Search Results (121)

Growing pesticide use is linked to increased health risks for farmers across Africa, due to factors such as improper handling, insufficient knowledge, and lack of resources. To better understand these risk factors in Rwanda, where the majority of the population and most women are farmers, we held focus group discussions (FGDs) with 31 Sector Agricultural Officers (SAOs) and Sector Animal Resources Officers (SAROs) in five districts of Eastern Province. Among their views on this topic, we identified four core themes among the FGDs of (1) interconnected challenges, (2) shared exposure and health risks, (3) gender differences in risk behavior, and (4) transmission of knowledge, in addition to six pesticides—abamectin, cypermethrin, lambda-cyhalothrin, profenofos, mancozeb, and metalaxyl—most commonly used across all districts. Our findings suggest that Rwandan farmers may overestimate variety in the pesticides that they use and thus potentially contribute to problems such as pest resistance, underlining a critical need for integrated, locally informed approaches to pesticide management. This study also demonstrates the valuable role of extension officers in highlighting challenges related to pesticide use in farming communities and advancing research that engages with them. Full article

Woody plants in managed and natural ecosystems are increasingly exposed to arthropod pest pressure, posing challenges for sustainable plant protection. This study evaluates trunk injection as a pest management strategy in woody species, with emphasis on plant-mediated processes shaping interactions between host plants and herbivorous arthropods. Two experimental systems were investigated: a greenhouse experiment with Gleditsia triacanthos and a field experiment with Quercus petraea. Systemic active ingredients (acetamiprid and abamectin) were applied using both experimental and professional injection devices, and their effectiveness was assessed against Tetranychus urticae and a complex of foliar-feeding insects. In the greenhouse experiment, trunk injection reduced T. urticae populations compared with untreated controls and soil drench treatments, with reductions of 55.6–58.4% for larvae, 65.7–67.5% for eggs, and 28.7% for adults, although foliar application achieved higher suppression (up to 81.2% for eggs). In the field experiment, treatments reduced leaf discoloration (from 16.3% in control to 1.45–3.80%) and skeletonization (from 15.1% to 9.95–12.7%), with more moderate effects on defoliation. Differences among feeding guilds suggest that responses to systemically distributed compounds depend on feeding behavior and canopy position. Both pressurized and non-pressurized methods enabled uptake and translocation of active compounds within plant tissues. Localized injuries were observed at injection points, including internal necrosis. Overall, trunk injection represents a viable approach for pest management in woody plants, highlighting the role of plant-mediated processes in shaping treatment outcomes under contrasting conditions. Full article

Investigating the effects of sublethal pesticide doses on pest population succession and physiological metabolism is crucial for IPM and resistance delaying. This study evaluated sublethal effects of abamectin on Diaphorina citri using two-sex life tables, population modeling, and measurements of hormone levels, energy reserves, and gene expression to reveal its transgenerational impacts. Results showed dose-dependent and transgenerational effects: both F₀ and F₁ generations experienced prolonged development and reduced longevity under LC₂₅/LC₅₀ stress. Life-table parameters (r, λ, R₀, GRR, T) declined, and the model predicted a sharp population decrease after 60 days (from 10,357 to 1711 and 372 individuals under LC₂₅ and LC₅₀, respectively). The findings indicated that abamectin suppresses population growth by delaying development and limiting adult recruitment. Following abamectin treatment, hormone levels (20E and JH) showed dynamic fluctuations with delayed peaks in the treated groups, while energy reserves (glycogen and triglycerides) were generally reduced. Vitellogenin gene expression was mostly suppressed, except for a transient increase in Vg-1 and Vg-A1 (LC₂₅, day 9), whereas VgR was generally up-regulated except in the LC₂₅ group. Both LC₂₅ and LC₅₀ treatments suppressed D. citri development and reproduction by disrupting hormone balance and energy metabolism, without inducing hormesis. These findings provide a theoretical basis for optimizing field application strategies and support the use of abamectin in IPM programs to reduce outbreak risk and delay resistance development. 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

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

In 2024 and 2025, field populations of Aphis gossypii were collected from eight regions in Xinjiang to monitor their resistance levels to five commonly used insecticides: sulfoxaflor, acetamiprid, imidacloprid, abamectin, and chlorpyrifos. The mutation frequencies of five sites in the acetylcholinesterase (AChE) gene (S431F, V332A, A302S, G221A, F139L) and three sites in the β1 subunit of the nicotinic acetylcholine receptor (nAChR) (R81T, V62I, K264E) were also analyzed. The results showed that from 2024 to 2025, the eight A. gossypii field populations exhibited the highest resistance to imidacloprid (primarily moderate to high resistance), followed by acetamiprid (all moderate resistance). Resistance to abamectin and sulfoxaflor was relatively low, but sulfoxaflor resistance increased rapidly (from low resistance in 2024 to moderate resistance in 2025). All populations remained consistently susceptible to chlorpyrifos. Gene analysis revealed that the mutation rate of S431F in the AChE gene was nearly 100%, while that of V332A remained stable at approximately 30%. The mutation rates of A302S and G221A showed a slight increase, whereas the F139L mutation rate was extremely low (<1.00%). In the β1 subunit of nAChR, the mutation rates of R81T and V62I remained stable at around 50%, and the K264E mutation rate was extremely low (<1.00%). This study clarifies the resistance evolution patterns of A. gossypii to different insecticides and the variation characteristics of key resistance genes in Xinjiang, providing a scientific basis for the integrated resistance management of A. gossypii and the rational selection of effective insecticides. 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

The two-spotted spider mite, Tetranychus urticae Koch, is a major agricultural pest whose control is increasingly constrained by resistance to synthetic acaricides. This study evaluated the long-term field efficacy of three commercial entomopathogenic fungal (EPF) biopesticides—Velifer^® (Beauveria bassiana), Metab^® (B. bassiana + Metarhizium anisopliae), and Botanigard^® (B. bassiana)—against larval and protonymph stages of T. urticae on two host plants, Italian cypress (Cupressus sempervirens) and sweet orange (Citrus sinensis). Two foliar applications were conducted during the 2023 growing season (25 May and 25 July), and mite populations were monitored for 140 days after the final application. A randomized complete block design was used, and efficacy was calculated using the Henderson–Tilton formula. All EPF treatments significantly reduced mite populations compared with the untreated control throughout the monitoring period. Velifer consistently achieved the highest suppression of larval populations, particularly on C. sinensis, with efficacy comparable to the chemical standard. Botanigard showed more gradual but sustained population reduction over time, whereas Metab exhibited lower but stable efficacy in all cases. Treatment performance was strongly influenced by host plant species and mite developmental stage, with larvae consistently more susceptible than protonymphs. On C. sinensis, Velifer achieved the highest larval suppression (84.6%), comparable to the chemical standard abamectin, while Botanigard and Velifer were most effective on C. sempervirens. Survival analysis confirmed isolate- and host-dependent differences in hazard effects over time. These results demonstrate that EPF-based products can provide sustained, long-term suppression of T. urticae under field conditions, supporting their integration into integrated pest management programs. Full article

The objective of this study is to evaluate the effects of botanical oils on the mortality of the phytophagous mite Tetranychus urticae, the predatory mite Amblyseius swirskii, and on gas exchange in papaya seedlings. Two vegetable oils (soybean and corn), two essential oils (lavender and oregano), a synthetic pesticide (abamectin), and a control (water) were evaluated on papaya seedlings infested with T. urticae. In laboratory assays, within the first day after application, abamectin caused 100% mortality of T. urticae adults, followed closely by soybean (96%), corn (94.7%), and lavender (94.7%) oils. In A. swirskii, abamectin caused 100% mortality within 24 h; at 72 h, corn and lavender oils reached 96%, while oregano oil caused the least mortality (67.3%). In field trials, both abamectin and botanical oils statistically reduced eggs per leaf 24 h after application relative to the control, and a similar pattern was observed for nymphs 48 h after treatment. Botanical oils equaled abamectin in T. urticae adult suppression by 72 h, and soybean caused complete adult mortality by day 14. Regarding gas exchange, abamectin significantly affected the photosynthesis and transpiration processes. Thus, botanical oils represent viable biorational options for managing T. urticae in papaya, with lower ecological and physiological costs than abamectin. Full article

Potato (Solanum tuberosum L.) is the third most important food crop worldwide and a cornerstone of food security across the Andean region. However, its production is increasingly threatened by the potato psyllid Bactericera cockerelli (Šulc), the vector of Candidatus Liberibacter solanacearum, the causal agent of the purple-top complex associated with zebra chip disease, which severely reduces both tuber yield and quality. This study was conducted from September 2024 to February 2025 in the province of Huancabamba, Peru, to evaluate the efficacy of biological and chemical control agents against B. cockerelli under field conditions. A randomized complete block design was implemented with five treatments and four replicates, totaling 20 experimental units, each consisting of 20 potato plants (S. tuberosum L.), of which 10 plants were evaluated. Treatments included an untreated control (T0), a chemical control (thiamethoxam + lambda-cyhalothrin, abamectin, and imidacloprid) (T1), and three biological control agents: Beauveria bassiana CCB LE-265 (>1.5 × 10¹⁰ conidia g⁻¹) (T2), Paecilomyces lilacinus strain 251 (1.0 × 10¹⁰ conidia g⁻¹) (T3), and Metarhizium anisopliae (1.0 × 10¹⁰ conidia g⁻¹) (T4). Foliar applications targeted eggs, nymphs, and adults of the psyllid. Results indicated that B. cockerelli mortality across developmental stages was lower under biological treatments compared with T1, which achieved the lowest probability of purple-top symptom expression (46%) and a zebra chip incidence of 60.60%. Among the biological agents, M. anisopliae (T4) reduced incidence to 56.60%, while P. lilacinus (T3) demonstrated consistent suppression of nymphal populations. In terms of yield, T1 achieved the highest tuber weight (198.86 g plant⁻¹) and number of tubers (7.74 plant⁻¹), followed by T3 (5.08) and T4 (4.24). Nevertheless, all treatments exhibited low yields and small tuber sizes, likely due to unfavorable environmental conditions and the presence of the invasive pest. Overall, chemical control was more effective than biological agents; however, the latter showed considerable potential for integration into sustainable pest management programs. Importantly, vector suppression alone does not guarantee the absence of purple-top complex symptoms or zebra chip disease in potato tubers. Full article

Pesticides play key roles in modern agricultural activities. Optimizing pesticide deposition is essential for maximizing utilization efficiency and minimizing unintended environmental impacts. While electrostatic, hydrogen, and covalent interactions have been extensively studied to modulate pesticide adhesion to leaf surfaces, the potential of metal coordination bonding to enhance foliar deposition remains largely unexplored. In our work, abamectin-loaded PLA nanospheres coated in tannic acid (TA) (Abam@PLA) via the metal chelating ability of polyphenols (Abam@PLA-TA) were developed to improve abamectin retention on the surfaces of leaves. The chemical properties and morphological features of Abam@PLA-TA were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and fluorescent imaging. The foliar retention of Abam@PLA-TA demonstrated that the tannic acid coating could significantly improve the adhesion ability and deposition efficiency of pesticides for crop leaves, which was mainly attributed to the hydrogen bonds between the polyphenols of TA and the polar groups of the wax layer. Moreover, Abam@PLA-TA exhibited better photostability capacity compared to the abamectin technical concentrate, which helps to protect light-sensitive pesticides from ultraviolet (UV) decomposition. This strategy opens up a simple but powerful avenue for the design of foliage adhesive systems and a new opportunity for the efficient utilization of pesticides. Full article

Prostephanus truncatus is well known for causing extensive postharvest losses and threatening food security in tropical and subtropical regions. The reliance on synthetic insecticides has raised concerns about the development of resistance, environmental safety, food contamination, and human health, emphasizing the need for alternative management strategies. Thus, the present study evaluated the insecticidal efficacy of diatomaceous earth (DE) in the Protector formula alone and in combination with spinosad, abamectin, or the entomopathogenic fungus Beauveria bassiana against P. truncatus adults and their progeny production on maize under two temperatures (25 and 30 °C) at low concentrations. Bioassays revealed that DE or B. bassiana alone induced low mortality, while spinosad and abamectin single applications resulted in high mortality rates, achieving 100% after 21 days of exposure at 30 °C at the higher concentrations. The combined applications of spinosad or abamectin with DE resulted in complete mortality and progeny suppression at lower concentrations at 25 °C. Temperature had a significant influence in some cases. Overall, these findings demonstrate that DE, when combined with other natural insecticidal agents at low concentrations, especially spinosad and abamectin at specific temperatures, can provide highly effective control of P. truncatus, offering a promising strategy for integrated pest management (IPM) in stored maize. Full article

Integrated pest management (IPM) in tomato (Solanum lycopersicum L.) on the Ecuadorian coast represents a critical challenge, given that pest persistence has led producers to abandon the crop, generating significant losses. This study compared pest population fluctuations in greenhouse and open field conditions under realistic management conditions and free infestation, considering the influence of environmental factors and applications of biorational, semisynthetic, and synthetic pesticides. In open fields, infestations were high and sustained, exceeding treatment thresholds, while in greenhouses, levels were lower, attributable to the protection of the aphid netting. Product efficacy depended on the pest and the level of infestation: Azadirachta indica, Bacillus thuringiensis, and Beauveria bassiana were effective in low infestations; spinetoram and abamectin reached efficacies between 80 and 100% in moderate infestations; neonicotinoids had variable efficacy, ranging from 47.8% to 89.9%. Since the system determines the type of pest and the level of infestation, monitoring becomes a key tool for timely decision-making. The findings show that the greenhouse limits the entry of the main pest, Prodiplosis longifila. While it does not prevent the presence of smaller pests, such as thrips and white mites, the combination of physical barriers and low-toxicity pesticides significantly reduces populations, minimizing the number of applications and the use of more toxic insecticides. The proposed strategy provides solid evidence for the effective implementation of a greenhouse to reduce pest pressure and promote IPM in protected coastal systems in Ecuador. Full article

Feed and water scarcity are major challenges for the sustainability of livestock production, particularly in semi-arid regions with structural limitations in resource availability. In this context, the valorization of agro-industrial by-products contributes to circular agriculture, reduces waste, and promotes more efficient resource use, in line with the United Nations Sustainable Development Goals. This study evaluated the inclusion of partial mixed tomato residue (PMR) silage in sheep diets and its effects on productive performance, total water intake, and meat quality. Eighteen ewe lambs were assigned to two groups: control (concentrate and deferred pasture) and PMR (tomato residue silage and deferred pasture). The PMR silage had a pH of 3.97 and was mainly characterized by lactic and acetic acids, with minor amounts of propionic and butyric acids. The butyric acid concentration (8.9 g kg⁻¹ DM) slightly exceeded the recommended threshold (0.5% DM), suggesting some clostridial activity but remaining below levels associated with severe deterioration. Animals fed PMR silage showed a 36% higher dry matter intake (p = 0.001), with greater intake of total digestible nutrients and fiber. This translated into a 54% higher average daily gain (p = 0.02) and an 11% greater final body weight compared with the control group (p = 0.02). Dietary water intake was also higher in the PMR group, reducing direct water consumption from drinkers by 38% (p < 0.001). Meat quality parameters were unaffected by the diet. Pesticide residue screening by LC-MS/MS revealed no detectable levels of abamectin, cymoxanil, chlorothalonil, difenoconazole, or mancozeb in silage. In meat samples, only chlorothalonil was tested and it was not detected. However, the use of PMR silage increased direct energy demand due to transport and compaction, while feeding costs per unit of weight gain were reduced. Overall, PMR silage proved to be a safe, fermentatively stable, and effective feeding alternative that enhances performance, reduces direct water intake, and maintains meat quality, representing a viable strategy for small ruminant production in water-limited regions. Full article

Pine wilt disease, which is induced by pine wood nematode (PWN, Bursaphelenchus xylophilus), has caused huge economic and ecological losses. To overcome the drawbacks of chemical control against PWN, twenty compounds were screened, and a synergistic botanical–chemical combination was identified. A proportion of abamectin to rotenone of 7:3 (5.73 and 1.78 mg/L, respectively) achieved the highest co-toxicity coefficient of 231.09 with a median lethal concentration of 3.18 mg/L. It revealed 0% mortality in Pinus massoniana seedlings at 60 days post-treatment when applied at 400 times the synergistic concentration (2.29 g/L abamectin + 0.71 g/L rotenone) at 7 days after PWN inoculation. Furthermore, the synergistic combination significantly affected the physiological activity and population dynamics of PWN. Female oviposition was reduced by 71.92%, the egg hatching rates declined to 13.09 ± 0.02%, and head thrashing frequency was inhibited by 99.23 ± 0.01%. The enzymatic activities of peroxidase, acetylcholinesterase, succinate dehydrogenase, and glutathione S-transferase were significantly increased, while the population size declined by 96.17%. Transcriptomic and gene expression analyses suggested a potential “Na⁺/Ca²⁺/Cl⁻ ionic storm,” since the synergistic combination significantly activated genes associated with voltage-gated calcium channels, glutamate-gated chloride channels, and amiloride-sensitive sodium channels. These findings provide an eco-friendly strategy for PWN management via chemical control. Full article