluta to evaluate physiological responses to sublethal concentrations of the novel amide insecticide broflanilide. Subsequently, high-throughput transcriptome sequencing was performed to investigate changes in gene expression and metabolic pathways. Bioassay results determined the larval sublethal concentrations of broflanilide to be 0.136 mg/L (LC₁₀) and 0.210 mg/L (LC₃₀). Sublethal exposure significantly prolonged the larval period, reduced pupal weight, and inhibited fecundity of female adults. Transcriptomic and qPCR analyses revealed that, compared with the control (CK), expression of the vitellogenin gene Vg decreased by 15.99% and 30.27% under LC₁₀ and LC₃₀ treatments, respectively, while its receptor gene VgR decreased by 11.56% and 24.49%. Similarly, expression of chitin synthase genes chs1 and chs2 declined by 13.56% and 30.17% (chs1), and 7.85% and 19.45% (chs2), respectively. Gene expression analysis elucidated how sublethal insecticides treatment impact larval development and fecundity. Furthermore, the study revealed upregulation of cytochrome P450-mediated detoxification pathways and Toll/Imd immune signaling pathways under broflanilide stress, indicating activation of a coordinated defense response in T. absoluta. Sublethal broflanilide exposure modulated larval gene expression to balance growth, development, and stress adaptation. Such exposure exerts selective pressure on susceptible populations, potentially driving adaptive shifts in detoxification metabolism and contributing to the development of field resistance. These findings advance our understanding of the sublethal effects of novel insecticides and provide valuable insights for insecticide deployment strategies and resistance management. Full article

Background: The control of fleas and ticks in companion animals is a persistent challenge with animal welfare and public health implications. The increasing resistance to antiparasitic treatments, coupled with concerns over the environmental impact and non-target effects of synthetic acaricides, has driven interest in sustainable alternatives. Essential oils (EOs) have emerged as potential candidates due to their complex chemistry and modes of action. Methods: This review critically analyzes the scientific literature on essential oils for ectoparasite control in companion animals. Specifically, it examines their chemical composition, multi-target mechanisms of action, laboratory and field efficacy, role in resistance mitigation, and integration into IPM strategies. Results: Several EOs, particularly those rich in phenolic compounds (thymol, carvacrol, eugenol, and cinnamaldehyde), demonstrate promising in vitro insecticidal and acaricidal activity. Their multi-target mechanisms, affecting neuronal, respiratory, and cuticular functions, not only provide efficacy but also represent a significant barrier to rapid resistance development. However, their translation to reliable field performance is hampered by high volatility, formulation instability, and innate variability. Conclusions: EOs represent a valuable source of bioactive compounds for reducing reliance on conventional acaricides and can play a key role within IPM strategies. To realize their full potential in mitigating resistance, focused advancements are needed in standardized testing, formulation science to enhance stability and residual activity, and rigorous field studies to confirm safety and efficacy. Full article

Haiti is a Caribbean country of about 11 million people with a high burden of mosquito-transmitted disease and limited vector control, thereby making effective operational mosquito control of high importance. Previous studies have examined vector-borne disease burden and insecticide resistance markers in Haitian Aedes and Anopheles mosquitoes, but not Culex species. In this study, we examined collections of Culex quinquefasciatus from 12 locations in northern and southern Haiti for the presence of markers of insecticide resistance (using a variety of target-site mutations and biochemical assays) and pathogens (using a deep-sequencing microbiome workflow). The metagenomic analysis identified Wolbachia, Rhabdoviridae, and Plasmodium infections in all sample pools at relatively high levels, along with less frequent detections of other potential pathogens. Insecticide resistance marker examination identified variable frequencies of knockdown resistance and acetylcholinesterase resistance mutations, as well as variation in resistance-associated enzymatic activities in these populations. These findings indicate that insecticide resistance to pyrethroid and organophosphate insecticides is likely. Although there was variation among Culex mosquito populations and no clear activity pattern, enzymatic activity was significantly higher at the southern sites than at the northern sites. Similar findings in Cx. quinquefasciatus populations in other locations in the Americas strongly suggest that vector control with pyrethroid and organophosphate adulticides may be of limited efficacy. Full article

As the main active component of Zanthoxylum bungeanum, its volatile oil (ZEO) exhibits diverse pharmacological activities, including insecticidal, antibacterial, anti-inflammatory, and anti-tumor effects. These properties support its traditional functions, such as “expelling worms” and “warming the Middle Jiao to alleviate pain and relieve itching.” However, modern research mainly validates individual components or effects, leaving notable gaps in understanding this complex system. This review integrates research on ZEO, summarizing its composition, influencing factors, and mechanisms of action. By framing the “composition–activity–mechanism–application” continuum, this review analyzes the basis for the holistic, multi-component, multi-target therapeutic model of traditional Chinese medicine (TCM). It clarifies the core TCM principles of pharmacological symbiosis and synergy through formula compatibility. These insights form a theoretical basis for further development and wider application of ZEO in fields such as medicine, food, and daily chemical products. Full article

Essential oils (EOs) from combined plant materials offer a promising alternative to conventional extraction by enhancing chemical diversity and bioactivity. This study evaluated the chemical composition and insecticidal properties of individual and combined plant EOs from Cymbopogon citratus, Eucalyptus camaldulensis, Eucalyptus lehmannii, Salvia rosmarinus and Thymus vulgaris were evaluated against aphids. Binary and ternary combinations were prepared in equal proportions prior to hydrodistillation. GC-MS analysis revealed significant compositional shifts in EOs from combined plant materials. Major compounds in individual oils included citral (53.11%) and neral (29.14%) in C. citratus, thymol (70.84%) in T. vulgaris, and eucalyptol as the predominant compound in E. camaldulensis (66.51%), E. lehmannii (56.99%) and S. rosmarinus (46.56%), respectively. In the combined oils, the relative abundance of these constituents was altered, and in some cases new constituents were introduced. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) revealed that combined plant EOs clustered near their parental oils, indicating compositional inheritance. Contact toxicity assay against Aphis fabae demonstrated enhanced efficacy of the combined oils, with reduced LC₅₀ values (1.39 µL mL⁻¹ for E. camaldulensis + T. vulgaris) and synergistic interactions, indicated by a co-toxicity coefficient (CTC) of 221.58 and elevated synergistic factors. Pearson correlation analysis and Partial Least Squares (PLS) regression jointly identified Acorenone B and thymol as negatively, and caryophyllene as positively correlated compounds, all with relatively high contribution to insecticidal activity, ranking highest with a Variable Importance in Projection (VIP) scores > 1.0. While PLS model had modest predictive power, the integration of these statistical approaches supports the insecticidal potential of combined plant-derived EOS in laboratory bioassays and indicates their relevance to sustainable crop protection. Full article

New insecticides for indoor residual spraying (IRS) are being developed to manage resistance. Chlorfenapyr (Sylando^® 240SC), a pro-insecticide, is metabolized by active mosquitoes into the toxic metabolite tralopyril. This mode of action requires adapted “free flying” bioassays (because chlorfenapyr is converted to its toxic metabolite tralopyril when mosquitoes are metabolically active). A miniature-experimental hut (MEH) assay was developed within the Ifakara Ambient Chamber Test (I-ACT) with a rabbit as a host to measure residual efficacy under controlled conditions. Sylando^® 240SC was compared with SumiShield^® 50WG (clothianidin) for 12-month residual efficacy against malaria and arbovirus vectors. Residual activity was assessed on mud, wood and concrete with two huts per substrate treated with Sylando^® 240SC, one with SumiShield^® 50WG, and one with untreated control. Five replicates of 20 mosquitoes per strain (malaria vectors: pyrethroid-susceptible Anopheles gambiae and -resistant An. arabiensis and An. funestus; culicines Aedes aegypti and Culex quinquefasciatus) were exposed overnight at one-week post spraying and monthly thereafter. Multivariable mixed-effect logistic regression with binomial errors and log link function assessed non-inferiority with a 7% margin on mosquito mortality as the primary outcome for malaria vectors. Both products induced delayed mortality, with higher effects on malaria vectors than culicines. Across all substrates and malaria species combined over the full 12 months of observation, Sylando^® 240SC was non-inferior to SumiShield^® 50WG on mortality measured at 72 h (76% vs. 67%, OR = 0.86, 95% CI: 0.77–0.97) and 168 h (89% vs. 82%, OR = 0.74, 95% CI: 0.63–0.87). Sylando^® 240SC performed comparably to SumiShield^® 50WG, supporting its use as an IRS additional option. The new I-ACT mini-experimental-hut assay provides a practical tool for evaluating pro-insecticides. The importance of free-flight evaluation methods for pro-insecticides is discussed. Full article

Clothianidin (CLO) is a widely used neonicotinoid insecticide in agricultural systems and may pose risks to non-target aquatic organisms, including amphibians. Here, we evaluated acute and sublethal effects of CLO on Fejervarya cancrivora tadpoles, an important predator of insect pests in rice paddy ecosystems. Acute toxicity tests (96 h) yielded an LC₅₀ of 50.41 mg a.i./L (with LC₁₀, LC₂₅ and LC₃₀ values of 15.35, 31.96 and 36.07 mg a.i./L, respectively). Sublethal exposure at these concentrations significantly reduced body weight, whole-body length, and hindlimb length during metamorphosis. CLO also altered thyroid hormone regulation, with T4 showing a dose-dependent increase, while T3 was elevated relative to controls but showed comparatively limited additional sensitivity to concentration and exposure duration. Locomotor activity was impaired under sublethal CLO exposure, reflected by reduced swimming distance and speed. In addition, frogs that developed from CLO-exposed tadpoles exhibited decreased feeding efficiency on brown planthoppers (Nilaparvata lugens) across developmental stages 46–48. Together, these findings demonstrate that CLO can affect amphibian development, endocrine regulation, and behavior at sublethal levels, highlighting the need to incorporate sublethal endpoints into ecological risk assessment and to promote pest management strategies that reduce impacts on biodiversity and ecosystem services. Full article

Abamectin is a widely used insecticide for controlling various pests, including the codling moth (Cydia pomonella). However, with the increasing emphasis on green agriculture, its potential risks to beneficial insects such as honeybees have attracted growing concern. To tackle these challenges, we established a novel nanopesticide delivery system. Specifically, a nanopesticide (Abm@TPP/CMCS) based on carboxymethyl chitosan (CMCS) cross-linked with sodium tripolyphosphate (TPP) was constructed to improve insecticidal efficacy while lowering environmental risks. The prepared nanoparticles presented a spherical and monodisperse morphology with an average size of 85.12 nm (at 0.3 mg/mL) and an encapsulation efficiency of 23.1%. Laboratory bioassays indicated that the nanopesticide exhibited significantly higher toxicity against C. pomonella (LC₅₀ = 0.371 μg/mL) than technical-grade abamectin (LC₅₀ = 0.580 μg/mL), with a corresponding toxicity ratio of 1.563. Its excellent control effect was further confirmed in field trials, with a control efficacy of 85.71% at 10 days after application, which was markedly higher than that of conventional formulations. Notably, nanoencapsulation significantly reduced environmental toxicity: the LC₅₀ value for Apis cerana increased from 0.312 μg/mL (highly toxic) for technical abamectin to 4.162 μg/mL (moderately toxic), and from 684.28 μg/mL to 1484.30 μg/mL for Eisenia fetida. In addition, the nanopesticide showed favorable biosafety toward wheat, maize, and beans, and even promoted root growth in maize. In summary, Abm@TPP/CMCS enhances insecticidal activity against C. pomonella, reduces toxicity to non-target organisms, and enables controlled release, which provides a promising strategy for eco-friendly pest management. Full article