Control Of Spodoptera Frugiperda Research Articles

Functional characterization of two odorant‐binding proteins to sex pheromones in Spodoptera frugiperda

AbstractThe primary function of odorant‐binding proteins (OBPs) is thought to be binding and transporting odorants molecules. The research on the molecular mechanisms of SfruOBPs binding with sex pheromones is beneficial to the prevention and control of Spodoptera frugiperda (S. frugiperda). Herein, two screened SfruOBPs (Sfru10933 and Sfru21187) were knocked down by RNA interference, and then the changes in electroantennogram (EAG) and behavioral responses of male mutants to their main sex pheromone components were recorded. Upon interfering with Sfru10933, the EAG response and behavioural preferences of males to sex pheromones were significantly reduced or eliminated. The interference with Sfru21187 resulted in a weakening of the behavioural preference, while the EAG response remained unchanged. However, the co‐interference of Sfru10933/Sfru21187 led to a significant reduction in the EAG activity of male to sex pheromones. These results reveal that Sfru10933 and Sfru21187 play a crucial role in sex pheromone recognition, and there may be a synergistic effect between them. Furthermore, these results will help clarify the perception of sex pheromones by S. frugiperda, which may provide new targets for the development of mating inhibitors in the future.

Some Biological Aspects and an Attempt to Control Spodoptera frugiperda (J.E. Smith) Using Some Selected Essential Oils Under Laboratory Conditions

Some Biological Aspects and an Attempt to Control Spodoptera frugiperda (J.E. Smith) Using Some Selected Essential Oils Under Laboratory Conditions

A new biocontrol agent against old enemies: The potential of Trichogramma foersteri for the control of Spodoptera frugiperda and Spodoptera eridania

Species of the genus Trichogramma Westwood (Hymenoptera: Trichogrammatidae) are widely used for pest control, highlighting the importance of exploring new species for the advancement of biological control programs. The study aimed to evaluate the efficacy of Trichogramma foersteri Takahashi, a recently discovered species, in controlling Spodoptera frugiperda (JE Smith) and S. eridania (Stoll), two significant pests of numerous cash crops. Over three days, the research examined parasitism, non-reproductive mortality, and emergence rates for both pest species. Trichogramma foersteri demonstrated effective parasitism, reducing 144.1 ± 6.0 eggs (one layer) and 55.4 ± 4.0 eggs (two layers) of S. frugiperda, as well as controlling 150.7 ± 5.6 eggs of S. eridania. Non-reproductive effects contributed significantly to mortality, causing the demise of 192.6 ± 4.7 and 118.6 ± 3.8 eggs in one and two layers of S. frugiperda, and 294.7 ± 7.0 eggs in S. eridania. Within three days, T. foersteri controlled approximately 334.2 ± 7.6 and 174.0 ± 4.0 eggs of S. frugiperda in one and two layers, respectively, and 445.4 ± 7.2 eggs of S. eridania. The highest emergence of T. foersteri occurred on the first day of evaluation, with 80.4 % for S. frugiperda and 23.0 % for S. eridania. These findings underscore the potential of T. foersteri as an effective control agent for both pests and provide valuable insights for the development of sustainable pest control strategies.

Biological control of Spodoptera frugiperda J.E. Smith and Schistocerca piceifrons piceifrons Walker using entomopathogenic fungi

ctive: Evaluate the biological effectiveness of native entomopathogenic fungi to control Spodoptera frugiperda and Schistocerca piceifrons piceifrons, as well as the natural incidence of parasitoids in S. frugiperda.
 Design/Methodology/Approach: Six strains of Metarhizium anisopliae (A1, A2, A3, A4, A5, and A6) and three strains of Isaria fumosorosea (B4, B5, and B6) were collected. S. frugiperda larvae were inoculated with all the isolated strains of Metarhizium and Isaria; while, the nymphs of S. p. piceifrons were inoculated with strains A1, A5, A6, B4, and B5. Mortality (%) and natural incidence of parasitoids in S. frugiperda larvae were evaluated. Mortality was analyzed using a one-way ANOVA and a comparison of means (Duncan; ɑ = 0.05) in the INFOSTAT 2021 software. Parasitism was reported with descriptive statistics (%).
 Results: Strains A1, A6, and B6 caused the highest mortality (86.6-90.0 %) in S. frugiperda larvae. Strains A1, A5, A6, and B6 caused the highest mortality in nymphs of S. p. piceifrons (90-100 %). Two families of parasitoids were recorded: Tachinidae (Diptera; 7.8 %) and Braconidae (Hymenoptera). Wasps of the genus Meteorus sp. account for 92.2 % of the latter family.
 Study Limitations/Implications: The biological effectiveness evaluations of the entomopathogenic fungi were carried out under laboratory conditions. The results must still be validated on the field.
 Findings/Conclusions: Strains A1, A5, and A6 showed a good control of the S. p. piceifrons nymphs. Strain B6 is a biological control alternative for S. p. piceifrons and S. frugiperda, since it recorded the highest mortality for both species.

Effectiveness Of Liquid Smoke from Oil Palm Solid Waste Against Spodoptera frugiperda (lepidoptera: noctuidae)

Indonesia is one of the largest producers of palm oil commodities in the world. Massive palm oil production to meet high demand can pose risks in increasing waste production. The processing of solid palm oil waste into liquid smoke through pyrolysis is carried out as an effort to mitigate environmental damage caused by greenhouse gases. Components in liquid smoke can be utilized as natural insecticides. This research aims to determine the potential of liquid smoke from solid palm oil waste, namely fiber and frond, to control Spodoptera frugiperda. The testing method uses a Randomized Complete Block Design (RCBD) with 11 treatments repeated three times. Liquid smoke application is done by dipping the feed, which is then given to S. frugiperda instar II. The results show that liquid smoke from fronds causes higher mortality in S. frugiperda compared to liquid smoke from fibers. At a concentration of 4%, liquid smoke from fronds and fibers caused S. frugiperda mortality of 63.33% and 40%, respectively. Liquid smoke application also suppressed feed consumption by 72.98% lower than the control and caused an extension of time from instar II-VI at the 4% application concentration. The use of liquid smoke from palm fronds and fibers can be used as an insecticide as one of the pest control techniques and a solution for utilizing palm oil waste.

The complete genome and biological activity of a novel Spodoptera litura multiple nucleopolyhedrovirus for controlling Spodoptera frugiperda

The fall armyworm, known as Spodoptera frugiperda, is a notorious invasive pest wreaking havoc on agricultural crops globally. In the course of this study, a novel variant of the S. litura multiple nucleopolyhedrovirus (SpltMNPV-T0) was isolated from S. litura larvae found on tobacco plants in China. This research delved into the molecular and biological characteristics of SpltMNPV-T0. Electron microscopy revealed that this variant exhibited the characteristics features of a baculovirus. The complete genome of SpltMNPV-T0 was 137,925 bp in length, with a G + C content of 42.88 %, housing a total of 130 open reading frames (ORFs). Phylogenetically, this variant was similar to the published genome of the SpltMNPV-G2 strain, aligning itself with the Alphabaculovirus group II. However, it distinguished itself from the SpltMNPV-II in terms of sequence similarity (76.45 %), shared ORFs (only 63 genes in common), and gene order (exhibiting inversion and reordering). Crucially, SpltMNPV-T0 demonstrated notable effectiveness in controlling third-instar larvae of S. frugiperda and S. litura. Furthermore, the virulence of crude SpltMNPV-T0 matched that of the commercially available virus-based pesticide (SpltMNPV-KY), as evident in terms of mortality rates and speed of kill. These findings yield valuable insights into the molecular biology and functional genomics of this newly discovered variant, characterized by its high virulence. Such knowledge holds promise for advancing bio-control technologies aimed at mitigating the destructive impact of the pest S. frugiperda.

The use of baculovirus Spodoptera SfMNPV alone and combined with herbicides and adjuvant to control Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae)

Four independent experiments were carried out to evaluate the use of Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV) alone and mixed in different combinations with herbicides (atrazine and tembotrione) and adjuvant (soybean oil) to control Spodoptera frugiperda in maize. Experiments evaluated S. frugiperda mortality (%) under controlled conditions (26 ± 2 °C, relative humidity of 70 % ± 10 %, and 14:10 h L:D photoperiod) after feeding using a treated artificial diet (experiment 1) and maize leaves (experiment 2), both immediately and four hours after spraying the studied treatments (experiment 3). An additional experiment evaluated plant damage caused by S. frugiperda in the field (visual observation) on various days after spraying the tested treatments (experiment 4). The addition of the herbicide atrazine did not reduce the efficiency of SfMNPV in S. frugiperda control in any of the experiments. Thus, SfMNPV could be used in a tank mix with this herbicide, which would be economically attractive to farmers, facilitating SfMNPV adoption in the field. In contrast to atrazine, the herbicide tembotrione and the adjuvant (soybean oil) had an antagonistic interaction with SfMNPV, but only when sprayed four hours after preparation. Thus, the combination of SfMNPV with tembotrione and soybean oil can also be used by farmers if sprayed immediately after mixing with the baculovirus.

Supressão de acasalamentos e redução de danos de Spodoptera frugiperda (J. E. Smith, 1797) no algodoeiro

The control of Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) in cotton (Gossypium hirsutum L.) has been limited by the rapid development of resistance to insecticides and Bt toxins. The fall armyworm has become increasingly present in cotton fields, becoming a major problem for growers. Therefore, the demand for new and more sustainable tools for managing this pest has increased in recent years. Ideally, the new tool should be compatible with other available control tactics, such as the use of Bt plants, and it should be implemented following IPM principles. In this study, we tested the efficacy of a liquid pheromone formulation for the Fall armyworm control in Bt and conventional cotton varieties in the Brazilian Midwest. Our results showed that the capture of insects in traps has been reduced by 85% in areas treated with pheromone compared to control suggesting high levels of mating suppression. Pheromone treatment also resulted in 70% less damage to cotton reproductive structures when compared to areas not treated with the pheromone in conventional cotton. Moreover, applying pheromone provided an additional benefit to Bt cotton, resulting in 85% damage reduction. Our results show the effectiveness and feasibility of mating disruption with pheromone as an important management tactic for Lepidopterans in cotton. However, no significant differences were found in yield in the conditions tested. These results represent a potential key step toward developing more sustainable tools for pest management in Brazil.

Genome-Wide Scanning Loci and Differentially Expressed Gene Analysis Unveils the Molecular Mechanism of Chlorantraniliprole Resistance in Spodoptera frugiperda.

Chlorantraniliprole has been widely used to controlSpodoptera frugiperda, but it has led to the development of chlorantraniliprole resistance. Multiomics analysis of strains with two extreme traits helps to elucidate the complex mechanisms involved. Herein, following genome resequencing and application of the Euclidean distance algorithm, 550 genes within a 16.20-Mb-linked region were identified from chlorantraniliprole-resistant (Ch-R) and chlorantraniliprole-susceptible (Ch-Sus) strains. Using transcriptome sequencing, 2066 differentially expressed genes were identified between Ch-R and Ch-Sus strains. Through association analysis, three glutathione S-transferase family genes and four trehalose transporter genes were selected for functional verification. Notably, SfGSTD1 had the strongest binding ability with chlorantraniliprole and is responsible for chlorantraniliprole tolerance. The Ch-R strain also increased the intracellular trehalose content by upregulating the transcription of SfTret1, thereby contributing to chlorantraniliprole resistance. These findings provide a new perspective to reveal the mechanism of resistance of agricultural pests to insecticides.

EFICACY OF ENDJULULU-KAPASSARINHO (DATURA STRAMONIUM) IN CONTROLLING SPODOPTERA FRUGIPERDA IN MAIZE (ZEA MAYS L.) IN VITRO

In order to control Spodoptera frugiperda in the maize crop in the laboratory, vegetative parts of the Edjululu-Kapassarinho plant were harvested, crushed and the concentrations formed: T0=0ml, T1=20ml, T2=40ml, T3=60ml, T4=80ml and T5=100ml. The caterpillars were collected and fasted for two hours before being placed in the treatment concentrations of each vegetative part for observation at times of 24, 48, 72, 96 and 120 hours respectively. The results showed that the fruit was the most active ingredient (Atropine, Hyoscyamine Scopolamine), followed by the stem, root and leaves, representing 60%, 27%, 24% and 13% respectively, with the leaves proving to be repellent to the caterpillars. Caterpillar mortality increased after 24 hours at all concentrations, showing 96% mortality with the stem-based extract, 98% with the leaf-based extract, 90% with the fruit-based extract and 79% with the root-based extract. In the statistical analysis observed at 5%, there was significant variation between treatments. In view of the results, the aqueous plant extract of the Endjululu-Kapassarinho plant (Datura Stramonium) proved to be effective in controlling the cartridge caterpillar in the maize crop in vitro.

Formulation of Matrine Oil-Based Suspension Concentrate for Improving the Wetting of Droplets and Spraying Performance

Matrine is an efficient, low-toxicity, and environmentally friendly botanical pesticide; however, it is mainly applied as a soluble concentrate (SL) with a limited utilization rate that is unsuitable for ultra-low-volume spraying and unmanned aerial vehicles. Therefore, a matrine formulation (such as an oil-based suspension concentrate, OD) is more effective. In this study, matrine ODs were prepared with three kinds of emulsifiers (VO/02N, VO/03, and VO/01). The storage stability, suspensibility, viscosity, surface tension, contact angle, droplet density, fraction of coverage, maximum retention, indoor control, effect of adhesion tension, and adhesion work of matrine ODs were studied. All three types of matrine ODs had favorable stability, and the wetting and spraying performance of the matrine ODs were more effective than those of the matrine SLs. Among the three types of matrine ODs, the viscosity, wettability, spray performance, and maximum retention of the suspension made with emulsifier VO/03 were superior to those of the other two emulsifiers, and they were more effective in controlling Spodoptera frugiperda. Increasing the solution concentration improved the spreading velocity of the droplets on the solid surface and the wettability. The matrine OD prepared from emulsifier VO/03 had the most effective wettability and spraying properties, and it can be used for ultra-low-volume spraying and aerial application. This study offers new insights into the efficient use of plant-based pesticides.

Diamide insecticides targeting insect ryanodine receptors: Mechanism and application prospect

As a Lepidoptera pest, Spodoptera frugiperda has become one of the major migratory pests causing significant damage to crops. It should prevent and control Spodoptera frugiperda with strong reproductive ability, adaptability, and migration ability, and reduce economic losses as much as possible. Chemical insecticides are mainly used in the emergency control of Spodoptera frugiperda. Diamide insecticide is a kind of pesticide that specifically targets the ryanodine receptor of Lepidopteran pests, which makes it safe, effective, targeted, and low toxicity to mammals. So, it is one of the most concerned and fastest-growing pesticide products after neonicotinoid pesticides. Intracellular Ca2+ concentration can be regulated by ryanodine receptors, and the continuous release of Ca2+ eventually leads to the death of pests and achieve the insecticidal effect. This review introduces in detail diamide insecticides that mainly play roles in stomach toxicity, as well as its specific target-ryanodine receptor, and analyzes how the diamide insecticide acts on the ryanodine receptor and how its mechanism of action can provide a theoretical basis for the rational use of highly effective insecticides and solve the resistance problem. Moreover, we also propose several recommendations for reducing resistance to diamide insecticides, and provide a reference for chemical control and resistance studies of Spodoptera frugiperda, which has broad development prospects in today's increasingly concerned about the ecological environment and advocating green environmental protection.

Eco-friendly deacetylated chitosan base siRNA biological-nanopesticide loading cyromazine for efficiently controlling Spodoptera frugiperda

Spodoptera frugiperda is a serious threat to various crops, such as corn and rice, and results in severe economic losses. Herein, a chitin synthase sfCHS highly expressed in the epidermis of S. frugiperda was screened, and when interfered by an sfCHS-siRNA nanocomplex, most individuals could not ecdysis (mortality rate 53.3 %) or pupate (abnormal pupation 80.6 %). Based on the results of structure-based virtual screening, cyromazine (CYR, binding free energy −57.285 kcal/mol) could inhibit ecdysis (LC50, 19.599 μg/g). CYR-CS/siRNA nanoparticles encapsulating CYR and SfCHS-siRNA with chitosan (CS) were successfully prepared, as confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and 74.9 mg/g CYR was characterized in the core of CYR-CS/siRNA by high-performance liquid chromatography and Fourier transform infrared spectroscopy. Small amounts of prepared CYR-CS/siRNA containing only 1.5 μg/g CYR could better inhibit chitin synthesis in the cuticle and peritrophic membrane (mortality rate 84.4 %). Therefore, chitosan/siRNA nanoparticle-loaded pesticides were useful for pesticide reduction and comprehensive control of S. frugiperda.

EFEKTIVITAS EKSTRAK DAUN SIRIH HUTAN (Piper aduncum L.) DENGAN PELARUT ORGANIK DALAM MENGENDALIKAN ULAT GRAYAK JAGUNG (Spodoptera frugiperda J. E. Smith) DI LABORATORIUM

Corn (Zea mays L.) is one of the most important food crops in the world after rice and wheat.There were various problem in crop production, one of which is the attack of fall armyworms (Spodoptera frugiperda J. E Smith). The alternative technique to control this was using botanical pesticide from forest betel leaf (Piper aduncum L.). This study aimede to obtain an effective concentration of forest betel leaf extract to control fall armyworm. This research was carried out at the Plant Pests Laboratory of the Faculty of Agriculture and the Laboratory of Natural materials and minerals, Faculty of Engineering, Riau University for 3 months from July to September 2021. The study consisted of six treatments 0%, 0.2%, 0.4%, 0.6%, 0.8%, 1% and four replications This research was arranged by Completely Randomized Design (CRD). The results showed that the use of forest betel leaf extract had a significant effect on the mortality of Spodoptera frugiperda larvaeConcentration of 0.8% is effective in controlling Spodoptera frugiperda larvae because it caused mortality at about 80% with an initial time of death was 1 hour after application and a lethal time of 50 at 13.5 hours after application.

Control of Spodoptera frugiperda on Fresh Corn via Pesticide Application before Transplanting

Background: Pesticide application before transplanting crops has been widely used in rice as an economical and effective method for reducing the use of chemical pesticides. This study focused on the feasibility of the application of pesticides before transplanting in a fresh corn nursery to control Spodoptera frugiperda. Methods: Three pesticides, including 35% Chlorantraniliprole WDG, 6% Spinetoram SC, and 3% Emamectin Benzoate WDG, combined with Polyorganosilicon (HTY-A8) or special flight additives (MF) as synergists were used and their toxicity was determined in the larvae of S. frugiperda feeding on sweet corn in the third leaf stage treated with 5 and 25 times the conventional field application concentration. The best combinations were tested in the field. The results showed that S. frugiperda exhibited high sensitivity to the three pesticides. The period of pest control validity of 35% Chlorantraniliprole WDG and 6% Spinetoram SC in the larvae was about 20 days, while that of 3% Emamectin Benzoate WDG was much shorter. The active component content of Chlorantraniliprole in the corn leaves was significantly higher than that of Emamectin Benzoate and Spinetoram. The pest control effects of Chlorantraniliprole were significantly promoted by HTY-A8 and MF. The field experiment showed that the control effect on S. frugiperda could last for 17 days by spraying Chlorantraniliprole or Spinetoram at 25 times the conventional concentration before transplanting, Furthermore, this method could reduce the amount of active ingredient to 4/5 or 3/4 of that found in a single field spray or seed coating treatment, respectively. Conclusions: This study puts forward a new method to effectively control S. frugiperda in the seedling stage of fresh corn.

Eco-friendly O-carboxymethyl chitosan base chlorfenapyr nanopesticide for effective pest control and reduced toxicity to honey bees

Enhancing pesticide selectivity is one of the important strategies to improve pesticide utilization and protect non-target organisms. Herein, a pH-controlled release carrier was prepared to enhance insecticidal activity and reduce toxicity to bees by polysaccharide materials O-carboxymethyl chitosan (O-CMCS) and crosslinker‑sodium tripolyphosphate (TPP). Chlorfenapyr (CF) was encapsulated through crosslinking and self-assembled to form a stable nanopesticide (CF@O-CMCS) with a loading ratio of 5.27 %. CF@O-CMCS had excellent pH release dependency. In 36 h, only 26.39 % of the CF in the CF@O-CMCS was released at pH 5.0, whereas 95.28 % was released at pH 10.0. Treated for 48 h with 2.5 mg.ai/L, CF@O-CMCS was 73.33 % more effective at controlling Spodoptera frugiperda larvae than CF SC (Suspension), which was only 40.00 % effective. The lethal concentration 50 % (LC50) of 11.41 mg/L in CF@O-CMCS was four times lower than that of 2.71 mg/L in CF SC at 96 h, making it safer for worker bees. Additionally, CF@O-CMCS treated the gut of worker bees had considerably lower contents of chlorfenapyr and tralopyril (1.13 and 0.59 mg/kg) than CF SC (3.22 and 1.91 mg/kg) group. In consideration of its eco-friendly, enhanced bioactivity, and low toxicity to worker bees, CF@O-CMCS will have a broad application prospect in sustainable agriculture.

Cyclosporin A as a Source for a Novel Insecticidal Product for Controlling Spodoptera frugiperda.

The fall armyworm (FAW), Spodoptera frugiperda, causes substantial annual agricultural production losses worldwide due to its resistance to many insecticides. Therefore, new insecticides are urgently needed to more effectively control FAW. Cyclosporin A (CsA) is a secondary metabolite of fungi; little is known about its insecticidal activity, especially for the control of FAW. In this study, we demonstrate that CsA shows excellent insecticidal activity (LC50 = 9.69 μg/g) against FAW through significant suppression of calcineurin (CaN) activity, which is a new target for pest control. Combinations of CsA and indoxacarb, emamectin benzoate, or Vip3Aa showed independent or synergistic toxicity against FAW; however, the combination of CsA and chlorantraniliprole showed no toxicity. Sublethal doses of CsA led to decreases in FAW larval and pupal weight, pupation, emergence, mating rates, adult longevity, extended development of FAW larvae and pupae and the pre-oviposition period of adults, and increases in the proportion of pupal malformation. Importantly, CsA treatment reduced FAW ovarian size and female fecundity, which suggests that it has great potential to suppress FAW colony formation. Taken together, these results indicate that CsA has high potential as an insecticide for controlling FAW.

Effectiveness of Neem Oil and Jatropha Oil in Controlling Spodoptera frugiperda (J.E Smith) on Maize in the Republic of Chad

Upon the evidence of its invasion in Chad in 2018, Spodoptera frugiperda has become a serious threat to maize production, thereby prompting farmers to a massive use of chemical pesticides to reduce its damage. However, given the adverse negative effects of chemical pesticides on human health and the environment, alternatives to chemical control are highly sought. In that respect, the effectiveness of Neem oil and Jatropha oil, two bio pesticides widely acknowledged for their insecticidal properties, was evaluated in the field in comparison with the chemical insecticide, Emamectin benzoate, in a Fisher Blocks design with 4 treatments and 4 replicates. The mean larval density per 25 plants was significantly the lowest (P < 0.0001) on Emamectin benzoate-treated plants(1.13 ± 0.70), followed by Jatropha oil (6.13 ± 0.87) and Neem oil treatments (7.13 ± 0.80) while the highest density was recorded on the untreated plants (12.31 ± 0.87). Similarly, the infestation rates were significantly lower on plots that received the chemical insecticide or the bio pesticides compared to the control plots (P < 0.0001). Foliar and ear damage scores were also significantly lower on the treated than on the control plots (P < 0.0001); and the number of ears attacked was significantly higher on the untreated control than on the other treatments. Maize grain yields were significantly higher in the treated plots compared to the control plots (P < 0.001). Yield gains over the control were 132.57%, 90.91% and 72.73% respectively for Emamectin benzoate, Jatropha oil and Neem oil treatments. It appears, therefore, that the use of Jatropha oil or Neem oil could significantly contribute to an effective and sustainable management of S. frugiperda on maize in Chad, thereby calling for the need for further investigations in that area in the frame of integrated pest management of this pest.

PH/redox/α-amylase triple responsive metal-organic framework composites for pest management and plant growth promotion

The development of stimuli-responsive controlled release formulations is a promising strategy to enhance the utilization efficiency and reduce the environmental pollution of pesticides. In this work, a smart pH/redox/α-amylase triple stimuli-responsive pesticide delivery system was constructed by bonding carboxymethyl starch (CMS) with metal-organic frameworks (MIL-101(Fe)–NH2 nanoparticles) which loaded with CAR (CAR@MIL-101(Fe)-CMS nanoparticles). The results indicated that the loading capacity of CAR@MIL-101(Fe)-CMS nanoparticles for CAR was approximately 18.3% and the CMS attached on the surface of CAR@MIL-101(Fe)–NH2 nanoparticles could protect CAR from photolysis effectively. Meanwhile, the coated CMS and metal-organic framework structure of the nanoparticles could be decomposed and consequently release pesticide active ingredients on demand when CAR@MIL-101(Fe)-CMS nanoparticles were metabolized by glutathione and α-amylase in the insect alkaline midgut. The bioactivity survey confirmed that CAR@MIL-101(Fe)-CMS nanoparticles had a longer duration in controlling Spodoptera frugiperda larvae compared to CAR suspension concentrate. In addition, the MIL-101(Fe)-CMS nanocarriers were safe for the growth of maize and could be used as fertilizer to promote the growth and development of crops. Thus, this smart stimuli-responsive pesticide-fertilizer all-in-one combination strategy has great potential in pest management.

Preparation and characterization of emamectin benzoate nanocapsules based on the dual role of polydopamine.

Developing pesticide-controlled release formulations with foliage adhesion has become the focus of current research in the field of crop protection. In this study, an excellent adhesive nanocapsule loaded with emamectin benzoate (Eb@PDA) was prepared via emulsion interfacial polymerization based on the self-polymerization ability and adhesion properties of polydopamine (PDA). The physicochemical properties of the Eb@PDA were characterized by scanning electron microscopy, transmission electron microscopy, particle size statistics, Fourier transform infrared spectroscopy and X-ray diffraction. The Eb@PDA presented a regular spherical shape, with an average particle size of 163.8 nm. Compared with conventional formulations, it had higher pesticide-loading content (34%) and excellent adhesion onto corn leaf. In addition, Eb@PDA showed sustained-release characteristics, facilitating the release of Eb at low pH and high temperature. Eb@PDA could effectively protect Eb against photodegradation and had a longer effective period for controlling Spodoptera frugiperda and Spodoptera exigua. Furthermore, acute toxicity tests showed that the 50% lethal concentration (LC50 ) was 80.91 and 57.91 mg kg-1 at 7 and 14 days, respectively, indicating a lower toxicity of the Eb@PDA to earthworms. The cells (L02) treated with Eb@PDA showed a higher cell viability but a lower apoptosis rate (only 5.75%), demonstrating the lower cytotoxicity of the Eb@PDA. The self-prepared Eb@PDA could be used as a formulation with the advantages of slow release, UV shielding, strong leaf adhesion, superior insecticidal properties, sustained effectiveness and biosafety. It will also facilitate the development of an efficient and safe pesticide delivery system. © 2022 Society of Chemical Industry.