Search Results (2,354)

Stenoma catenifer (Lepidoptera: Depressariidae), the avocado seed borer, represents a major phytosanitary threat in Andean avocado production systems. Egg parasitoids of the genus Trichogramma constitute promising biological control agents for this pest; however, their field-level compatibility with agrochemicals commonly used in avocado orchards remains largely uncharacterized. This study evaluated the side effects of 13 commercial pesticide formulations on Trichogramma exiguum (Hymenoptera: Trichogrammatidae) under two complementary exposure scenarios: (1) residual contact toxicity on adults and (2) susceptibility of parasitized Ephestia kuehniella (Lepidoptera: Pyralidae) eggs, following International Organisation for Biological Control IOBC/WPRS standardized methodology. Corrected adult mortality was assessed at 1 h and 24 h post-exposure, while parasitism expression at the pupal stage, adult emergence rate, and developmental time were recorded for preimaginal stages. At 24 h, abamectin, acephate, lambda-cyhalothrin, and metalaxyl caused 100% adult mortality (harmful), whereas potassium soap and hexythiazox were classified as moderately harmful. In Bioassay 2, potassium soap completely suppressed parasitism expression and adult emergence (0%), while neem extract showed no significant reduction relative to the water control. Developmental time to adult emergence ranged from 9.7 to 12.0 days across treatments, with no statistically significant differences among them. These results indicate that neem extract and the adjuvant dispersant are broadly compatible with T. exiguum, whereas neurotoxic insecticides and potassium soap are incompatible under both exposure scenarios. These findings provide an evidence-based compatibility hierarchy to guide the strategic integration of chemical inputs and augmentative biological control in avocado integrated pest management programs. Full article

Tuberculosis, malaria, and HIV are infectious diseases that have become major global health problems. Efforts to reduce the incidence and mortality of tuberculosis have undergone a long process, resulting in a significant annual decrease of up to 2%. In a single year, malaria cases can reach nearly 230,000,000, with up to 400,000 deaths worldwide. Meanwhile, approximately 37,000,000 people were living with HIV worldwide in 2020, with about 690,000 deaths due to AIDS reported in the same year. Within the framework of the Sustainable Development Goals (SDGs), particularly Goal 3 on good health and well-being, one of the key targets is to end the epidemics of tuberculosis, malaria, and HIV. This research examines the effects of various interventions on tuberculosis, malaria, and HIV coinfection. The interventions considered include preventive measures, mosquito nets, insecticides, contraception, tuberculosis treatment, malaria treatment, and antiretroviral (ARV) therapy for HIV. The mathematical model of tuberculosis, malaria, and HIV coinfection is well-defined, as it is proven to have non-negative solutions, to be bounded, and to remain within the positive invariant region. The tuberculosis, malaria, and HIV sub-models each have an asymptotically stable equilibrium when the basic reproduction number is less than one. Based on the results of numerical simulations of the sub-models, it can be observed that when the basic reproduction number exceeds one, the disease spreads throughout the population. Full article

The agricultural industry largely relies on conventional pesticides to maintain healthy, pest-free crops. Application of conventional insecticides is the go-to method for cultivating important food crops, such as corn and sorghum, free of Spodoptera frugiperda (fall armyworm) infestations. However, conventional insecticides have purported negative environmental and health impacts. Natural plant extracts, such as essential oils, are viewed as a promising alternative to conventional insecticides. In the current study, Dysphania ambrosioides (epazote) essential oil was embedded into an artificial diet and fed at two different concentrations to fall armyworms during a 10-day period. Final weights of the 5% epazote treatment group were statistically less (F₆₃₄₃ = 136.2 p < 0.001) than control groups. The 5% epazote treatment group also experienced the highest mortality rate (62%) of any treatment group (X² = 831.4, DF = 6, p < 0.001). Findings suggest that epazote essential oil has potential as an effective, natural insecticidal ingredient. This research is of importance to the fields of agronomy and health sciences. Full article

Since its first detection in 2010, Aedes albopictus has spread across northern Algeria, where vector control relies on the use of chemical insecticides. This study aimed to evaluate the susceptibility of Ae. albopictus populations from Algiers to commonly used larvicides and adulticides, as well as to characterize the underlying resistance mechanisms. Eggs were collected from three sites in Algiers. The susceptibility of larvae to temephos and Bacillus thuringiensis israelensis (Bti), as well as that of adults to permethrin, deltamethrin, malathion, and bendiocarb was evaluated using WHO bioassays. Genotyping of knockdown resistance (kdr) mutations was performed via PCR and sequencing. Metabolic resistance mechanisms were investigated using CDC bottle bioassays. The larvae were found to be susceptible to temephos and Bti. Bioassays on adults demonstrated susceptibility to deltamethrin, suspected resistance to permethrin, and resistance to malathion and bendiocarb. Genotyping revealed low frequencies of heterozygous kdr mutations (V1016G, I1532T, F1534C/S). Synergist assays highlighted the key role of esterases in malathion resistance, a minimal involvement of glutathione S-transferases and an unexpected antagonistic effect of cytochrome P450 monooxygenases. Although larvicides remain effective, resistance to organophosphates, carbamates, as well as suspected resistance to permethrin, has been detected. Esterase-mediated metabolic resistance and kdr mutations may contribute to this profile. These findings highlight the need for resistance monitoring and integrated vector control to ensure sustainable control of Ae. albopictus. Full article

The practical efficacy of Azadirachtin (AZA)—a botanical insecticide valued for its strong antifeedant activity—is often undermined by its poor environmental stability, arising from rapid photolysis and thermal decomposition. Herein, amino-modified mesoporous silica nanoparticles (MSNs) were employed as nanocarriers to encapsulate AZA, yielding the AZA@MSNs−NH₂ nanoinsecticide. Under UV irradiation (254 nm), the degradation rate of AZA@MSNs−NH₂ was more than 35% lower than that of commercial AZA after 24 h of exposure. In biosafety tests, MSNs at 50–800 mg/L enhanced cotton seed germination and seedling growth, whereas MSNs below 200 mg/L caused no observable harm to zebrafish survival. Free AZA (0.5–10 mg/L) showed limited efficacy in bioassays against Helicoverpa armigera and Apolygus lucorum, reducing larval weight gain only marginally in the former (mortality < 5%) and performing poorly against the latter. In contrast, AZA@MSNs−NH₂ significantly boosted both growth inhibition and lethal effects against both pests, yielding > 80% growth inhibition and 62.65% corrected mortality for H. armigera, as well as strong lethality toward A. lucorum. Overall, this work confirms that nanoformulation of AZA not only circumvents its physicochemical drawbacks but also boosts its insecticidal performance against cotton pests, supporting the advancement of sustainable cotton pest control. Full article

This review aims to highlight the rich biodiversity of plants with acaricidal properties in Africa and the potential for harnessing them for the development of eco-friendly acaricides. Terrestrial plant-derived bioactive substances hold huge potential as cost-effective and eco-friendly insecticides that can serve as a suitable alternative to chemical pesticides. Ticks and tick-borne diseases (TTBDs) constitute a serious challenge to animal and human health globally, necessitating the need for effective control measures. However, the use of chemical acaricides, the mainstay of tick control, is no longer sustainable due to the development of multiple acaricide resistance, economic constraints, and environmental and public health concerns, necessitating the exploration of phytochemical acaricides as a viable option. In Africa, the rich plant biodiversity remains largely underexplored and underutilized for TTBDs control. Our bibliographical review identified 144 plant species from 48 families across 27 African countries that have been assessed in various in vitro assays. These studies report that these plant species possess phytochemicals with acaricidal properties, causing over 50% mortality or repellency on various tick developmental stages. Plant species belonging to the Asteraceae (n = 23), Lamiaceae (n = 17) and Fabaceae (n = 11) from several African countries were reported to possess effective anti-tick properties. Bioactive substances and essential oils, such as the tannins, flavonoids, steroids, terpenoids, camphor, camphene, 1,8-cineole (eucalyptol), alpha-pinene and more were the most frequently isolated compounds, attesting to the rich biodiversity of plants possessing phytochemicals with strong prospects for use in tick control. Despite these encouraging findings, none so far has been translated or formulated into an anti-tick product for commercial use. Therefore, we advocate for robust continental and regional collaborations to coordinate the bioprospecting of anti-tick ethnobotanicals, ultimately leading to the development of cost-effective and eco-friendly natural products for tick control. Full article

The pea aphid (Acyrthosiphon pisum) is a destructive phloem-feeding pest of alfalfa. Its overreliance on chemical insecticides necessitates the development of sustainable, plant-based resistance strategies. Plant flavonoids are important in induced defense, but their dynamic responses to aphid feeding and subsequent insecticidal effects remain unclear. Using the highly resistant alfalfa variety ‘Gannong No. 5’ (GN5), this study integrated behavioral assays, performance bioassays, untargeted and targeted metabolomics, and exogenous flavonoid feeding assays to investigate how pea aphid infestation alters flavonoid metabolism and thereby affects aphid performance. Bioassays confirmed strong antibiosis of GN5 against A. pisum. Behavioral choice assays showed that, at 2 h post-release, aphids significantly avoided plants pre-infested for 12 h and 48 h, but not those pre-infested for 24 h; by 8 h post-release, they significantly avoided all pre-infested plants regardless of infestation duration. Prolonged pre-infestation (48 h) also reduced average fecundity per female. Non-targeted metabolomics revealed substantial metabolic reprogramming after 48 h of aphid feeding, with most flavonoids and isoflavonoids significantly upregulated. Targeted metabolomics identified 28 flavonoids, among which only sakuranetin and chrysin were significantly upregulated after 48 h, indicating their specific induction. Finally, performance bioassays confirmed insecticidal effects in a concentration-dependent manner: sakuranetin at 0.1 μg/μL reduced reproduction, and at 10.0 μg/μL reduced survival; chrysin at 0.1 μg/μL reduced both survival and reproduction. Collectively, these results demonstrate that pea aphid feeding triggers the induction of specific defensive flavonoids in GN5, which may contribute to antibiosis. This study provides a theoretical basis for exploring flavonoid-based approaches in sustainable aphid management. Full article

The red imported fire ant (Solenopsis invicta Buren) is a destructive invasive pest, and conventional chemical control faces challenges related to environmental contamination and resistance development, highlighting the need for novel control agents and greener management strategies. In this study, pyrethrins-mediated silver nanoparticles (Pyr-AgNPs) were synthesized via a green route, characterized, and evaluated for their insecticidal activity, environmental stability, and metabolic effects on S. invicta workers. Bait bioassays showed that Pyr-AgNPs exhibited high toxicity to S. invicta, causing 100% cumulative corrected mortality at 500 mg·kg⁻¹ after 9 days of feeding, with a 5-d LC₅₀ of 116.83 mg·kg⁻¹. Exposure assays further demonstrated that Pyr-AgNPs had good environmental stability and residual efficacy, as bait containing 1000 mg·kg⁻¹ Pyr-AgNPs still caused 100% cumulative corrected mortality after 9 days following 96 h of outdoor exposure, significantly outperforming the pyrethrins treatment. LC-MS-based untargeted metabolomic analysis revealed that treatment with Pyr-AgNPs markedly altered the metabolic profile of S. invicta workers, with 607 differential metabolites identified, mainly belonging to organic acids and derivatives, lipid and lipid-like molecules, amino acids and peptides, cofactors, and redox-related metabolites. Pathway enrichment analysis indicated that these metabolic disturbances were primarily associated with energy metabolism, redox homeostasis, and membrane lipid metabolism. Overall, these findings provide preliminary mechanistic clues into the toxicity of Pyr-AgNPs and support their potential application in the sustainable management of S. invicta. Full article

Perfluorohexanesulfonic acid (PFHxS) is a per- and polyfluoroalkyl substance (PFAS) frequently detected in aquatic environments, while chlorpyrifos (CPF) is a widely used organophosphate insecticide. Although their individual toxicity is well described, their combined effects remain poorly understood. Here, we evaluated the effects of CPF (0.7 to 700 µg/L), alone or in combination with PFHxS (10 µg/L), in zebrafish embryos. Survival, hatching, malformations, locomotor activity, oxidative stress, apoptosis, and gene expression were assessed after five days of exposure. CPF reduced survival in a concentration-dependent manner, with moderate enhancement under co-exposure, while hatching success was unaffected. Deformities increased with CPF concentration, which remained consistent with PFHxS co-exposure, suggesting toxicity was mediated by CPF. Locomotor activity was largely decreased in a concentration- and phase-dependent manner. No significant changes were observed in ROS levels or apoptosis. Gene expression analysis revealed upregulation of neurotoxicity-related markers (ache, gfap, shha, syn2a), particularly at intermediate CPF concentrations and under co-exposure. Oxidative stress-related genes showed differential responses, with sod1 upregulated and cat downregulated only in the combined treatment. Overall, combined exposure did not substantially enhance toxicity compared with CPF alone, suggesting that CPF was the main contributor to the observed effects, whereas PFHxS had limited influence. Full article

Callosobruchus maculatus (Fabricius, 1775) is a major postharvest pest of stored legumes, causing significant quantitative and qualitative losses. This study evaluated host preference, biochemical determinants of susceptibility, and the insecticidal efficacy of plant powders and aqueous and ethanolic extracts against C. maculatus among selected pulse species. In free-choice assays, oviposition preference did not correspond with developmental success, as Phaseolus vulgaris Linnaeus, 1753, received the highest number of eggs but supported minimal adult emergence, whereas Vigna radiata (Linnaeus) A. Jussieu, 1954, exhibited the highest level of infestation and seed damage. Biochemical analysis revealed correlational patterns: higher carbohydrate and lipid contents were positively associated with infestation and seed weight loss, whereas fiber content showed a negative association with pest performance. Protein content was correlated with oviposition, while moisture and fiber were associated with reduced developmental success. Plant-derived treatments significantly affected all biological parameters of C. maculatus in a concentration- and time-dependent manner, with the exception of sex ratio. Among the tested botanicals, Azadirachta indica A. Jussieu (1830) consistently showed the highest toxicity, with the lowest LC₅₀ values across exposure periods. Ethanolic extracts showed greater insecticidal activity than aqueous extracts, indicating solvent-dependent extraction of bioactive compounds. Mortality increased progressively with exposure duration, accompanied by decreasing LC₅₀ values, suggesting cumulative toxic and developmental effects. Overall, the results demonstrate that host suitability is governed by the interaction between nutritional composition and structural seed traits, while botanical extracts, particularly those from A. indica, offer effective, eco-friendly alternatives for managing C. maculatus in stored legumes. Full article

Co-exposure to insecticides and heavy metals alters the way the chemicals affect the aphid. This interaction can induce synergism through enzymatic inhibition of the insect, increasing mortality, or antagonism through competition for cellular receptors. The aim of this study was to determine the synergistic or antagonistic effect of four insecticides and five heavy metals on the median lethal concentrations (LC₅₀ and LC₉₀) and their toxic efficiency between 24 and 48 h post-exposure to the bird cherry–oat aphid under laboratory conditions. The four pesticides were acetamiprid, imidacloprid, emamectin benzoate, and thiamethoxam. The five heavy metals were Cr, Ni, Pb, Cd, and Cu. The results revealed LC₅₀ and slope values for all four tested insecticides against the aphid. After 24 and 48 h from treatment, acetamiprid was the most toxic compound according to LC₅₀ values, followed by emamectin benzoate, thiamethoxam, while imidacloprid was the least toxic one. The results indicated that thiamethoxam was synergized by Cr, Cu, Cd, Ni, and Pb by 18.31, 5.36, 74.12, 4.58, and 225.46-fold, respectively, as compared with LC₅₀ values of thiamethoxam alone. This finding indicated that Pb was the most effective heavy metal in synergizing thiamethoxam. The results indicated that the toxicity of imidacloprid increased by adding each of the tested heavy metals except for Cu as compared with LC₅₀ of imidacloprid alone. Results showed that LC₅₀ value of each insecticide decreased with Cd as compared with LC₅₀ value of the insecticide alone at both 24 h and 48 h. Under the conditions of this study, it can be concluded that the Cd acted as a synergist for all tested insecticides. Full article

Juvenile hormone (JH) analog insecticides are widely used in pest management because of their ability to disrupt insect growth and metamorphosis; however, the molecular mechanisms linking endocrine disruption to metabolic dysregulation remain incompletely understood. In addition to their established roles in diapause and developmental regulation, JH signaling pathways have also been implicated in carbohydrate and lipid metabolism. In the present study, we investigated the effects of two JH analogs, pyriproxyfen and hydroprene, on the migratory locust, Locusta migratoria, with particular emphasis on lipid metabolic regulation and the function of midgut-enriched fatty acid-binding protein gene (Mg-FABP). Bioassays were performed to evaluate insecticidal activity, and transcriptomic analyses were conducted to identify differentially expressed genes associated with endocrine signaling and lipid metabolism. Functional characterization of Mg-FABP was further performed using RNA interference (RNAi) and Oil Red O staining assays. In addition, the tertiary structure of LmMg-FABP was predicted using AlphaFold 3, and molecular docking analyses were carried out to investigate its interactions with fatty acid ligands. Both pyriproxyfen and hydroprene caused approximately 70% mortality in locust nymphs and induced significant transcriptional changes in pathways related to hormone signaling and lipid metabolism. Transcriptomic analysis revealed pronounced downregulation of Mg-FABP following JH analog exposure. RNAi-mediated silencing of Mg-FABP significantly reduced lipid droplet accumulation in the fat body, indicating that Mg-FABP plays an essential role in lipid transport and metabolic homeostasis in L. migratoria. Structural analyses further demonstrated that LmMg-FABP possesses a conserved tertiary structure highly similar to FABP homologs from other insect species. Molecular docking identified key amino acid residues involved in fatty acid binding and suggested that hydrophobic interactions are critical for ligand stabilization within the binding cavity. Collectively, our findings demonstrate that pyriproxyfen and hydroprene disrupt insect development not only through endocrine imbalance but also through perturbation of Mg-FABP-associated lipid metabolic pathways. This study provides new mechanistic insight into the coordinated interaction between hormonal signaling and lipid metabolism during JH analog exposure and identifies FABP-mediated lipid transport as a potential molecular target for the development of more selective insect growth regulators. Full article

Bacillus thuringiensis Cry toxins are well known for their high insecticidal activity against Lepidoptera, Diptera, and Coleoptera and have been widely used in Bt transgenic crops. However, their activity against Hemipteran aphids remains relatively low. Identifying novel Cry proteins and elucidating their action mechanisms can facilitate the development of effective aphid control strategies. In this study, we found that ingestion of Cry2Ab12 did not kill Myzus persicae adults but significantly reduced their offspring number and exerted a lethal effect on M. persicae nymphs. After identifying Cry2Ab12 toxin-binding proteins in M. persicae, we further characterized the interaction with Obg-like ATPase 1 (OLA1), a conserved protein involved in growth regulation. Bio-layer interferometry (BLI), ELISA, and enzyme activity assays revealed that Cry2Ab12 and OLA1 do not interact directly. Interestingly, heat shock protein 60 (HSP60) was shown to mediate the interaction among Cry2Ab12, HSP60, and OLA1, leading to inhibition of OLA1 enzymatic activity. Based on these findings and bioinformatics simulations, we proposed a mechanistic model for Cry2Ab12 toxicity against M. persicae: upon ingestion of a sufficient amount of Cry2Ab12, the formation of the Cry2Ab12–HSP60–OLA1 complex impairs the cellular stress response, disrupts normal OLA1 expression, and ultimately restricts larval growth and development, resulting in lethality. This study provides new insights into the action of Cry toxins in aphids and offers a basis for developing enhanced aphid biocontrol strategies. Full article

Seed enhancement technologies have emerged as promising approaches to improve seedling growth and nursery performance of forest tree species. This study evaluated the effects of combining seed priming and seed coating technologies with beneficial microbial inoculants on the seedling quality of Falcataria falcata (L.) Greuter & R.Rankin. Fourteen treatments, including hydropriming (HP), gibberellic acid (GA₃), Rhizobium sp., Trichoderma sp., endomycorrhiza, polymer coating, nutrients, fungicide, and insecticide, were assessed under nursery conditions. Seedling quality was determined using the number of roots, number of nodules, root-to-shoot ratio, vigor index I, and vigor index II. Significant differences among treatments were observed for all measured parameters (p < 0.001). The treatment HP + GA₃ + Rhizobium sp. + polymer coat + fungicide (T13) produced the highest number of roots (31.76 roots seedling⁻¹), indicating enhanced root development. Meanwhile, HP + endomycorrhiza (T4) resulted in the highest number of nodules (5.49 nodules seedling⁻¹), root-to-shoot ratio (0.593), and vigor index I (2055.57), reflecting improved biomass allocation and overall seedling quality. Principal component analysis explained 71.9% of the total variation and revealed distinct associations between treatments and growth attributes. Treatments containing Rhizobium sp. were primarily associated with root proliferation and seedling vigor, whereas endomycorrhizal treatments were linked to nodulation and balanced biomass development. The results demonstrate that integrating microbial inoculants with seed priming and coating technologies can significantly enhance seedling quality, even when germination responses are similar among treatments. These findings highlight the potential of biologically enhanced seeds as a sustainable strategy for producing vigorous planting materials suitable for plantation forestry, reforestation, and landscape restoration programs. Full article

Laurinterol, a halogenated sesquiterpene produced by red algae of the genus Laurencia, is one of the most characteristic compounds within the laurane and cyclolaurane families. This review compiles and examines current knowledge on laurinterol, integrating evidence on its occurrence, biosynthesis, biological activities, and structural features. Within a functional and ecological framework, laurinterol is proposed as an archetypal Smart Secondary Metabolite (SSM), a concept that reflects the convergence of structural singularity, high abundance within its biosynthetic context, broad biological activity, multi-target interactions, and ecological or chemotaxonomic relevance. This perspective highlights its role in adaptive processes within producing organisms and associated trophic networks. Laurinterol exhibits a broad bioactivity profile, including antimicrobial, antimycobacterial, cytotoxic, antiparasitic, enzyme inhibitory, antifouling, and insecticidal or repellent effects. Structure–activity relationship (SAR) studies remain limited and are mainly developed in specific models, particularly against Naegleria fowleri. The current intellectual property landscape related to laurinterol, including patent applications, granted patents, and technological development trends, is also examined. Overall, this review positions laurinterol as a structurally distinctive and functionally relevant marine metabolite within chemical ecology and marine natural products research. Full article