Insecticidal effects of essential oils from traditional repellent plants on Aedes mosquitoes, vectors of arboviral diseases in Gabon.

Synthetic insecticides have been widely used for pest control but cause environmental issues such as pesticide residues, soil contamination, and resistance. As a result, there is a need for eco-friendly alternatives. Essential oils (EOs) are renewable, biodegradable, and non-persistent, making them promising candidates for natural insecticides. This study explores the potential of essential oils from the heartwood of Taiwania flousiana Gaussen, sourced from Tengchong, Yunnan. The chemical composition of T. flousiana essential oils was analyzed, displaying their diversity of chemical composition. Assessment of insecticidal activity against various pests revealed their broad-spectrum insecticidal activity. Afterwards we assessed their biochemical effects on Armigeres subalbatus, measuring esterase-α, esterase-β, SOD, LPO, and GST levels. Toxicity to non-target organisms, including Nicotiana tabacum, Danio rerio, and Apis mellifera, was also evaluated. Computational simulations identified four key bioactive compounds, with two dominant compounds isolated and characterized, laying the foundation for further studies. EOs of T. flousiana exhibit a broad spectrum of insecticidal activity, coupled with a remarkably low impact on non-target organisms. This suggests they could serve as an eco-friendly substitute for synthetic insecticides. This finding is significant for developing greener pest control strategies. © 2025 Society of Chemical Industry.

Active constituent nonacosane from Sphaeranthus indicus (Asterales: Asteraceae) leaves as a potent larvicidal agent against Aedes aegypti (Diptera: Culicidae) and Culex quinquefasciatus (Diptera: Culicidae).

Synthetic insecticides are recognized as a major factor contributing to the global decline in insect abundance and diversity. Within this context, anthranilic diamides have gained increasing market share in Europe since 2018. We investigated the second-generation diamide cyantraniliprole, which induces aberrant cytoplasmic calcium release in honeybee skeletal muscle cells. In vivo assays demonstrated that acute contact toxicity varied with exposure site, being more severe when applied to the abdomen, antennae, or ventral thorax compared with the dorsal thorax. Following thoracic exposure to sublethal doses, continuous 21-h monitoring revealed a dose-dependent alteration of behavior, with a reduction in locomotor activity, including maximal velocity and total distance traveled. Notably, at the lowest concentration, antennal exposure elicited stronger behavioral impairments, indicating potential disruption of sensory processing and environmental cue perception. Importantly, cyantraniliprole and its parent compound, chlorantraniliprole, also triggered anarchic calcium mobilization in mammalian skeletal muscle fibers, highlighting potential cross-taxa effects. These results strengthen previous evidence of diamides toxicity in bee cardiomyocytes and neurons and emphasize significant gaps in current risk assessment frameworks. Collectively, our findings indicate that anthranilic diamides represent not only an ecological threat to pollinators but also raise concerns for mammalian health, warranting more stringent evaluation of this insecticide class.

Botanical insecticides represent environmentally acceptable alternatives to synthetic products, and botanical insecticides represent environmentally acceptable alternatives to synthetic insecticides, which are regulated in the European Union. Owing to their rapid biodegradation into non-toxic compounds and selectivity toward beneficial organisms, botanical pesticides are well suited for implementation into integrated pest management (IPM) programs. However, the plant protection market includes both effective and ineffective botanical insecticides. In this study, we evaluated the efficacy of nine botanical insecticides sold in the European Union against the aphid Metopolophium dirhodum. The products IPW®, Limocide J®, NATUREN Careo®, Oroganic®, Polysect GYO®, Pyregard®, and Rock Effect New® demonstrated a mortality rate of between 85.33% and 100%. We simultaneously assessed their safety for non-target organisms, specifically, the key aphid predators Aphidoletes aphidimyza and Chrysoperla carnea. All effective products were classified as harmless to A. aphidimyza. NATUREN Careo®, Pyregard®, and Rock Effect New® were also harmless to C. carnea, whereas IPW®, Limocide J®, and Polysect GYO® were slightly harmful, and Oroganic® moderately harmful. These results will contribute to the rational selection of botanical insecticides suitable for use in integrated and ecological plant protection systems. All experiments were conducted under laboratory conditions.

Large-scale forest pest management has traditionally relied on aerial spraying; however, increasing regulatory restrictions and environmental concerns have limited its application in many regions. Unmanned Aerial Spraying System (UASS) platforms for aerial spraying have developed intensively in the last decade for pesticide application in agricultural crops but remain scarcely explored within the forestry sector. This study evaluates the feasibility of UASS-based spraying platforms for forest pest control. We tested a multi-rotor agricultural UASS in two different forest conditions: broadleaf and conifer stands. Both biological and synthetic insecticides were sprayed against two contrasting forest pests, Lymantria dispar and Adelges laricis. Defoliation and infestation intensity were used to assess treatment efficacy post-application. Results indicated differences in operational productivity between forest stand types, with higher treatment efficacy observed for L. dispar. Despite the correct dosage delivered by the UASS, the target organism showed a limited biological response in the conifer pest. In conclusion the use of UASSs in forest ecosystems is conditioned by forest-specific factors; however, these technologies show potential to be aligned with interventions targeting early-stage pest outbreaks.

Abstract BACKGROUND Insecticide application is necessary to control navel orangeworm ( Amyelois transitella ) in California tree nuts. Coverage is problematic because of height, and application timing can be problematic due to logistical challenges combined with grower reaction time. Bioassays using contact toxicity were conducted to characterize both spray coverage and the duration of control for air application for a period of 14–28 days, and contrast air application with ground sprays. RESULTS Ground application caused higher mortality than air application at a critical height of 3.7–4.3 m, and its duration of control was superior, based on higher mortality at 21 days. In one study, the mortality resulting from ground application remained constant at 89% for 21 days, whereas the average mortality for air application fell to 62%, although this was still satisfactory. There was a rapid decline in contact toxicity between 4 and 7 days after application by air. The mortality observed with air application did not depend on the water volume used because there was no difference between 93.5 L ha −1 and 280.6 L ha −1 . CONCLUSION The focus of this study on contact toxicity is the first step toward establishing a baseline for this route of exposure in tree nuts, and additional baselines are needed for adulticidal and ovi‐larvicidal activity. Air application was capable of providing high initial mortality but its duration needs to be extended. Improving coverage and application timing will become more important as California phases out the use of synthetic insecticides and makes the transition to insecticides solely dependent on ingestion toxicity. Published 2026. This article is a U.S. Government work and is in the public domain in the USA.

Abstract The Pear psylla, Cacopsylla pyri L. (Hemiptera: Psyllidae), is the main pest of pears in all pear-growing regions of Turkey as well as in Antalya province (southwestern part of Turkey). Its control mainly relies on the use of synthetic chemical insecticides; however, in last decade, desired levels of control have not been achieved due to development of resistance to these insecticides. Previous studies have shown that entomopathogenic fungi (EPFs) may be a good alternative to pesticides to suppress pear psylla populations. Therefore, the objectives of this study were: (i) to isolate native EPFs from naturally infected individuals of pear psylla in Korkuteli county of Antalya province, (ii) to identify the collected EPF isolates, and (iii) to assess the effectiveness of these isolates against various developmental stages [eggs, young (1st and 2nd instars) and older (3rd and 5nd instars) nymphs, and adults of the pest under laboratory conditions. A total of 19 fungal isolates, including 12 Beauveria bassiana (Balsamo) Vuillemin (Deuteromycota: Hyphomycetes), 3 Penicillium raistrickii Smith, 2 P. chrysogenum Tom and 2 Aspergillus ochraceus Wilhelm (Ascomycota: Eurotiomycetes)] were recovered from 63 fungal-infected psyllid cadavers during a two-year survey. In initial screening tests, 9 B. bassiana isolates, producing ≥ 20% mortality in the nymphal (young or older) stages of C. pyri , were also confirmed by molecular identification and included in the virulence assays for further evaluation against the pest. All 9 isolates were tested at three different conidial concentrations (1 × 10 5 , 1 × 10 6 and 1 × 10 7 conidia/ml), using spray method. The results of virulence assays showed that all 9 B. bassiana isolates had low ovicidal and adulticidal activity (both egg and adult mortalities were below 20%) while they caused significant mortalities on young nymphs. Of the 9 B. bassiana isolates tested, two isolates (AKBBPN2 and AKBBPN6) were the most virulent, causing 94.2 and 92.7% mortalities, respectively, in young nymphs within 14 days at the highest concentration (1 × 10 7 conidia/ml). The findings of the current study indicated that these two B. bassiana isolates from C. pyri nymphal cadavers may provide an essential basis for the development of bioproducts, as well as a promising alternative method for controlling the pest.

Potato cultivation in North-East India is significantly affected by many soil-borne insect pests like cutworms, white grubs and oriental army ants, resulting in significant yield and economic losses. The incidence of these pests is apparent both in the hills and the plains of the region. Potato growers mostly combat these pests with the help of synthetic insecticides; however, excessive reliance on these insecticides has resulted in ecological imbalance, health hazards and unsustainable pest management practices, particularly in the organically inclined Northeastern region. To address this issue, a long-term research initiative was undertaken to develop and validate an Integrated Pest Management package for potato. This eco-friendly and economically viable package integrates cultural, physical, biological, indigenous and need-based chemical practices which effectively reduce pest-induced losses, minimizes pesticide misuse and promote sustainable and profitable potato production in NE India.

The excessive use of synthetic insecticides in the phytosanitary protection of oil palm poses risks to public health and the environment. The aim of this study was to compare the efficacy of four (4) biopesticides against Oryctes monoceros, a pest responsible for delayed growth and, in some cases, the death of young oil palm plants. After obtaining larvae and adults from insect rearing, four biopesticides (A, B and C) at different concentrations (3.7×10–3 g/mL, 6.8×10–3 g/mL, and 1.2×10–2 g/mL), and biopesticide D (1.4×10–3 g/mL, 2.7×10–3 g/mL, and 4.8×10–3 g/mL) were first evaluated on Oryctes monoceros larvae. The larvae were exposed to the toxic effects of 100 mL of each prepared solution applied to 500 g of moistened wood sawdust. Among the four biopesticides tested, only biopesticide D, based on azadirachtin, showed high lethal efficacy, causing elevated larval mortality comparable to that of the reference insecticide. The respective lethal dose causing 10% mortality and lethal dose causing 50% mortality (LD50) values of 6.03×10–4±2.46×10–1 g/mL and 2.38×10–3±9.16×10–2 g/mL were lower, indicating higher efficacy. Compared to the reference synthetic insecticide cypermethrin, biopesticide D against adults showed an LD50 and a lethal dose causing 90% mortality (LD90) of 7.04×10–3±7.36×10–2 g/mL and 2.34×10–2±2.11×10–1 g/mL, respectively, while Cypermethrin yielded an LD50 and LD90 of 3.90×10–6±2.58×101 g/mL and 1.49× 10–4±1.75×101 g/mL. These results demonstrate the significant insecticidal activity of the biopesticides tested, particularly biopesticide D, against both larvae and adults of Oryctes monoceros. This product could be used as an alternative to synthetic chemical pesticides in the management of this pest.

Dependence on synthetic insecticides for controlling Spodoptera frugiperda has led to various adverse effects, including pest resistance, mortality of non-target organisms, and environmental pollution. These concerns necessitate the development of alternative control strategies, such as botanical insecticides that are both effective and environmentally friendly. Therefore, this study aimed to evaluate the toxicity and potential synergistic interactions of a hexane extract mixture of Piper retrofractum (Pr) and Annona squamosa (As) against second-instar larvae of S. frugiperda. Toxicity assays were conducted using the feed residue method in a completely randomized design with five extract mixture ratios of Pr:As (3:1, 2:1, 1:1, 1:2, and 1:3 w/w), each replicated five times. The results showed that the 2:1 (w/w) ratio was the most effective combination, yielding the lowest LC50 and LC95 values of 0.03% and 0.12%, respectively, at 96 hours after treatment. A higher proportion of Pr in the extract mixture tended to produce faster and more pronounced lethal effects on S. frugiperda larvae, and vice versa. The 2:1 (w/w) ratio also exhibited strong and stable synergistic interactions at all observation times at both LC50 and LC95 levels. This enhanced effectiveness is likely attributable to synergistic interactions among the active compounds present in each extract. These findings indicate that a mixture of P. retrofractum and A. squamosa extracts at a 2:1 (w/w) ratio has strong potential as an effective and efficient botanical insecticide to support the implementation of sustainable integrated pest management strategies.

Dichlorodiphenyltrichloroethane (DDT), one of the earliest and most extensively used synthetic insecticides, has become a persistent organic pollutant of global concern due to its high recalcitrance and hydrophobicity (resulting in its poor water solubility and long-term accumulation in soils and sediments). In this study, 207 bacterial strains were isolated from DDT-contaminated soils and screened for their ability to grow on DDT-containing media. Among them, 10 strains exhibited remarkable tolerance and growth, with strain T006 showing the highest potential for DDT degradation. Further experiments demonstrated that T006 exhibited strong and progressive DDT-degrading activity, removing over 70% of DDT within 8 weeks of culture. Comprehensive phenotypic, chemotaxonomic, and genome-based analyses - including 16S rRNA gene and rpoD gene phylogeny, average nucleotide identity (ANI), and digital DNA-DNA hybridization (dDDH) - confirmed that strain T006 represents a novel species, designated as Pseudomonas vietnamensis. The discovery of Pseudomonas vietnamensis T006 expands the known diversity of DDT-degrading bacteria and provides a promising microbial resource for the development of effective bioremediation strategies targeting organochlorine pesticide-contaminated environments.

Aims: The aim of the study was to evaluate the larvicidal potentials of H. suaveolens on Anopheles mosquito larvae. Study Design: Experimental research work. Place and Duration of Study: Leaves were collected from Ezza North and Ikwo Local Government Areas of Ebonyi State Nigeria. While the research was carried out at Applied Biology Departmental Laboratory of Ebonyi State University Abakaliki, International Centre for Ethnomedicine and Drug Development (InterCEDD) Nsukka, and Central Science laboratory of University of Nigeria Nsukka all in Nigeria, Between October 2023 to November 2024. Methodology: Leaves of the plant were collected, air-dried, grounded at the International Centre for Ethnomedicine and Drug Development (InterCEDD). The dried leaves were extracted using absolute ethanol and distilled water at different grammage of 300g/1500mL, 200g/1000mL, 100g/500mL, 50g / 300mL. Phytochemical screening and Quantitative analysis of the plant leaves were done while Bioassay experiments were conducted with third- and fourth-instar Anopheles larvae at extract doses of 1 g and 2 g, monitored at five-minute intervals over 120 minutes. Results: The results revealed the presence of alkaloids, flavonoids, tannins, phenolics, terpenoids, steroids, and saponins. Quantitative analysis indicated particularly high concentrations of phenolics (8278 mg/100 g) and terpenoids (1324.26 mg/100 g). Results of Bioassay experiment showed dose- and time-dependent larval mortality, with ethanolic extracts achieving 100 % mortality within 45–60 minutes and significantly lower EC₅₀ values compared to aqueous extracts. Conclusion: These findings suggest that ethanol more effectively extracts hydrophobic bioactive compounds such as terpenoids and flavonoids responsible for larvicidal activity. This study underscores H. suaveolens as a potent, natural mosquito control agent, offering an eco-friendly alternative to synthetic insecticides.

Abstract Background : The housefly is a significant sanitary pest affecting humans and domesticated animals. The application of synthetic insecticides remains the primary tool for managing housefly population outbreaks. However, insecticide resistance in housefly populations is a known major problem worldwide. Methods : Here, we used two field-collected populations of houseflies (POPUFLA and POPNEP) to assess the susceptibility of adults, larvae, and pupae stages to ten commercial formulations of insecticidal products. Then, we investigated the potential biochemical mechanisms underlying their differential susceptibilities using three detoxification enzyme inhibitors. Thereafter, we investigated fitness costs associated with such different susceptibilities to insecticides by constructing age-stage, two-sex, and fertility life tables. Results : Different toxicities of the tested insecticide formulations were found for larvae, pupae, and adult stages. Specifically, susceptibility levels to four insecticides (deltamethrin, lambda-cyhalothrin, thiamethoxam, and a mixture of thiamethoxam with lambda-cyhalothrin), representing two classes of insecticides (pyrethroids and neonicotinoids), varied between the two populations, suggesting resistance occurrence in POPNEP. Furthermore, near complete suppression of lambda-cyhalothrin resistance by piperonyl butoxide (PBO) suggested a CYP-mediated resistance; enhanced CYP and esterases activity is likely the main biochemical mechanism behind resistance to deltamethrin and the mixture of thiamethoxam with lambda-cyhalothrin, while partial reduction in resistance with PBO and diethyl maleate, and triphenyl phosphate implies that multiple mechanisms are responsible for resistance to thiamethoxam. Moreover, the analysis of different life-history traits, using an age-stage, two-sex, and fertility life tables, showed that none of the development, reproduction, and population parameters were affected, indicating that under laboratory conditions, no major fitness costs were found to be associated with the observed resistance. Conclusions : A better understanding of the resistance-related fitness cost can further improve resistance control strategies for M. domestica .

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the major pests infesting squash (Cucurbita spp.). The present study examined the interactions between combined applications of 2 insecticides, imidacloprid and cyantraniliprole, with 2 entomopathogenic fungi (EPF), Beauveria bassiana (GHA strain) and Cordyceps javanica (wfGA17 strain), across 8 squash cultivars infested with B. tabaci. The insecticides were tested for compatibility with EPF at three concentrations using in vitro bioassays. A compatible rate based on the survival of the EPF was subsequently selected for evaluating the lethality against B. tabaci. The combined application of EPF and either of the insecticides resulted in higher B. tabaci nymphal mortality than when either agent was applied alone. Although some reduction in fungal viability was observed, some combinations still produced enhanced efficacy, particularly with imidacloprid. Among all treatments, the combinations involving imidacloprid yielded the highest percentage mortality. The nature of EPF-chemical interactions (synergy, additivity, or antagonism) varied by cultivar. Additive interactions were consistently recorded on the cultivars Early Summer, Fortune, Gray Summer, and Green Eclipse where both EPF species showed enhanced effectiveness when combined with imidacloprid, and to a similar extent, with cyantraniliprole. However, antagonistic interactions were found when C. javanica was combined with cyantraniliprole on the cultivars, Gentry, Grey Summer, Lioness, and Respect, or B. bassiana and imidacloprid on the cultivar Golden glory. Overall, the results emphasized the potential of combining EPF with selective insecticides and the importance of cultivar-specific responses in optimizing B. tabaci control.

Groundnut (Arachis hypogaea L.) is a major oilseed crop globally, but its productivity is severely affected by polyphagous pests such as Spodoptera litura Fab. and Helicoverpa armigera Hub. (Lepidoptera: Noctuidae). These lepidopteran pests cause significant damage to foliage, resulting in yield losses. Silicon (Si), an abundant element in the Earth's crust, is increasingly recognized for its role in enhancing plant resistance to biotic stress. This study aimed to evaluate the impact of calcium silicate supplementation on the developmental biology and nutritional physiology of S. litura and H. armigera larvae feeding on groundnut leaves. Groundnut plants were treated with calcium silicate via foliar spray (2.0%, 3.5%, 5.0%), soil drenching (10%, 15%, 20%) and combined applications. Larval and pupal durations were significantly prolonged under combined treatments (e.g. S. litura larval period: 17.81 days versus 16.13 days in control; pupal period: 11.62 versus 10.36 days). Nutritional indices declined markedly: efficiency of conversion of ingested food (ECI) in H. armigera decreased from 18.65% (control) to 15.31% (treated), and efficiency of conversion of digested food (ECD) in S. litura dropped from 18.14% to 14.02%. Relative consumption and growth rates also were reduced, indicating impaired feeding and growth performance. Calcium silicate application, particularly through combined foliar and soil treatments, negatively influenced larval development and food utilization in S. litura and H. armigera. These findings highlight silicon's potential as an ecofriendly component of integrated pest management strategies in groundnut cultivation, offering a sustainable alternative to synthetic insecticides. © 2026 Society of Chemical Industry.

The Asian citrus psyllid, Diaphorina citri, vectors Candidatus Liberibacter asiaticus (CLas) that causes citrus greening disease, which has devastated global citrus production. Current management primarily relies on the application of synthetic chemical insecticides, resulting in the evolution of resistance among D. citri populations. CLas is ingested by D. citri while feeding on infected plants and subsequently interacts with the gut epithelial surface to establish infection. To determine the functional significance of abundant gut surface proteins in D. citri during CLas uptake, we used RNA interference (RNAi) to silence nine key gut surface protein genes. Following membrane feeding on double-stranded RNAs (dsRNAs), transcript levels were reduced by 20-51% in adults and 28-50% in nymphs at 72 h, with higher knockdown efficiencies of 41-63% in adults and 30-81% in nymphs by 120 h. Some dsRNA treatments increased D. citri mortality by approximately 20% over the control treatment, and two treatments reduced honeydew production indicative of reduced feeding consistent with disrupted gut function. Silencing of several individual proteins, including alkaline phosphatase, cadherin, cluster of calcium-transporting ATPase, croquemort and monocarboxylate transporter, reduced CLas uptake in nymphs and/or adults. Silencing of abundant gut surface proteins in D. citri limited CLas uptake, establishing a functional basis for RNAi-mediated suppression of pathogen uptake. While additional studies are needed to determine specific molecular interactions, these results identify gut surface proteins as promising targets for RNAi-based interventions to reduce CLas uptake by psyllids. © 2026 Society of Chemical Industry.

Bio-Elicitors Could Perform Better Over Synthetic Insecticides in Promoting Plant Growth, Nutrient Acquisition, and Aphid Resistance in Canola Through Phenolic Enhancement

This study aimed to evaluate the effectiveness of a sustainable pest management program for controlling the coffee berry borer (CBB), Hypothenemus hampei, at La Catalina coffee farm (Pereira, Risaralda, Colombia) and compare it with the historical conventional control approach (2012-2022), a period during which the management of CBB was based primarily on the application of synthetic chemical insecticides. The working hypothesis was that integrating biological control agents (Phymastichus coffea, Prorops nasuta, and Beauveria bassiana) with cultural and monitoring practices would significantly reduce infestation levels and insecticide dependence while maintaining or improving economic profitability. From 2023 to 2024, GIS-based hotspot mapping, targeted parasitoid release, and fungal application triggered when infestation thresholds were reached were incorporated into sustainable pest management. Infestation, flight activity, and parasitism rates were monitored, and climatic variables were analyzed to determine their relationships with pest dynamics. The results showed that a sustainable pest management program reduced field infestation from a historical average of 3.3 ± 0.15% to 1.7 ± 0.2%, remaining below the 2% action threshold (F-test, p < 0.05). Prorops nasuta reduced the number of CBB life stages by 32.1%, falling from 10.9 ± 0.3 individuals per berry in non-parasitized fruits to 7.0 ± 0.7 in parasitized berries, while parasitism by P. coffea peaked at 70%. CBB flight activity decreased markedly compared to historical averages. The shift from a chemical approach to sustainable pest management resulted in a 26% increase in net income per hectare and a Marginal Rate of Return (MRR) of 18.06. Overall, the results confirm that a sustainable pest management program effectively suppresses CBB populations, minimizes pesticide use, and enhances the economic and environmental sustainability of coffee production systems.

The diamond back moth, Plutella xylostella (Linneaus), is a serious pest of cruciferous crops and is notorious for its rapid development of resistance to conventional insecticides. The present study evaluated the antifeedant, larvicidal and developmental inhibitory effects of sweet flag, Acorus calamus Linneaus methanolic extract and its green-synthesized silver nanoparticles (AgNPs) against third instar larvae of P. xylostella. The methanolic extract exhibited strong dose-dependent bioactivity with low AI50 (0.053%),LC50 (0.031%) and I50 (0.024%) values. The biosynthesized AgNPs, confirmed by UV–Vis spectroscopy(SPR peak at 420 nm), DLS (30–80 nm), zeta potential analysis (–35 mV), FE-SEM (spherical morphology)validating successful nanoparticle fabrication showed enhanced insecticidal efficacy, recording completelarval mortality and total suppression of adult emergence at lower concentrations, with AI50, LC50 and I50 values of 6.877, 9.974 and 54.183 ppm, respectively. The results indicate that both A. calamus extract and its nano formulation possess strong insecticidal potential and may serve as eco-friendly alternatives to synthetic insecticides for the management of P. xylostella.