Search Results (613)

The American grapevine leafhopper (Scaphoideus titanus) is a major threat to grapevine production, as it is the primary vector of the flavescence dorée phytoplasma. Its ongoing spread poses a serious risk to several viticultural regions, including Italy. This study evaluates the efficacy of a plant-derived formulation composed of extracts of Salvia guaranitica, Capsicum annuum ‘Cayenne’, and olive oil (Form) against S. titanus, through laboratory bioassays and field trials conducted in 2024 and 2025. In laboratory assays, Form applied at 0.5% caused 84.0% mortality in S. titanus adults, while at 2% mortality reached 94.3%. In field trials, prior to treatment (1 August 2024), the average number of adults captured was 3.9 per trap in both vineyard blocks. Four days after treatment (12 August 2024), captures decreased significantly to two per trap in the treated vineyard, whereas they increased to 8.2 per trap in the untreated block. Eight days after treatment (16 August 2024), captures in the treated vineyard remained low (2.4 per trap), while the untreated vineyard maintained high levels (eight per trap). Nymph monitoring showed a similar trend. Before treatment, the incidence of S. titanus was 44.0% and 46.0% in untreated and Form-treated plants, respectively. After treatment (8 June 2025), the percentage of leaves hosting nymphs rose to 84.0% in the untreated vineyard but remained stable at 44.0% in the Form-treated area. Overall, these results demonstrate that Form exerts a measurable toxic effect on S. titanus under both laboratory and field conditions. The findings suggest that a plant-derived formulation such as Form represents a promising alternative to chemical insecticides for controlling the main vector of flavescence dorée and could be integrated into sustainable management strategies. Full article

Insecticide-treated nets (ITNs), particularly long-lasting insecticide-treated nets (LLINs), are important for malaria control; however, the rise of insecticide resistance, behavioral adaptations in mosquito vectors, and diminishing net durability may affect their efficacy. The objective of this systematic literature review and meta-analysis to synthesize recent epidemiological evidence (2021–2025) on the correlation between ITN/LLIN use and Plasmodium falciparum infection prevalence and to explore sources of heterogeneity across populations, settings, and type of nets. Searches across PubMed, Scopus, and Web of Science yielded 3151 records, of which 10 met the inclusion criteria. Two separate meta-analyses were performed for crude and adjusted effect estimates using random-effects models. The crude-effects meta-analysis included six studies comprising 7466 participants and yielded a pooled odds ratio of 0.67 (95% CI: 0.42–1.07; p = 0.078), indicating no statistically significant association between ITN/LLIN use and P. falciparum infection. Significant heterogeneity was observed (I² = 79.8%), which was partially explained by population type (59.3%) and study design (36.1%). Subgroup analysis revealed comparable infection prevalence–based associations for ITNs (OR = 0.72) and LLINs (OR = 0.59) use. Assessment of publication bias indicated slight asymmetry; however, the trim-and-fill adjustment did not significantly change the conclusions. The adjusted-effects meta-analysis, comprising nine studies, yielded a non-significant pooled effect (aOR = 0.88; 95% CI: 0.42–1.86; p = 0.71) with substantial heterogeneity (I² = 88.7%). Meta-regression analyses indicated that effect estimates varied by population group and country, with statistically significant modifiers observed for children under five years (p = 0.0098) and for studies conducted in Uganda (p = 0.0378). The type of net contributed to variation between studies, with insecticide-treated nets (ITNs) exhibiting lower pooled odds than long-lasting insecticide-treated nets (LLINs) (p = 0.0415). Overall, this meta-analysis found no conclusive evidence of a statistically significant association between ITN/LLIN use and P. falciparum infection in contemporary epidemiological studies. The substantial heterogeneity across settings underscores the context-dependent nature of observed associations and highlights the need for integrated vector-control strategies and continued evaluation of net technologies under conditions of increasing resistance. Full article

Chirality has emerged as a critical determinant in the design, efficacy, and environmental behavior of modern insecticides. While a significant proportion of agrochemicals are inherently chiral, most are still commercialized as racemic mixtures, despite well-documented differences in biological activity, toxicity, and degradation pathways between enantiomers. In this review, we provide a comprehensive and critical analysis of advances in the stereoselective synthesis and resolution of chiral insecticides, with particular emphasis on neonicotinoids, pyrethroids, and oxadiazines, including indoxacarb. A systematic survey of the literature (1985–2025), including peer-reviewed articles and patents, reveals that multiple strategies have been developed to access enantiomerically enriched compounds, including asymmetric organocatalysis, transition-metal catalysis, chiral-pool approaches, biocatalytic transformations, and chromatographic resolution techniques. Among these, recent developments in photoredox catalysis, recyclable metal complexes, and enzyme-mediated processes have significantly improved enantioselectivity and scalability, bridging the gap between academic methodologies and industrial applications. Despite these advances, challenges remain in achieving cost-effective, sustainable, and universally applicable asymmetric processes. Importantly, the relationship between stereochemistry and biological performance underscores the need for integrating synthetic chemistry with toxicological and environmental studies. Future directions point toward the incorporation of green chemistry principles, continuous-flow processes, and computational tools, including machine learning and molecular modeling, to accelerate the rational design of enantiopure agrochemicals. This review highlights both the progress achieved and the critical gaps that must be addressed to realize the potential of stereoselective insecticide development fully. Full article

The ban on neonicotinoid seed treatments in the EU has created major challenges for maize and sugar beet production, as these chemicals have been highly effective in controlling early-season pests, including wireworms (Agriotes spp.), sugar beet weevil (Asproparthenis punctiventris Germar) (SBW) and sugar beet flea beetles (Chaetocnema tibialis Illiger) (SBFB). However, adequate alternatives have not yet been introduced. The aim of this research was to get insights on the biological activity of insecticides with distinct modes of action and comparatively more favorable ecotoxicological profiles than neonicotinoids, chlorantraniliprole, spinosad, and azadirachtin, applied as seed treatments in maize and sugar beet against wireworms in maize and against SBW and SBFB in sugar beet. In laboratory trials, each insecticide was tested as a seed treatment at three different doses. Thiamethoxam was included as the standard treatment (positive control). Among the tested insecticides, spinosad seed treatment showed the highest efficacy against wireworms and was superior to both the standard insecticide and chlorantraniliprole, while azadirachtin showed no effect. None of the tested insecticides provide satisfactory control of SBW. In contrast, SBFB responded to all three insecticide treatments, with efficacy comparable to, or even better than, the standard insecticide. These results suggest that chlorantraniliprole, azadirachtin, and spinosad may all represent promising candidates for sugar beet seed treatment to protect young plants against SBFB. Future research should focus on developing seed treatment formulations and field and semi-field trials as well as evaluating combinations of active ingredients and their suitability for integration into IPM programs. These findings provide a basis for further development of seed treatment strategies aimed at reducing dependence on neonicotinoids in maize and sugar beet production. Full article

Whiteflies, including Aleyrodes proletella, are major agricultural pests which cause significant yield losses through direct feeding damage and virus transmission. The entomopathogenic fungus Beauveria bassiana is a promising alternative to synthetic insecticides. However, its field performance is often constrained by environmental sensitivity and limited formulation stability. In this study, biopolymer-based suspensions incorporating B. bassiana strain 730 were developed using chitooligosaccharide (COS) and 2-hydroxyethyl cellulose (HEC) as biodegradable carriers. Rheological analysis showed increased viscosity upon fungal incorporation (from 75 to 226 cP for COS and from 250 to 354 cP for HEC), indicating effective interaction between the polymer matrices and fungal conidia. Scanning electron microscopy confirmed uniform dispersion and physical entrapment of fungal structures, while microbiological assays demonstrated preserved viability and sporulation capacity. Bioassays against eggs and nymphs of A. proletella revealed a clear time-dependent response, with limited efficacy after 24 h but substantial increases by day 3. The unformulated fungal suspension achieved 93.0% efficacy, while COS/B. bassiana and HEC/B. bassiana formulations reached 84.6% and 76.1%, respectively, comparable to the commercial product Naturalis^® (87.2%). Polymer solutions applied alone exhibited significantly lower activity. These results demonstrate that biopolymer-based formulations, particularly COS-based systems, preserve fungal virulence and represent promising biodegradable delivery platforms for sustainable whitefly management. Full article

Spodoptera litura is a highly destructive agricultural pest with increasing reliance on chemical insecticides. We aimed to develop nanotechnology-enabled strategies that enhance insecticide efficacy against S. litura and reduce chemical inputs. To this end, SlChitinase5 was identified and characterized as a potential RNAi target. This gene contains conserved domains typical of lepidopteran chitinases and is highly expressed during key developmental stages, including larval molting and the prepupal phase. RNAi-mediated suppression of SlChitinase5 through larval injection of double-stranded RNA (dsSlChitinase5) significantly reduced body weight, increased mortality, and disrupted molting. When RNAi-treated larvae were exposed to sublethal concentrations of emamectin benzoate (EB) or an emamectin benzoate–tebufenozide mixture (EBT), larval mortality reached 96.7% on day 5. To evaluate an alternative formulation and exposure approach, dsSlChitinase5 was incorporated into chitosan nanoparticles (CS) and applied topically. This treatment induced SlChitinase5 knockdown and, in combination with sublethal EB or EBT, resulted in complete larval mortality within five days under the conditions tested. These findings validate SlChitinase5 as a molecular target and suggest that CS-dsSlChitinase5 nanocarriers have the potential to enhance insecticide performance, which may support integrated pest management and future efforts toward reduced-input crop protection strategies. Full article

Low Bt toxin concentration in seeds results in low insecticidal efficacy in transgenic Bt cotton. In order to improve the insecticidal efficacy of seeds, two treatments with different amino acid combinations (5 amino acids comprising aspartic acid, glutamic acid, proline, methionine, and arginine; and 21 amino acids) were applied to two Bt cotton cultivars at peak boll stages in 2021 and 2022. The results showed that the amino acid treatments enhanced the seeds’ Bt toxin concentration by 13.5–34.2% compared with the untreated control in a two-year study. However, the difference for the Bt toxin was not significant between the two amino acid treatments. In the seeds, Bt toxin levels correlated positively with amino acid and soluble protein contents, as well as Glutamic-Pyruvic Transaminase (GPT) and Glutamate Oxaloacetate Transaminase (GOT) activities. Conversely, negative correlations were observed between the Bt toxin and the activities of protease and peptidase. Compared with the control, hazard boll rates were also reduced following application of the two amino acid combinations, while no difference was observed between the two amino acid treatments. Because the two treatments performed similarly, these results suggest that applying a simpler combination of five amino acids is an effective and efficient strategy for enhancing the insecticidal efficacy of cotton seeds. Full article

Space spraying and mass trapping represent distinct adult mosquito control strategies with fundamentally different population-level consequences. We developed a density-regulated population model incorporating either pulsed mortality from spraying (efficacy α = 0.2–0.6 per application) or continuous proportional removal through trapping. Parameters were derived from empirical island datasets. Spraying produced rapid but transient reductions and required high-frequency re-application (weekly to daily) to approach structural suppression when α ≤ 0.4. Consistent with model predictions, analysis of Maldivian resort practices indicated that daily spraying is common in operational settings. In contrast, trapping shifted long-term equilibrium density and induced population collapse above a model-estimated threshold density that, under the baseline parameterization used here, corresponded to approximately 8–10 traps per hectare in geographically bounded island systems. Sensitivity analyses demonstrated that qualitative outcomes were robust across plausible parameter ranges. Economic comparison indicated that spraying frequencies required to match threshold trapping substantially increased cumulative cost. In small island settings with negligible immigration, threshold-based mass trapping provides a structurally stable pathway toward sustained suppression, whereas spraying remains primarily a rapid-response tool with limited durability under moderate-efficacy conditions. When potential ecological externalities and human health considerations associated with repeated insecticide use are considered, trapping may offer additional advantages beyond purely economic comparisons. Full article

Spotted-wing Drosophila (Drosophila suzukii), an economically important invasive but widely distributed pest, has developed resistance to multiple insecticide classes, threatening its management in commercial soft fruit production. This study evaluated the synergism of piperonyl butoxide (PBO) with zeta-cypermethrin in two field-collected resistant California populations and a susceptible population with bioassays. Female flies from the two resistant populations exhibited 55-fold and 25-fold resistance, respectively, compared to the susceptible population. PBO co-application significantly enhanced insecticide efficacy in both resistant populations, with synergism ratios of 6.51 and 4.06. However, complete susceptibility at label rates of the insecticide was not restored, indicating that other resistance mechanisms may also be present in these populations. PBO–pyrethroid combinations show promise for improving field efficacy against resistant populations, though they should be integrated with insecticide rotation and other integrated pest management tactics for sustainable resistance management. Full article

Background/Objectives: As a traditional Chinese medicinal herb, Cnidii Fructus is widely used in clinical practice. Its volatile organic compounds (VOCs) are closely related to its antipruritic effect and insecticidal properties. Due to the susceptibility of this medicinal herb to mold contamination, adopting appropriate sterilization measures is of great significance for its storage. ⁶⁰Co irradiation is widely used for this purpose due to its various advantages. Methods: This study employed Gas Chromatography–Ion Mobility Spectrometry (GC-IMS) combined with multivariate statistical analysis to systematically investigate the influence of different ⁶⁰Co irradiation doses (0, 3, 6, 9 kGy) on the VOCs of Cnidii Fructus and associated metabolic regulatory mechanisms. Results: A total of 115 VOCs were tentatively identified. Statistical analysis revealed dose-dependent effects: 3 kGy irradiation caused the least compositional perturbation, best preserving original chemical characteristics; 6 kGy induced more pronounced compositional changes; and 9 kGy triggered substantial chemical composition reconstruction. Differential metabolite enrichment analysis indicated that medium and high doses of irradiation primarily perturbed central carbon metabolic pathways, including pyruvate metabolism, glycolysis/gluconeogenesis, and glyoxylate and dicarboxylate metabolism. Key differential components were tentatively identified (e.g., α-Thujone, α-Pinene, β-Pinene) that possess pharmacological activities closely associated with the traditional efficacy of Cnidii Fructus. Conclusions: When the irradiation dose is 3 kGy, the VOCs profile of Cnidii Fructus is most similar to that of the non-irradiated control group, suggesting that its compositional profile may be closer to that of traditional high-quality medicinal materials. Meanwhile, the differential metabolites and core metabolic pathways identified in this study can provide a chemical reference for the quality control of irradiated Cnidii Fructus. The findings provide a theoretical basis and technical support for the rational application of ⁶⁰Co irradiation sterilization in the processing of Chinese medicinal materials and their powders. Full article

A series of hexadecylpiperidinium surfactants containing alkyl (PMe-16, PEt-16, PBu-16), benzyl (Benz-16, 1-Benz-3-HP-16, 1-Benz-4-HP-16), and hydroxyl (3-HPMe-16, 4-HPMe-16) substituents in the ring were tested with the nematode Caenorhabditis elegans to investigate the relationship between nematocidal activity and the structural features of surfactants. It was found that increasing the hydrophobicity of the substituent in the surfactant head group reduced the nematocidal activity in the order PMe-16 > PEt-16 > PBu-16 > Benz-16. The lead compound, PMe-16, showed significantly higher activity than the commercial insecticide carbofuran, and was able to induce nearly complete nematode mortality within 24 h at a concentration of 50 μg·mL⁻¹, as well as suppress culture development at concentrations of 25–100 μg·mL⁻¹. All tested piperidinium surfactants inhibited nematode population development at 100 μg·mL⁻¹, while PMe-16 remained effective at concentrations as low as 25 μg·mL⁻¹. The membranotropic properties of the surfactants were evaluated using a turbidimetric method with dipalmitoylphosphatidylcholine (DPPC)-based liposomes as a model of biomembranes. Dynamic light scattering measurements were performed in parallel to assess changes in liposome size and zeta potential as a function of surfactant content, as well as to determine the critical concentration required to induce lipid bilayer destabilization. These results provide indirect evidence of surfactant–membrane interactions. The combinations of piperidinium surfactants and carbofuran showed pronounced synergistic effects, reducing the insecticide dose while maintaining efficacy. Synergy was evaluated using the Bliss independence model and the Highest Single Agent model. The addition of the most active surfactants (PMe-16 and 4-HPMe-16) at 6.25 μg·mL⁻¹ enabled an approximately twofold reduction in the carbofuran dose while maintaining full nematocidal activity. Full article

In the framework of integrated pest management, plant-based insecticides represent a promising tool for the control of insect pests. Indeed, N-alkylamides extracted from Acmella oleracea (L.) RK Jansen (Asteraceae) have been recently studied for their insecticidal properties. The encapsulation of these substances into stable formulations, like nanoemulsions (NEs), could boost their efficacy and stability. Herein, a N-alkylamide-enriched fraction (AEF) encapsulated into a stable NE was tested against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), a key tomato pest, able to develop resistance towards chemical insecticides. Acmella oleracea was reported to be effective against many target species, but this is the first time that this extract was tested against T. absoluta in terms of toxicity against eggs, ingestion toxicity on larvae and repellence on adults. The AEF, containing 42.8% of spilanthol, was prepared by combining two eco-friendly techniques, namely supercritical CO₂ extraction and wiped-film short path molecular distillation, and then encapsulated into a stable NE. Preliminary tests on the phytotoxicity of the AEF-NEs at 0.25 and 0.5% (w/w) a.i., compared with a control NE solution (i.e., the AEF-free NE) and a negative control (distilled water), showed a negative effect on tomato plants at the highest concentration. On this basis, three concentrations (0.06, 0.125, and 0.25% a.i.) were evaluated against eggs (topical toxicity), larvae of 2nd instar (ingestion and topical toxicity), and adults (ovideterrence) of T. absoluta. The results showed that all adopted AEF-NE concentrations caused a significant inhibition in egg hatching (>20%). The larval survival, at the end of the evaluation (72 h), in ingestion toxicity tests were significantly different in the AEF-NEs at 0.06, 0.12, and 0.25% (56.7, 33.3 and 26.7%, respectively) compared with control NE and distilled water (100% both). Similar results were obtained in the adult emergence in ingestion toxicity comparing AEF-NEs at 0.06, 0.12, and 0.25% (64.7, 50.0 and 75.0%, respectively) with control NE and distilled water (100% both). Finally, a significant ovideterrent effect was shown by the concentrations 0.125 and 0.25% of the AEF-NEs (% of egg laid: 7.5 and 27.4% respectively), compared with distilled water. Overall, the AEF-NE tested showed promising and encouraging effectiveness as ovicidal and larvicidal against T. absoluta. This supports its potential use as an effective alternative to synthetic products for the control of this important pest. Full article

Background/Objectives: Malaria remains a major global health burden, particularly in sub-Saharan Africa, where the recent invasion and urban expansion of Anopheles stephensi are increasing transmission risk in densely populated areas. Conventional vector control strategies, including widespread insecticide application, are progressively losing efficacy due to the rapid spread of resistance. These limitations have accelerated the development of genetic control approaches aimed at either suppressing vector populations or replacing them with genetically modified mosquitoes incapable of transmitting pathogens, with the shared objective of reducing disease transmission. For population suppression strategies, an essential component is a conditional regulatory system that enables precise control of toxic or otherwise deleterious effector proteins. The most widely used platform, the tetracycline-dependent (Tet) system, modulates gene expression in response to tetracycline. However, this system can exhibit leaky expression and variable regulation, which may compromise its reliability and limit its application in certain contexts. The dihydrofolate reductase (DHFR) destabilization domain (DD) system, developed in Drosophila, offers an alternative strategy for post-translational control of protein stability. In this system, proteins fused to a destabilization domain are rapidly degraded unless stabilized by the small molecule trimethoprim (TMP), enabling tight and reversible control. In Drosophila and prior reports, this system has been associated with relatively low fitness costs, although such effects have not been systematically evaluated in mosquitoes. Before adapting this system for mosquito genetic control, it is therefore essential to assess the impact of TMP exposure on key life-history traits. Methods: Here, we assessed the effects of varying TMP concentrations on mosquito development, survival, and reproductive output. Results: Our results demonstrate that low concentrations of TMP exposure had no detectable effects on immature development, adult survival, or reproductive output under the conditions tested, supporting the implementation of the DHFR-DD system in mosquitoes. Importantly, these effects were dose-dependent, with moderate to high TMP concentrations producing measurable impacts on mosquito fitness. Conclusions: These findings provide a foundational step toward the development of more precise and reliable conditional expression systems for genetic vector control, advancing innovative strategies to mitigate malaria transmission in high-risk regions. Full article

Introduction: Placental malaria increases the risk of adverse birth outcomes. Current preventive measures are undermined by poor coverage, growing resistance to chemo-preventive and therapeutic drugs, and vector eliminating insecticides. Candidate placental malaria (PM) vaccines (PAMVAC and PRIMVAC) have shown safety and immunogenicity in Phase I trials, but empirical evidence on their potential population-level value is lacking. This study modelled the expected cost-effectiveness of a PM vaccine administered before pregnancy. Methods: A decision-analytic model compared two strategies from the provider’s perspective: vaccinating women of childbearing age versus no vaccination. The model incorporated gravidity-specific risks of PM, neonatal mortality and the malaria attributable fractions from the literature. Since the efficacy of a PM vaccine for malaria prevention is unknown, we assumed a 40% efficacy and varied this estimate widely in sensitivity analyses. Primary outcomes were incremental cost-effectiveness ratios (ICERs) per perinatal disability adjusted life years (DALYs) averted. Baseline, best-case, and worst-case scenarios were analysed. One-way and probabilistic sensitivity analyses were used to assess parameter uncertainty. Cost-effectiveness was defined as an ICER below half of sub- Saharan Africa’s 2025 GDP per capita ($1556). Results: The vaccine was most cost-effective among primigravidae. Under baseline assumptions (40% efficacy; 30% uptake; $5 dose price), the ICER was $321 per perinatal DALY averted for primigravidae versus $4444 for multigravidae. Best-case assumptions further improved cost-effectiveness ($225 vs. $3148). Sensitivity analyses showed robust cost-effectiveness for primigravidae across all plausible parameter ranges, while ICERs in multigravidae were highly sensitive to programme costs and vaccine efficacy. Cost-effectiveness acceptability curves demonstrated that vaccination becomes favourable for primigravidae at relatively low willingness-to-pay thresholds. Conclusions: A placental malaria vaccine delivered before pregnancy has high potential to be cost-effective in endemic areas when targeted to protect primigravidae. These findings support prioritised deployment strategies and highlight the value of early economic modelling to inform vaccine development and policy planning. Full article

The increasing demand for sustainable pest management has positioned essential oils (EOs) as viable bio-based alternatives to synthetic pesticides. This study investigates the insecticidal potential of Haplopappus foliosus EO, a Chilean endemic medicinal plant, against Drosophila melanogaster as a key toxicological model for fruit fly control. Chemical characterization identified 56 compounds, with 4-terpineol (27.27%) and α-bisabolol (10.40%) as the primary constituents, marking the first report of α-bisabolol in this species. To enhance bioavailability and overcome EO volatility, a nanoemulsion was developed, achieving an exceptionally small and stable particle size of 2.10 nm that remained consistent for over 90 days. Nanoencapsulation significantly optimized the EO’s efficacy, reducing the median lethal concentration (LC₅₀) from 120.26 µg/mL to a potent 54.57 µg/mL. While in vitro assays showed the free oil as a more potent acetylcholinesterase (AChE) inhibitor, molecular docking confirmed the high affinity of 4-terpineol and α-bisabolol for the enzyme’s active site, elucidating the neurotoxic mechanism at a molecular level. In silico analysis predicted a favorable human safety profile within GHS classes 4 and 5. Overall, this stable nanoformulation represents a sustainable biotechnological strategy for agricultural pest management, leveraging the synergistic effects and enhanced delivery of natural products. Full article