Search Results (242)

In sub-Saharan Africa, intensive pesticide use in irrigated agriculture is threatening the quality of soil, water bodies and ecosystem services, yet integrated risk assessments remain limited. This study evaluated the environmental implications and risks of pesticide residues in soils (0–20 cm; n = 15) and irrigation water (n = 15) from off-season irrigation area of the Goulbi Maradi Valley, Niger. Twelve commonly used pesticides in Djiratawa, Maradi 3 and Tibiri, were quantified by High-Performance Liquid Chromatography with Variable Wavelength Detector (HPLC-VWD), revealing Tibiri as a contamination hotspot, where the total pesticide residues in soil and irrigation water reached 6.4 and 19.7 times the respective European Union soil and drinking water benchmarks, dominated by Cypermethrin, Emamectin benzoate and Chlorpyrifos ethyl in soils, and Emamectin benzoate and Dichlorvos in water. Multivariate analysis showed that soil particle size, particularly higher clay content, controlled the retention of strongly sorbing compounds, while pH and salinity governed the occurrence of more soluble residues in irrigation water. While non-carcinogenic risks for Adults and Children via soil and water exposure were acceptable (Hazard Quotient and Hazard Index < 1), ecological risks were unacceptable, with Folsomia candida and Daphnia magna the most affected organisms, driven by Emamectin benzoate (Toxicity Exposure Ratio < 2). Priority actions include phasing out Dichlorvos and Paraquat dichloride, tightening controls on Emamectin benzoate and expanding food-chain monitoring, particularly in vegetables and fish, to support multi-trophic risk assessment and safer irrigation management. 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

Antheraea pernyi larvae growing in the wild suffer damage from the drift diffusion of insecticides used in surrounding farmland. In this study, we assessed the toxicity of beta-cypermethrin, chlorantraniliprole, imidacloprid, and thiamethoxam to different A. pernyi strains. It was found that the lowest LC₅₀ value of the Liaocanda9 strain against beta-cypermethrin (0.008 mg/L) was significantly higher than that of the Kangda strain (0.0047 mg/L). Additionally, beta-cypermethrin exposure was associated with significant increases in detoxification and antioxidant enzyme activities in both strains. Transcriptomic analysis showed that differentially expressed genes (DEGs) were significantly enriched in pathways related to oxidoreductase activity and transmembrane transporter activity terms. Furthermore, these genes were differentially expressed following the beta-cypermethrin exposure. The dsRNA injection treatment effectively inhibited the expression of P450 genes, thereby reducing the tolerance of A. pernyi against beta-cypermethrin by 25.93–55.56%. Molecular docking predicted that beta-cypermethrin bound to ABCG1, ABCG5, and CYP9A22 with hydrogen bonds. These results indicate that ABC transporters and P450s contribute to the tolerance of A. pernyi against beta-cypermethrin. Full article

Botanical insecticides containing a mixture of plant essential oils (EOs) are considered suitable for the management of houseflies (M. domestica). The adulticidal efficacies of single EOs and mixtures of EOs, including lemongrass (C. citratus), star anise (I. verum), nutmeg (M. fragrans), and their components (geranial, trans-anethole, and α-pinene), against houseflies were determined in comparison to 2% (w/v) α-cypermethrin as the positive control and distilled water as the negative control. The mixture of star anise EO (1%) + geranial (1%) was the most effective adulticide, superseding single EOs, other combinations of EOs, and its active component, α-cypermethrin, and distilled water. This mixture was highly synergistic and was found to be over 74% more toxic than all single EOs and almost 2.6 times more toxic than α-cypermethrin. Furthermore, the tested EOs did not cause mortality in guppies (P. reticulata) or earthworms (E. fetida), and caused a maximum of 48% mortality in honeybees (A. mellifera) at 24 h; by contrast, α-cypermethrin led to 100% mortality in honeybees within 0.5 h and in guppies and earthworms within 24 h, although it had low toxicity toward houseflies. Thus, a mixture of star anise EO + geranial is a promising source of EO-derived insecticides for housefly control that is also safe for important non-target species. Full article

In this study, a comprehensive assessment of pesticide residues in fruits, vegetables, and derived products collected between 2022 and 2025 within the Apulia and Basilicata regions (Southern Italy) is reported. The analytical workflow combined QuEChERS extraction with Gas Chromatography coupled to Triple Quadrupole Mass Spectrometry (GC-QqQ-MS/MS) and Ultra-High-Performance Liquid Chromatography coupled to Heated Electrospray Ionization-Quadrupole Orbitrap Mass Spectrometry (UHPLC-HESI-Q-Orbitrap-MS). A total of 198 samples were analyzed, including fruits (51%), vegetables (35%), and processed products (14%). Approximately 60% of the samples originated from large-scale distribution networks (EU and non-EU imports), while 40% were derived from local production in Apulia and Basilicata. Validation parameters for both methods met the SANTE/11312/2021 and Commission Implementing Regulation (EU) 2021/808 performance requirements. Results showed that 76.8% of samples were free of quantifiable pesticides, while 23.2% contained residues below EU maximum limits, confirming high compliance and effective regional agronomic management in Apulia and Basilicata. The estimated daily intake and chronic hazard index values were below 100%, across all population groups, confirming the absence of chronic dietary risk. The integration of GC-QqQ-MS/MS and UHPLC-HESI-Q-Orbitrap-MS platforms ensured comprehensive chemical coverage and high selectivity, providing an effective regional surveillance model aligned with EU “Farm to Fork” food safety purposes. Full article

The evolution of resistance in mosquitoes to conventional insecticides such as pyrethroids presents a challenge to vector control. Thus, alternative active ingredients for insecticides to manage pyrethroid-resistant populations of mosquitoes are needed. The goal of this study was to evaluate the toxic and repellent efficacy of geraniol, a plant secondary metabolite, as a potential alternative for controlling pyrethroid-resistant Aedes aegypti. We found that addition of geraniol to rearing water of 1st instar larvae caused concentration-dependent mortality within 24 h in both strains. The resistance ratio of geraniol (2.8) was modest compared to that of cypermethrin (435.3). Topical application of geraniol to adult female mosquitoes caused dose-dependent mortality in both strains within 24 h. The resistance ratio of geraniol (1.1) was minimal compared to that for cypermethrin (457). In spatial repellency assays, geraniol repelled adult females from both strains in a dose-dependent manner. The repellency resistance ratio of geraniol (2.6) was modest compared to that for pyrethrum extract (>132). Our findings suggest that geraniol has potential use as a toxicant and repellent for controlling pyrethroid-resistant populations of Ae. aegypti. Full article

Aiming at addressing the lack of efficient, low-toxicity insecticides and precise application technologies in the current control of R. batava obscuriosa, this study intends to screen high-efficacy insecticides for UAV application and evaluate their field control effects, so as to provide a reference for the field control of R. batava obscuriosa. The residual film method was used to determine the laboratory toxicity of seven insecticides to adult R. batava obscuriosa. The LC₅₀ and LT₅₀ values of the seven insecticides were calculated. Based on these results, four high-efficacy insecticides were selected for UAV field efficacy testing. The control effects of different insecticides were evaluated through indicators such as population reduction rate, corrected control effect and fruit infestation rate after application. Laboratory toxicity results showed that 10% abamectin·beta-cypermethrin exhibited the strongest toxicity at 24 h (LC₅₀ = 22.108 mg/L). At 48 h after application, 5% emamectin benzoate was optimal (LC₅₀ = 5.486 mg/L). At 72 h after application, 10% broflanilide (LC₅₀ = 1.796 mg/L) and 10% abamectin·β-cypermethrin (LC₅₀ = 2.665 mg/L) performed best. Field test results indicated that the population reduction rate of 10% abamectin·β-cypermethrin reached 91.73% at 7 days after application, while the other three insecticides had population reduction rates above 80%, showing good overall control effect; at 15 days after application, 20% chlorfluazuron-thiamethoxam had the highest corrected efficacy (80.91%), and the fruit infestation rate of each insecticide group (24.75–27.49%) was significantly lower than that of the control group (58.08%). All four selected insecticides can effectively control the population of R. batava obscuriosa adults and can be used as quick- and long-acting insecticides against R. batava obscuriosa in production. Combined with UAV application technology, they can achieve efficient control of R. batava obscuriosa. Full article

The castor bean tick (Ixodes ricinus) is a widespread European ectoparasite and vector of multiple diseases that can impair cattle health and productivity. This study evaluated whether a single application of a gel microencapsulated acaricide (α-cypermethrin and permethrin) reduces I. ricinus infestation in dairy cows and affects milk yield. Twenty cows were allocated to treated and control groups; treated animals received one spray at the start of the grazing season, and tick counts were recorded daily for 196 days with monthly milk-yield measurements. Two activity peaks were observed (June and September–October) with reduced abundance in July–August; all control cows were parasitised, with daily counts of 1–18 ticks (median = 2). During the first month after treatment, the acaricide reduced tick numbers by around 80% versus controls (p < 0.001); efficacy declined over the ensuing months, and differences were negligible after about five months. No adverse effect on milk yield was detected (p = 0.38), and seasonal variation (p < 0.0001) and lactation stage (p < 0.001) were the primary determinants of production. Primiparous and young cows, as well as cows in mid-to-late lactation, tended to show higher levels of tick infestation. A single application of the gel microencapsulated product provided a significant reduction in tick burden during the first month after treatment in grazing dairy cows, without a negative impact on milk production, supporting its use in endemic areas. Full article

Mycterothrips glycines Okamoto (1911) (Thysanoptera: Thripidae) is rapidly increasing in fields, posing a new and potentially serious threat to soybean production in Northeast China. To clarify the population dynamics and screen effective insecticides against M. glycines, systematic monitoring and pesticide evaluation were conducted from 2024 to 2025. Occurrence dynamics were continuously monitored using yellow and blue sticky boards, while ten commonly used commercial insecticide formulations (thiamethoxam, clothianidin, sulfoxaflor, acetamiprid, imidacloprid, fenthion, pyridaben, abamectin, beta-cypermethrin, spinetoram) were hierarchically screened through laboratory bioassays, pot trials, and field spraying experiments. The results revealed a distinct ‘rise-and-fall’ occurrence pattern, with the initial, peak, and late occurrence periods occurring in mid-July, late July to early August, and mid-to-late August, respectively. Thiamethoxam and clothianidin exhibited the strongest toxicity against M. glycines (LC₅₀ values of 12.87 mg/L and 13.46 mg/L, respectively), achieving field control efficacies exceeding 85%, which were significantly superior to conventional agents such as imidacloprid and abamectin. The study identified the soybean flowering stage as the critical window for control, recommending preventive interventions when sticky trap monitoring indicates the initial population peak (around mid-July). This research fills the technical gaps regarding the occurrence dynamics of M. glycines and the lack of registered control products in China, providing essential support for precision monitoring and management of soybean thrips. Full article

Spodoptera frugiperda is a major agricultural pest both in Brazil and worldwide, with widespread resistance to synthetic insecticides. This study evaluated the toxicity and residual activity of toxic bait formulations combining 17 insecticides with the plant-based kairomone attractant Noctovi^® 43SB against S. frugiperda adults. Bioassays were conducted with 48 h-old, food-deprived adults. Toxicity was assessed by incorporating insecticides at 2% concentration into Noctovi^® 43SB. Residual activity was measured by applying toxic baits on cotton leaves and testing at 3, 7, 15, 21, and 30 days after application (DAA). Insecticides based on methomyl, spinetoram, spinosad, indoxacarb, malathion, and zeta-cypermethrin induced over 95% mortality. Methomyl showed the greatest toxicity (LC₅₀ = 322 mg a.i. L⁻¹; LC₉₀ = 1160 mg a.i. L⁻¹). Eleven insecticides maintained residual activity (≥70%) after 30 DAA, except malathion. Overall, toxic bait formulations combining Noctovi^® 43SB with methomyl, spinosad, spinetoram, or indoxacarb proved highly effective, offering both rapid and prolonged control of S. frugiperda adults. These findings highlight attract-and-kill as a promising tool for sustainable management of this pest. Full article

A new generation of insecticide-treated nets (ITNs) that incorporate the synergist piperonyl butoxide (PBO) has been shown to restore susceptibility to pyrethroids where P450 enzymes are the primary mechanism conferring the resistance. The present study evaluated the efficacy of YAHE 4.0, a PBO ITN, against wild free-flying Anopheles arabiensis in experimental huts in Lower Moshi, north-eastern Tanzania. It is the first evaluation of YAHE 4.0 in the country. Bio-efficacy evaluations, including susceptibility tests and cone bioassays, were conducted using the standard WHO guidelines. DuraNet Plus, a WHO-recommended PBO ITN, and Interceptor ITNs served as active and standard comparators, respectively. Unwashed and 20 times washed nets were subjected to experimental hut trials. Multiple logistic regression was employed to analyse experimental hut trial data. The results of the susceptibility testing showed that the An. arabiensis population of Lower Moshi was resistant to pyrethroids, but susceptible to organophosphates. Particularly, low mortality was recorded for cyhalothrin (2%) and alpha-cypermethrin (38%). Mortality rates to alpha-cypermethrin pirimiphos-methyl were 38% and 100%, respectively. The non-inferiority of YAHE 4.0 to DuraNet Plus ITN in terms of mortality and blood feeding was determined according to the WHO guidelines. The results for pooled unwashed and 20 times washed ITNs showed that YAHE 4.0 was superior to Interceptor ITN (adjusted odds ratio, AOR = 1.33; 95% CI = 1.04–1.69; non-inferiority margin, NIM = 0.68; p-value = 0.023) and non-inferior to DuraNet Plus (AOR = 1.02; 95% CI = 0.78–1.35; NIM = 0.72; p-value = 0.867) in terms of mortality. In terms of blood feeding inhibition for pooled unwashed and 20× washed ITNs, YAHE 4.0 was superior to both Interceptor ITN (AOR = 0.80; 95% CI = 0.64–1.00; NIM = 1.35; p-value = 0.049) and DuraNet Plus (AOR = 0.67; 95% CI = 0.52–0.86; NIM = 1.33; p-value = 0.002). Chemical analysis showed higher wash retention of active ingredients in YAHE 4.0 LLIN (88.9% for PBO and 94.9% for alpha-cypermethrin) compared to DuraNet Plus LLIN (89.2% for PBO and 90.5% for alphaypermethrin) before the hut trial. YAHE 4.0 LLIN demonstrated superior entomological efficacy and wash durability to DuraNet Plus and Interceptor LLINs, and fulfilled WHO non-inferiority criteria for mosquito mortality and blood-feeding inhibition. Therefore, YAHE 4.0 LLIN should be considered as an addition to the current list of pyrethroid-PBO nets used for control of pyrethroid-resistant vector populations with P450 enzymes as the main mechanism conferring resistance. Full article

Background: Solenopsis invicta, commonly known as the red imported fire ant (RIFA), is an important global invasive pest, and its management is challenging because of insecticide resistance and environmental problems. Methods: In this research, we applied transcriptomics to analyze the molecular responses of S. invicta worker ants exposed to different types of pesticides, beta-cypermethrin (BC) and the entomopathogenic fungus Cordyceps cicadae (CC), as well as to different concentrations of these pesticides. Results: A total of 2727 differentially expressed genes (DEGs) were identified across all samples. The number of DEGs in the BC treatment group was significantly higher than that in the CC treatment group (2520 vs. 433), and higher concentrations resulted in more DEGs (an increase of 47 in the BC group and 229 in the CC group). KEGG pathway analysis revealed that the DEGs were significantly enriched in lipid metabolism, carbohydrate metabolism, amino acid metabolism, signal transduction, and membrane transport. Immune-related gene analysis showed more general down-regulation (average FPKM value in BC 741.37 to 756.06 vs. CK 1914.42) of pathogen recognition genes (PGRP-SC2) under BC stress conditions, while CC treatment resulted in increases in expression of important immune effectors such as various serine proteases. Conclusions: Overall, this study provides useful insights into the molecular basis of responses to different pesticides in S. invicta and offers a basis to develop new approaches to control this pest. Full article

Pyrethroids, synthetic analogues of natural pyrethrins, are extensively used in agriculture and household pest control due to their high insecticidal activity and relatively low toxicity to mammals. Due to the presence of multiple chiral centres, many pyrethroids exist as complex mixtures of stereoisomers with significantly different biological activities, toxicities, and environmental behaviours. Consequently, accurate determination of these stereoisomeric forms, particularly compounds such as cypermethrin, is critical for food safety monitoring. Determining pyrethroid residues in food matrices presents a significant analytical challenge due to the structural diversity and stereochemical complexity of these compounds. This study presents the development of an analytical method for determining the stereoisomeric forms of cypermethrin and other synthetic pyrethroids in food matrices using both LC-MS/MS and GC-MS/MS techniques. The method meets the performance criteria outlined in SANTE/11312/2021 v2, demonstrating satisfactory recovery rates (91.6%), precision (RSDR 1.9%), and low limits of quantification (LOQ 0.010 µg/kg) for the quantification of alpha-cypermethrin. This approach offers a reliable tool for regulatory monitoring and risk assessment of pyrethroid residues, especially those with complex stereochemistry. Full article

The widespread cultivation of transgenic Bt cotton has elevated Apolygus lucorum (Meyer-Dür) to a major pest in cotton agroecosystems. Its rapidly developing resistance to insecticides poses a serious challenge to sustainable agriculture. In this study, we assessed the susceptibility of a field-collected population from Anyang, Henan Province, in relation to a laboratory-susceptible strain, to elucidate the present status and molecular basis of resistance to beta-cypermethrin. First, the toxicity of beta-cypermethrin to A. lucorum was assessed through a diet-incorporation method. Subsequently, the enzymatic activities of carboxylesterase (CarE) and glutathione S-transferase (GST) were measured, and the expression levels of CarE1 and GST1 were quantified by quantitative real-time PCR (qRT-PCR). Finally, the function of candidate genes was confirmed using RNA interference (RNAi) technology. The bioassays results indicated that the median lethal concentration (LC₅₀) for the laboratory and Anyang field strain were 343.34 mg/L and 700.45 mg/L, respectively. Following 48 h of exposure to the LC₃₀ of the susceptible strain, the mortality rate of the field population (20.00%) was significantly lower than that of the laboratory population (33.33%), suggesting an increase in resistance. The field population of A. lucorum exhibited significantly higher activities of CarE (1.61-fold) and GST (1.71-fold) compared to the laboratory strain, accompanied by 3.63- and 4.23-fold overexpression of the corresponding genes CarE1 and GST1. Spatiotemporal expression profiling revealed that CarE1 expression was highest in 4th–5th instar nymphs and adults, with predominant localization in the midgut, while GST1 expression peaked in 4th–5th instar nymphs and was abundant in the midgut and fat body. RNAi-mediated knockdown of CarE1 and GST1 significantly enhanced susceptibility to beta-cypermethrin in field populations, resulting in elevated mortality 48 h post-treatment compared to controls. In conclusion, the field population of A. lucorum has developed considerable resistance to beta-cypermethrin, strongly correlated with overexpression of CarE1 and GST1. These results deepen our understanding of metabolic resistance mechanisms and offer valuable insights for developing targeted pest control strategies. Full article

Chinese wolfberry (Lycium barbarum L.), a specialty crop with ecological, medical, and economic value in Ningxia province of China, is subject to severe damage from Aphis gossypii Glover. Currently, A. gossypii populations show extremely high-level resistance to beta-cypermethrin in the major wolfberry planting areas in Ningxia. The specific resistance mechanisms, however, are still not known. In this work, we collected a field A. gossypii strain (HSP) from a wolfberry orchard in Ningxia in 2021 using a single-time sampling method, and its resistance to beta-cypermethrin was determined to be extremely high (994.74-fold) as compared with that of a susceptible strain (SS). Then we explored the potential resistance mechanisms from two aspects, namely, metabolic detoxification and target-site alterations. Bioassays of beta-cypermethrin with or without a synergist showed that piperonyl butoxide (PBO) significantly increased the toxicity of beta-cypermethrin (4.72-fold) to the HSP strain, while triphenyl phosphate (TPP) and diethyl maleate (DEM) exhibited no significant synergistic effects. Correspondingly, the O-demethylase activity of cytochrome P450s in the HSP strain was 1.68-fold higher than that in the susceptive strain (SS), whereas changes in carboxylesterases and glutathione S-transferases activities were unremarkable. Also, fifteen upregulated P450 genes were identified by both RNA-Seq and qRT-PCR technologies, containing eleven CYP6 genes, three CYP4 genes, and one CYP380 gene. Especially, five CYP6 genes with high relative expression levels (>3.00-fold) were intensively expressed by beta-cypermethrin induction in the HSP aphids. These metabolism-related results indicate the key role of P450-mediated metabolic detoxification in HSP resistance to beta-cypermethrin. Sequencing of voltage-gated sodium channel (VGSC) genes identified a prevalent M918L mutation and a new G1012D mutation in HSP A. gossypii. Moreover, heterozygous 918 M/L and 918 M/L + G1012D mutations were the dominant genotypes with frequencies of 60.00% and 36.67% in the HSP population, respectively. Overall, VGSC mutations along with P450-mediated metabolic resistance contributed to the extremely high resistance of the HSP wolfberry aphids to beta-cypermethrin, providing support for A. gossypii control and resistance management in the wolfberry planting areas of Ningxia using insecticides with different modes of action. Full article