Search Results (46)

The use of chemical pesticides in agriculture has led to the development of resistant pest populations, posing a challenge to long-term pest management. This review aims to evaluate the scientific literature on the individual and combined use of baculoviruses with conventional chemical and biological insecticides to combat Plutella xylostella, Spodoptera exigua, and Spodoptera frugiperda in broccoli, tomato, and maize crops. Notable findings include that both individual Plutella xylostella nucleopolyhedrovirus (PxNPV) and the combination of Plutella xylostella granulovirus (PxGV) and azadirachtin at a low dose effectively control Plutella xylostella; both combinations of Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) with emamectin benzoate and chlorfenapyr reduced resistance in Spodoptera exigua and increased the efficacy of the insecticides; and the combination of Spodoptera frugiperda nucleopolyhedrovirus (SfMNPV) and spinetoram is effective against Spodoptera frugiperda. Integrating baculoviruses into pest management strategies offers a promising approach to mitigate the adverse effects of chemical pesticides, such as resistance development, health risks, and environmental damage. However, there remains a broad spectrum of research opportunities regarding the use of baculoviruses in agriculture. Full article

Thrips parvispinus (Karny) is an invasive pest of vegetable and ornamentals in the United States. To support ornamental growers to control T. parvispinus infestations, we tested seven conventional (spinosad, chlorfenapyr, sulfoxaflor–spinetoram, pyridalyl, tolfenpyrad, abamectin, and cyclaniliprole–flonicamid) and two biorational insecticides (mineral oil and sesame oil) under greenhouse conditions on mandevilla (Mandevilla splendens) and gardenia (Gardenia jasminoides), primary T. parvispinus ornamental hosts. Two insecticide applications were performed: a curative, treating an existing infestation, and a prophylactic, treating a plant prior to the thrips release. In the curative application, ten larvae and ten adults were released two weeks prior to treatment. Three leaves from the upper, middle, and lower canopy were collected 24 h, 7-, and 14-days post-treatment to assess thrips mortality. In the prophylactic application, plants were first sprayed with insecticides, and thrips were introduced 24 h later, but followed the same sampling method. In mandevilla, chlorfenapyr, abamectin, and spinosad caused the highest thrips mortality in both application types. Among horticultural oils, mineral oil and sesame oil increased mortality in prophylactic applications only. In gardenia, neither curative nor prophylactic applications of these products led to significant thrips mortality, and the possible reasons and recommendations for best thrips management are presented. Full article

Background: Long-lasting insecticidal nets (LLINs) have significantly reduced the malaria burden in recent decades, and this malaria prevalence reduction has been achieved through the upgrading of pyrethroid long-lasting insecticidal nets. However, this reduction has stalled due to many factors, including rapidly developing pyrethroid resistance. Method: The protocol was registered in PROSPERO, and we used Cochrane methodology to assess bias and evidence quality. Three reviewers extracted data from individual studies, and a meta-analysis was performed using Excel and STATA version 17, expressing the data as a risk ratio. Result: A study involving 21,916 households from 11 randomized controlled trials showed that the chlorfenapyr treatment group had a 10% reduction in malaria infection risk, with a pooled overall prevalence of 25.96 per 100 children in the chlorfenapyr group and 32.38 per 100 children in the piperonyl butoxide group, compared to 41.60 per 100 children in the control (pyrethroid-only) group. This meta-analysis determined that the entomological outcomes of effectiveness and efficacy showed that these treatments effectively reduced vector density per household per night and mean inoculation rates, with a 23% reduction in chlorfenapyr, a 7% reduction in pyrethroid-only treatments, and a 12% reduction in piperonyl-butoxide-treated groups. This study shows that chlorfenapyr (CFP) and pyriproxyfen (PPF) LLINs are highly effective and more efficacious in reducing malaria infection, case incidence, and anemia among children, as well as in reducing mean indoor vector density, mean entomological inoculation rate, and sporozoite rate, compared to pyriproxyfen (PPF) LLINs in Africa. Conclusions: This study found that chlorfenapyr (CFP) LLINs are highly effective and more efficacious in reducing malaria infection, case incidence, and anemia among children in Africa. Therefore, policymakers and health planners should place strong emphasis on addressing the effectiveness, efficacy, and resistance management of LLINs as part of their current public health agenda to eliminate malaria. Full article

Chlorfenapyr is a widely used insecticide known to harm non-target insects, but its effects on reproductive development in the silkworm (Bombyx mori L.) remain incompletely understood. In this study, we investigated the histopathological and transcriptional changes in the gonads (ovaries and testes) of newly molted fifth-instar silkworm larvae exposed to chlorfenapyr. Histopathological analysis revealed delayed gonadal development, a reduction in oogonia and oocytes in the ovaries, and decreased numbers of spermatocytes in the testes. Transcriptome analysis identified significant differentially expressed genes (DEGs), mainly enriched in pathways such as “Drug metabolism—cytochrome P450”, “Insect hormone biosynthesis”, and “Ribosome”. Key up-regulated genes included members of the cytochrome P450 family (CYP6B5, CYP9f2, CYP6B6), glutathione S-transferases (GSTT1, GST1), and juvenile hormone-related enzymes (JHAMT, JHEH), indicating active detoxification and hormonal regulation responses. Several transcription factor families, particularly C2H2, HB-other, and TRAF, exhibited altered expression, suggesting roles in stress adaptation. Protein–protein interaction (PPI) network analysis identified hub genes such as EcR, Kr-h1, and various ribosomal proteins, highlighting their potential involvement in reproductive development. Quantitative PCR (qPCR) validated the transcriptomic data, confirming the reliability of the results. Overall, these findings enhance our understanding of chlorfenapyr’s impact on silkworm reproductive development and the underlying molecular mechanisms, providing valuable insights for sustainable pest management and ecological risk assessment of insecticides. Full article

We first measured the content of chlorfenapyr and tralopyril in silkworm larvae using HPLC, revealing that chlorfenapyr can be biotransformed into tralopyril in silkworms. Then, a differential transcriptomic database of small RNA was constructed through Illumina RNA-Sequencing. qRT-PCR was conducted to determine the expression levels of Bmo-miR-6497-5p and the target CYP450 gene, and Bmo-miR-6497-5p was significantly upregulated in the L3 silkworm larvae 24, 48, and 72 h after they were treated with chlorfenapyr. Furthermore, the target P450 gene CYP337A2 was downregulated at these time points. Dual-luciferase validation revealed that the luciferase activity significantly decreased after Bmo-miR-6497-5p bound to CYP337A2. In addition, miRNA mimics/inhibitor injection and bioassays of chlorfenapyr and tralopyril revealed that the mortality of third silkworm larvae injected with the antagomir of Bmo-miR-6497-5p was significantly increased after exposure to a sublethal concentration of chlorfenapyr. These results imply that Bmo-miR-6497-5p targets CYP337A2, regulating its expression. Also, silkworms increase their tolerance to chlorfenapyr by upregulating Bmo-miR-6497-5p expression, thereby inhibiting the biotransformation of chlorfenapyr to toxic tralopyril catalyzed by CYP337A2. The present study reveals the function of microRNA in silkworm tolerance to chlorfenapyr and improves understanding regarding insecticide resistance in Lepidopteran insects. Full article

Isocycloseram is a novel insecticide belonging to the class of isoxazoline (IRAC MoA Group 30) that exhibits excellent efficacy and selectivity against invertebrate pests. We evaluated the efficacy of two 0.1% isocycloseram formulations against a laboratory and four insecticide-resistant field strains of common bed bugs (Cimex lectularius L.) (Hemiptera: Cimicidae) by direct spray and forced exposure on three surfaces (fabric, vinyl tiles, and unpainted pinewood). Their efficacy was compared with that of five commercial insecticides including Demand CS (0.03% λ-cyhalothrin), Temprid FX (0.05% imidacloprid and 0.025% β-cyfluthrin), Crossfire (0.4% clothianidin, 0.01% metofluthrin, and 1.0% piperonyl butoxide), Bedlam Plus (0.4% d-phenothrin, 1.0% MGK 264, and 0.05% imidacloprid), and PT Phantom II (0.5% chlorfenapyr). Both isocycloseram 45 SC and 400 SC formulations were the most effective among the tested insecticides. The isocycloseram 45 SC formulation caused faster mortality than the 400 SC formulation. Four hours of exposure to 0.025, 0.05, and 0.1% isocycloseram 45 SC residue on porous and non-porous surfaces caused 100% bed bug mortality after 3–4 days. Exposure to 30-day-aged 0.1% isocycloseram 45 SC residue for 4 h still caused 100% mortality, compared to 0–73% mortality by the five commercial insecticides. Isocycloseram is a highly effective compound for controlling resistant C. lectularius populations. Full article

Entomopathogenic fungi represent a valuable natural resource with significant potential as biological agents for pest management. However, different species or strains of fungi demonstrate varying effectiveness against specific targets. In this study, we assessed the impact of two fungal strains, Beauveria bassiana KN801 and KN802, on the rice planthoppers Ninaparvata lugens and Sogatella furcifera, in combination with insecticides. Our findings indicate that both B. bassiana strains can effectively infect the nymphs and adults of N. lugens and S. furcifera, resulting in a significantly higher mortality rate compared to the control groups. Notably, the B. bassiana strain KN801 demonstrated greater virulence than B. bassiana KN802 against these pests. However, no significant differences were observed when using different concentrations of the same fungal strain (B. bassiana KN801 or B. bassiana KN802) against these targets. Additionally, both fungi showed a germination rate of over 90% after treatment when combined with several common insecticides like chlorfenapyr and dinotefuran. The combined application of B. bassiana with chlorfenapyr or dinotefuran could improve pest control efficacy for these two pests. This study suggests that the two B. bassiana strains have the potential to infect rice planthoppers N. lugens and S. furcifera, indicating their promise as agents for the control of these pests. Full article

Residues of the pesticides chlorfenapyr (CFP) and emamectin benzoate (EMB) often coexist in the environment and can be accumulated in the body. To understand the impact of these two chemicals on health, we investigated their effect on the kidneys. In this study, rats were treated with CFP and/or EMB at low/medium/high doses of 1/3/9 mg/kg/day and 0.2/0.6/1.8 mg/kg/day, respectively, via oral gavage for 60 days. Kidneys and serum samples were collected and serum biochemistry and kidney histopathological changes were analyzed and examined. Kidney metabolome alterations were analyzed by using gas chromatography–mass spectrometry. The results showed that combined exposure to CFP and EMB elevated BUN levels and induced pathological damage, which presented as thinner renal tubular epithelial cells, an abnormal glomerular morphology, and an increased fibrotic area. CFP and/or EMB disrupted glutathione metabolism and carbohydrate metabolism, resulting in the alteration of kidney metabolomes and inducing oxidative stress in the cells of kidney tissues. In addition, CFP decreased ATP content and inhibited pyruvate PDH activity in the kidneys. These findings suggest that long-term exposure to CFP and EMB at environmentally relevant levels induce alterations in the renal metabolome, oxidative stress, and an insufficient energy supply, which may contribute to renal histopathological damage. Full article

The objective of this study was to identify the Hsp70s in Paracoccus marginatus and explore their roles in P. marginatus’s resistance to temperature and insecticide stress. The full-length cDNA sequences of PmHsp70s were obtained by PCR cloning and sequencing. The physicochemical and structural characteristics of PmHsp70s were analyzed, and a phylogenetic tree was constructed. The gene expressions of PmHsp70s were detected using qRT-PCR to explore the impacts of temperature and insecticide stress on P. marginatus. A total of 12 PmHsp70s were identified and cloned. The amino acids encoded by PmHsp70s were found to contain highly conserved regions characteristic of the Hsp70 family. The subcellular localization results showed that the majority of PmHsp70s were located in the cytoplasm. A total of 13 unique conserved motifs were identified for the PmHsp70s, of which 9 were shared motifs. The phylogenetic tree showed that the 12 PmHsp70s could be clustered into five branches, with the closest evolutionary relationship observed with the Phenacoccus solenopsis. The expression of the majority of PmHsp70s was up-regulated in P. marginatus when subjected to heat stress, with the higher expression fold change observed for PmHsp70-9, PmHsp70-11, and PmHsp70-12. The expression of specific PmHsp70s was notably suppressed under cold stress, whereas the expression of others was markedly enhanced. Upon exposure to chlorfenapyr and lambda-cyhalothrin, the expressions of PmHsp70-11 and PmHsp70-12 were significantly up-regulated with the highest expression fold change, respectively. The results revealed the significance of specific PmHsp70s in the resistance of P. marginatus to temperature and insecticide stress. This study improved our understanding of the mechanisms underlying P. marginatus’s adaptive responses to unfavorable environmental conditions. Full article

Insecticides are widely used to boost crop yields, but their effects on non-target insects like Vespa magnifica are still poorly understood. Despite its ecological and economic significance, Vespa magnifica has been largely neglected in risk assessments. This study employed physiological, biochemical, and transcriptomic analyses to investigate the impact of sublethal concentrations of thiamethoxam, avermectin, chlorfenapyr, and β-cypermethrin on Vespa magnifica. Although larval survival rates remained unchanged, both pupation and fledge rates were significantly reduced. Enzymatic assays indicated an upregulation of superoxide dismutase and catalase activity alongside a suppression of peroxidase under insecticide stress. Transcriptomic analysis revealed increased adenosine triphosphate-related processes and mitochondrial electron transport activity, suggesting elevated energy expenditure to counter insecticide exposure, potentially impairing essential functions like flight, hunting, and immune response. The enrichment of pathways such as glycolysis, hypoxia-inducible factor signaling, and cholinergic synaptic metabolism under insecticide stress highlights the complexity of the molecular response with notable effects on learning, memory, and detoxification processes. These findings underscore the broader ecological risks of insecticide exposure to non-target insects and highlight the need for further research into the long-term effects of newer insecticides along with the development of strategies to safeguard beneficial insect populations. Full article

The versatility of cytochrome P450 reductase (CPR) in transferring electrons to P450s from other closely related species has been extensively exploited, e.g., by using An. gambiae CPR (AgCPR), as a homologous surrogate, to validate the role of An. funestus P450s in insecticide resistance. However, genomic variation between the AgCPR and An. funestus CPR (AfCPR) suggests that the full metabolism spectrum of An. funestus P450s might be missed when using AgCPR. To test this hypothesis, we expressed AgCPR and AfCPR side-by-side with CYP6P9a and CYP6P9b and functionally validated their role in the detoxification of insecticides from five different classes. Major variations were observed within the FAD- and NADP-binding domains of AgCPR and AfCPR, e.g., the coordinates of the second FAD stacking residue AfCPR-Y⁴⁵⁶ differ from that of AgCPR-His⁴⁵⁶. While no significant differences were observed in the cytochrome c reductase activities, when co-expressed with their endogenous AfCPR, the P450s significantly metabolized higher amounts of permethrin and deltamethrin, with CYP6P9b-AfCPR membrane metabolizing α-cypermethrin as well. Only the CYP6P9a-AfCPR membrane significantly metabolized DDT (producing dicofol), bendiocarb, clothianidin, and chlorfenapyr (bioactivation into tralopyril). This demonstrates the broad substrate specificity of An. funestus CYP6P9a/-b, capturing their role in conferring cross-resistance towards unrelated insecticide classes, which can complicate resistance management. Full article

Repeated pesticide residue detection in chili peppers in the Republic of Korea has become a serious health concern. Thus, monitoring domestically grown and imported chili peppers for pesticide residues is of great significance. Here, we investigated pesticide residues detected in imported and domestically grown chili peppers using global pesticide residue monitoring data. Our analysis involved organizing inspection and detection data from different sources. Global pesticide residue monitoring data for chili peppers revealed 139 pesticide types, 43,532 inspections, and 3966 detections (detection rate, 9.11%). Peppers from Mexico were sampled the most (39,927 inspections) and showed the highest number of detected cases (2998 cases). Globally, the top 10 most frequently detected pesticides were clothianidin, imidacloprid, thiamethoxam, chlorpyrifos, thiacloprid, metalaxyl, myclobutanil, azoxystrobin, carbendazim, and cyhalothrin, with detection rates in the range of 10.52–28.66%. Furthermore, domestic chili pepper pesticide residue monitoring revealed 73 pesticide types, 3535 inspections, and 332 detected cases (detection rate, 9.39%), and the top 10 most frequently detected pesticides were chlorfenapyr, tebuconazole, flonicamid, dinotefuran, boscalid, pyraclostrobin, fluxametamide, thiamethoxam, pyridaben, and azoxystrobin, with detection rates in the range of 13.89–32.58%. These findings may serve as fundamental data for safety management related to chili pepper pesticide residues in the Republic of Korea. Full article

The house fly Musca domestica L. is one of the most common insects of veterinary and medical importance worldwide; its ability to develop resistance to a large number of insecticides is well known. Many studies support the involvement of cytochrome P-450-dependent monooxygenases (P450) in the development of resistance to pyrethroids, neonicotinoids, carbamates, and organophosphates among insects. In this paper, the monooxygenase activity and expression level of CYP6D1 were studied for the first time in a chlorfenapyr-resistant strain of house fly. Our studies demonstrated that P450 activity in adults of the susceptible strain (Lab TY) and chlorfenapyr-resistant strain (ChlA) was 1.56–4.05-fold higher than that in larvae. In females of the Lab TY and ChlA strains, this activity was 1.53- and 1.57-fold higher, respectively (p < 0.05), than that in males, and in contrast, the expression level of CYP6D1 was 21- and 8-fold lower, respectively. The monooxygenase activity did not vary between larvae of the susceptible strain Lab TY and the chlorfenapyr-resistant strain ChlA. Activity in females and males of the ChlA strain exceeded that in the Lab TY strain specimens by 1.54 (p = 0.08) and 1.83 (p < 0.05) times, respectively, with the same level of CYP6D1 expression. PCR-RFLP analysis revealed a previously undescribed mutation in the promoter region of the CYP6D1 gene in adults of the Lab TY and ChlA strains, and it did not affect the gene expression level. The obtained results show that the development of resistance to chlorfenapyr in M. domestica is accompanied by an increase in P450-monooxygenase activity without changes in CYP6D1 expression. Full article

Tetranychus urticae Koch, a phytophagous mite, is one of the most significant crop pests globally. The primary method employed for controlling T. urticae involves chemical means, utilizing synthesized products, posing the risk of developing resistance. The urgency for novel strategies integrated into pest management programs to combat this mite is becoming increasingly imperative. Botanical pesticides emerge as a promising tool to forestall arthropod resistance. Among these, extracts from Rutaceae plants, abundant in bioactive specialized metabolites, have demonstrated potential as insecticides and miticides. In this study, various concentrations of alkaloidal extracts sourced from the bark of Zanthoxylum schreberi J.F.Gmel. (Rutaceae) were evaluated against T. urticae adult females. Furthermore, the extract’s combination with three distinct commercial acaricides (i.e., chlorfenapyr, cyflumetofen, and abamectin) was also assessed for this mite. Chemical characterization of the extract via LC-MS allowed for the annotation of various compounds related to ten benzylisoquinoline-derived alkaloids. The extract, both alone and in combination with commercial insecticides, yielded varying responses, inducing over 40% mortality at 2% w/w, demonstrating a 90% repellency rate at the same concentration, and exerting a moderate impact on fecundity. These treatments extended beyond phenotypic responses, delving into the biochemical effects on treated T. urticae females through an exploration of the impact on four enzymes, i.e., acetylcholinesterase (AChE), glutathione S-transferase (GST), esterases (GE), and P450-like monooxygenases (PMO). Employing consensus docking studies and in vitro enzymatic evaluations, it was discovered that the Z. schreberi-derived extract and its constituents significantly affected two key enzymes, AChE and GST (IC₅₀ < 6 µM), which were associated with the phenotypic observations of T. urticae females. The evaluation of alkaloid-rich botanicals showcases promising potential as a relevant biotechnological strategy in addressing mite-related concerns, offering a pathway toward innovative and sustainable pest management solutions. Full article

Pyrethroid-treated long-lasting insecticidal nets (LLINs) have been the main contributor to the reduction in malaria in the past two decades in sub-Saharan Africa. The development of pyrethroid insecticide resistance threatens the future of LLINs, especially when nets become holed and pyrethroid decays. In this study, three new classes of dual-active ingredient (AI) LLINs were evaluated for their physical durability: (1) Royal Guard, combining pyriproxyfen, which disrupts female fertility, and a pyrethroid, alpha-cypermethrin; (2) Interceptor G2, which combines the pyrrole chlorfenapyr and a pyrethroid (alpha-cypermethrin); (3) Olyset Plus, which incorporates the pyrethroid permethrin and the synergist piperonyl butoxide, to enhance the pyrethroid potency; and Interceptor, a reference net that contains alpha-cypermethrin as the sole active ingredient. About 40,000 nets of each type were distributed in February 2019 to different villages in Misungwi. A total of 3072 LLINs were followed up every 6–12 months up to 36 months to assess survivorship and fabric integrity. The median functional survival was less than three years with Interceptor, Interceptor G2, and Royal Guard showing 1.9 years each and Olyset Plus showing 0.9 years. After 36 months, 90% of Olyset Plus and Royal Guard and 87% of Interceptor G2 were no longer in use (discarded) due to wear and tear, compared to 79% for Interceptor. All dual-AI LLINs exhibited poor textile durability, with Olyset Plus being the worst. Full article