Tetranychus Urticae Research Articles

Predatory thrips in action: Scolothrips sexmaculatus (Pergande) and Scolothrips tenuipennis zur Strassen, 1965 (Thripidae) feeding on Tetranychus urticae (Acari) in Brazil

The purpose of this study is to report the presence in Brazil of two predatory thrips species feeding on mites in commercial hop plantations (Humulus lupulus, Cannabaceae). The mite, Tetranychus urticae Koch, is known as the two-spotted spider mite (TSSM) and is a major pest in several crops, including hop, threatening yields by damaging leaf tissues and, in severe cases, covering foliage with webs. It is native to Eurasia but is now present globally, with a wide range of natural enemies, including commercially used biological controls such as Stethorus beetles and phytoseiid mites (Sirrine et al. 2010; Turner et al. 2011).

SYNCAS based CRISPR-Cas9 editing in predatory mites, whiteflies and stinkbugs

Despite the establishment of CRISPR-Cas9 gene editing protocols in a wide range of organisms, genetic engineering is still challenging for many organisms due to constraints including lethality of embryo injection, difficulties in egg/embryo collection or viviparous lifestyles. Recently, an efficient CRISPR-Cas9 method, termed SYNCAS, was developed to genetically modify spider mites and thrips species. The method is based on maternal injection of formulated CRISPR-Cas9 using saponin and BAPC. Here, we investigate whether the method can be used to perform gene editing in other arthropods such as the beneficial predatory mites Amblyseius swirskii and Phytoseiulus persimilis, and the pests Bemisia tabaci and Nezara viridula. For the predatory mites, Antp and SLC25A38 were used as target genes, while the ortholog of the Drosophila melanogaster ABCG transporter white was targeted in B. tabaci and N. viridula. All species were successfully edited with the highest efficiencies (up to 39%) being obtained for B. tabaci. For A. swirskii and P. persimilis no clear phenotypes could be observed, even though SLC25A38 was successfully knocked-out. The lack of a color phenotype in SLC25A38 mutants was confirmed in the spider mite Tetranychus urticae. Disruption of the target gene Antp is likely lethal in predatory mites, as no true null mutants could be recovered. For B. tabaci, KO of white resulted in orange eyes which diverges from the phenotype seen in white mutants of D. melanogaster. In the last species, N. viridula, a single phenotypic mutant could be detected having a patchy white body coloration with wild type eye coloration. Genotyping revealed a single amino acid deletion at the target site, suggesting the creation of a hypomorphic allele. To conclude, the protocols provided in this work can contribute to the genetic study of predatory mites used in biological control, as well as hemipteran pests.

Target gene selection for sprayable dsRNA-based biopesticide against Tetranychus urticae Koch (Acari: Tetranychidae).

Because of the excessive use of synthetic chemicals, the two-spotted spider mite, Tetranychus urticae Koch, a highly polyphagous pest, has developed comprehensive resistance to a broad spectrum of pesticides with diverse modes of action, raising severe concerns over agroecosystems and human health. To resolve this emerging issue, we initiated a project to develop double-stranded RNA (dsRNA)-based biopesticides against T. urticae, aiming for a species-specific and sustainable pest management alternative. To examine the uptake of dsRNAs using the egg-soaking delivery method, we fluorescently labeled extraneous dsRNAs, and later showed that T. urticae dsRNAs can permeate through eggshell in a time-dependent manner within the first 24 h. For target gene screening, silencing of Prosbeta-1 and -5 resulted in the highest mortality (>90%) and a dark body phenotype in T. urticae. Notably, each target gene was effective in both avermectin laboratory susceptible and field resistant populations. As such, Prosbeta-5 was selected as the candidate target gene for subsequent spray-induced gene silencing (SIGS). After two rounds of spray at day 5 and day 12, SIGS led to a substantial suppression of T. urticae populations (>90%). Our combined results suggest viable molecular targets, confirm the feasibility of SIGS against T. urticae, and lay the foundation for the development of dsRNA-based biopesticides to control this devastating pest. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Plant Oil Nano-Emulsions as a Potential Solution for Pest Control in Sustainable Agriculture

The increasing demand for sustainable and eco-friendly pest control methods has led to a growing interest in the development of novel, plant-based pesticides. In this study, we investigated the potential of nano-emulsions containing plant oils (Portulaca oleracea, Raphanus sativus, and Rosmarinus officinalis) as a new approach for controlling three major pests: Aphis gossypii, Spodoptera littoralis, and Tetranychus urticae. Using ultrasonication, we prepared stable and uniform nano-emulsions characterized by thermodynamic properties, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The results showed that the nano-emulsions were effective in controlling the three pests, with the most potent activity observed against Aphis gossypii. Our findings suggest that plant oil nano-emulsions have the potential to be used as a sustainable and eco-friendly alternative to traditional pesticides. The use of these nano-emulsions could provide a new approach to manage pest populations, reducing the environmental impact of pesticide use, and promoting sustainable agriculture.

Formulation of Ethyl Cellulose Nanoparticles Encapsulated with Osthole Provides Long-Lasting Plant Protection against a Major Pest Mite.

The broader use of botanical pesticides has been limited by shorter residual activity on plants, slower onset of action, and higher costs compared with conventional pesticides. These challenges could be overcome by the development of simple, cost-effective, and long-lasting preventive nanocomposites for botanical pesticides. In this study, we successfully developed a low-cost ethyl cellulose (EC)-based delivery system for the botanical pesticide osthole (OST), designed to provide extended preventive protection against Tetranychus urticae infestations. A comparative analysis of the three nanocomposites (graphene oxide (GO)-OST, EC-OST, and chitosan (CS)-OST) revealed that EC-OST exhibited superior thermal stability, UV resistance, controlled release of the OST payload, and strong acaricidal activity. The degradation of OST on leaf surfaces was reduced by encapsulation in EC, while its penetration into plant tissues was improved. When EC-OST was applied to leaves, an increase in T. urticae mortality, a reduction in reproduction and egg adhesion, and impairment of feeding behavior through extended searching and feeding times were observed. The peak occurrence of T. urticae infestation was delayed by 10 days following the preventive application of EC-OST, reducing plant damage and protecting the plants for more than 20 days. This nanoinsecticide allows for low-frequency OST application, reducing farmers' production costs, and increasing profitability, thereby offering great potential for promoting the use of botanical pesticides in plant protection.

Quercetin, a natural flavonoid induced by the spider mite Tetranychus urticae or alamethicin, is involved in the defense of lima bean against spider mites.

Phaseolus lunatus, commonly known as the lima bean, is a leguminous crop cultivated in various regions worldwide. It is native to tropical America and is extensively grown in both tropical and temperate climates. Lima beans are highly nutritious and versatile, serving not only as a food and vegetable, but also as a source of green manure. During cultivation, lima beans can be vulnerable to numerous pests, including the spider mite, Tetranychus urticae. In large-scale outbreaks, T. urticae can cause significant yield losses or even crop failure, posing a serious threat to agricultural production. The treatment of lima bean plants with T. urticae or alamethicin (ALA) has been shown to enhance their insect-resistant defense responses. Understanding the transcriptional and metabolic mechanisms underlying these defense responses to T. urticae and ALA is crucial for improving herbivore resistance in lima bean crops. By integrated analysis of transcriptomics and metabolomics data, we found that both T. urticae and ALA treatments significantly induced the flavonoid biosynthesis pathway. Both treatments increased the flavonoid content in lima bean leaves by upregulating the expression of key genes in this pathway, potentially contributing to enhanced resistance to phytophagous insects. Notably, quercetin has been shown to reduce the number of eggs per female and survival rate of T. urticae. These findings provide a novel theoretical basis for understanding the response mechanisms of lima beans to T. urticae and ALA, while highlighting potential metabolites and genes that could be targeted to improve plant resistance to spider mite damage. © 2025 Society of Chemical Industry.

Identification of Mango Cultivars’ Resistance Against Red Spider Mite: Impact of Climate Elements on Resistance Performance

The use of resistant plants is recognized as an environmentally friendly measure for mite control. Oligonychus mangiferus, known as the mango red spider mite (MRSM), is a dangerous pest for mango production. To date, the resistance levels of the mango germplasms against the MRSM remain largely unknown. Furthermore, the environmental factors potentially influencing resistance performance have been seldom discussed. To fill those knowledge gaps, this study aimed to identify the resistance level of twelve mango cultivars against the MRSM. Based on three rounds of greenhouse and five seasons of field tests, cultivars with distinct resistant levels were identified. When exploring the climate impact, we found that for the susceptible cultivars, precipitation is the primary external environment factor altering the resistance performance, while temperature presents a secondary effect, and air humidity did not show a significant impact on MRSM resistance. By contrast, MRSM-resistant cultivars were not prone to be affected by changing climate conditions. Furthermore, yield tests indicated that the resistant cultivars can better reduce the yield losses compared with the susceptible ones. This study illustrated the climate element-driven effect on mango tree resistance performance against the MRSM, which can provide insight into insect pest management under changing climate conditions.

Bio Efficacy of Certain Botanical Extracts, Oils and Acaricide Against Two Spotted Spider Mites [Tetranychus urticae (Koch)] on Okra

Field and pot culture experiments were conducted Annamalai University, Tamil Nadu, India during 2012 - 2013 to evaluate the bio efficacy of certain botanical extracts, oils and acaricides against two spotted spider mite (TSSM) Tetranychus urticae (Koch) on okra. Vitex negundo leaf extract, Clerodendron inermea leaf extract, Wedelia chinensis leaf extract, Neem oil, Pungam oil, Pinnai oil, Illupai oil, NSKE, Dicofol and Fenezaquin were used for the study. The maximum mite population was observed in 5% W. chinensis leaf extract (15.08) sprayed plants followed by, 5% C. inermea leaf extract (13.95), 3% illupai oil (11.86) and NSKE 5% (11. 67) respectively. Amoderate mite population was observed in 5% V. negundo leaf extract (10.70), 3% pungam oil (10.05), 3% pinnai oil (9.53) and 3% neem oil (9.05) sprayed plants respectively. Whereas the least mite population was observed in dicofol 0.2% (8.13) and fenezaquin 0.2% (8.01) sprayed okra plants.

Bioinoculant-induced plant resistance is modulated by interactions with resident soil microbes

BackgroundEntomopathogenic fungi are increasingly used as bio-inoculants to enhance crop growth and resistance. When applied to rhizosphere soil, they interact with resident soil microbes, which can affect their ability to colonize and induce resistance in plants as well as modify the structure of the resident soil microbiome, either directly through interactions in the rhizosphere or indirectly, mediated by the plant. The extent to which such direct versus indirect interactions between bio-inoculants and soil microbes impact microbe-induced resistance in crops remains unclear. This study uses a split-root system to examine the effects of direct versus indirect (plant-mediated) interactions between an entomopathogenic fungus, Metarhizium brunneum, and resident soil microbes on induced resistance in tomato against two-spotted spider mites. Additionally, the study explores how these interactions influence the composition and diversity of soil fungal and bacterial communities.ResultsResident soil microbes reduced the efficacy of M. brunneum to induce resistance against spider mites. This reduction occurred not only when resident microbes directly interacted with the bio-inoculant but also when they were spatially separated within the root system, indicating plant-mediated effects. M. brunneum inoculation did not affect rhizosphere microbial diversity but led to changes in fungal and bacterial community composition, even when these communities were not in direct contact with the inoculant.ConclusionsThis research highlights the impact of both direct and plant-mediated interactions between bio-inoculants and resident soil microbes on bio-inoculant-induced pest resistance in crop plants and underscores the importance of assessing potential adverse effects of fungal bio-inoculants on native soil communities.

Behavioral and acaricidal effects of the chlorfenapyr and acequinocyl on the predatory mites, Neoseiulus californicus and Phytoseiulus persimilis (Acari: Phytoseiidae).

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is a major pest of various plants with a worldwide distribution. Extensive use of chemical pesticides has led to the development of resistance in this pest, making biological control agents a viable alternative for its management. The predatory mites, Neoseiulus californicus (McGregor) and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) are the most important predators of the two-spotted spider mites. In this study, the toxicity of two acaricides chlorfenapyr and acequinocyl, on these predators was evaluated, and the walking behavior of predatory mites after exposure to residues of the pesticides was assessed using a video tracking system. Based on the results,the LC50 valuesof both acaricides was estimated to be higher than their field concentration,andchlorfenapyr was found to be five-fold more toxic than acequinocyl. In the behavioral assay, both acaricides significantly affected the distance and speed of walking, resting time, and frequency of stops of both predatory mites. In the escape assay, both compounds had an irritable effect on both predatory mites, as the mites avoided areas contaminated with pesticide residues and their presence in the untreated area was significantly longer than in the treated area (P < 0.05). However, the study found no correlation between toxicity and irritability. According to the results of this study, N. californicus and P. persimilis possess the ability to detect the presence of pesticide residues in their environment and try to avoid them. Moreover, both compounds are at low risk to these mites, but acequinocyl is much safer and is a suitable option for use in integrated pest management.

Behavior of Typhlodromus (Anthoseius) recki confronted to a combination of plants and food: pollen, Tetranychus urticae and Aculops lycopersici for companion plant use.

Typhlodromus (Anthoseius) recki feeds on pest mites on tomato plants and its introduction into crops via companion plants, Mentha suaveolens and Phlomis fruticosa, has been recently investigated. This study aims at assessing the predator arrestment behavior, through lab choice tests to determine the effects of (i) prey (Aculops lycopersici and Tetranychus urticae) vs Typha angustifolia pollen deposited on companion plant or Solanum nigrum, (ii) T. urticae vs A. lycopersici on S. nigrum and (ii) M. suaveolens vs P. fruticosa using pollen as food source. The predator position, the number of eggs laid and the number of T. urticae eggs consumed were assessed during 4 days. The predator was more observed on leaf discs with A. lycopersici vs pollen when the pollen was deposited on S. nigrum and M. suaveolens, but was more found on leaf discs with pollen on P. fruticosa. It was equally found on leaf discs with T. urticae vs pollen for all the plants tested. No difference in predator arrestment behavior was noted between A. lycopersici and T. urticae, but a higher proportion was observed on leaf discs with A. lycopersici at the beginning of the experiment than at the end. Finally, the predator was more observed on leaf discs of P. fruticosa than of M. suaveolens. The highest fecundity was observed in systems with pollen and A. lycopersci + pollen, and the lowest with T. urticae + pollen; T. urticae consumption was not different with pollen or A. lycopersici. The predator less arrested on pollen vs A. lycopersici that provides a high fecundity; however, surprisingly it was more attracted to pollen vs a prey T. urticae, questioning the cues perceived by T. (A.) recki. The strong preference for P. fruticosa without prey vs S. nigrum with prey or M. suaveolens with pollen, suggests for the second time for Phytoseiidae, direct effects of plant (may be via odors) and questions the ecological advantages of such a behavior. For practical issues, M. suaveolens would be a better bank plant than P. fruticosa; an arrestment on patches of A. lycopersici within tomato plant is expected even if pollen is present and in case of T. urticae infestation a low dispersal to this prey will probably occur, questioning the interest to use T. (A.) recki in combination with other Phytoseiidae species, specialized in T. urticae predation, as Phytoseiulus persimilis.

Effects of timed LED regimes on tomato plant traits, performance of two-spotted spider mites, and predatory mites (Phytoseiulus persimilis).

Light-emitting diodes (LEDs) are being used in controlled environments to enhance crop production and pest management with most studies focusing on continuous treatments (applied throughout the entire daytime or nighttime period). Here, we tested the hypothesis that providing tomato plants with timed LED regimes (daily 3-h doses of red, blue, or far-red LED) during the day or at night may affect their traits (leaf reflectance indices, element composition, and phenolic profile), performance of two-spotted spider mites (Tetranychus urticae) (TSSM), and a species of predatory mite (Phytoseiulus persimilis). Nighttime LED regimes significantly altered leaf element composition: red LED increased K levels, blue LED enhanced Mg levels, and far-red LED enhanced Mn and Cu and reduced Zn levels. Among daytime LED regimes, blue LED reduced Zn level. Nighttime LED regimes significantly increased leaf glandular trichome densities (except far-red regime) and reduced total phenolic content. Among a series of leaf reflectance indices, ARI and CRI increased significantly in response to nighttime red and blue regimes but decreased with far-red LED regimes. Performance bioassays showed significantly lower TSSM populations on nighttime plants than on daytime and control plants. LED regimes did not affect predatory mites' population and their feeding capacity, except for blue daytime regime, which was reduced on mobile TSSM. These results suggest that timed LED regimes have potential to strategically manipulate plant-prey-predator interactions. We conclude that timed LED regimes can be crucial in designing integrated pest management strategies that promote both plant growth and effective biological control in controlled environments. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Response of garden strawberry cultivars to damage by the two-spotted spider mite

Garden strawberry (Fragaria x ananassa Duch.) is an important commercial berry crop. Its productivity depends on the adaptive potential of the cultivar and is limited by the degree of exposure to unfavorable abiotic and biotic factors characteristic of a particular climatic zone. The present work studies the resistance of garden strawberry cultivars with diff erent ripening periods to damage by the two-spotted spider mite (Tetranychus urticae Koch.) when grown under simulated conditions of a climatic chamber. Cultivars were observed to respond differently to simulated extreme growing conditions such as simulate d ground frost, waterlogged soil, or soil moisture defi cit combined with damage from mite spread and exposure. The cultivars Festivalnaya, Solovushka, Solnechnaya Polyanka were the least resistant to the impact of a complex of abiotic and biotic factors. For them, the extent of mite damage was up to 100 %. Moreover, a signifi cant number of dead plants were observed. The Bereginya, Nashe Podmoskovye, and Alpha cultivars are able to adapt to adverse environmental conditions. Also, they are more resistant to damage by the two-spotted spider mite.

Mechanisms underlying the effects of cyanogenesis on development and reproduction of Tetranychus urticae: Insights from enzyme activity and gene expression aspects.

Cyanogenic plants can release toxic hydrogen cyanide (HCN) to defend against herbivory by hydrolyzing the cyanogenic glycosides (CNGs) with its β-glucosidases (β-GLUs). Numerous studies have speculated this CNG-mediated toxicity by a plant-pest interaction manner. However, the specific toxic effect of HCN was not well-demonstrated because of the interference of other ingested metabolites. Additionally, the physiological- and biochemical-based mode of action of HCN were seldom determined. To fill those knowledge gaps, the two-spotted spider mite (TSSM), Tetranychus urticae, was used as a model organism to elucidate the toxic mechanism of HCN. In addition, three CNG-enzyme combinations were screened for effective cyanogenesis and TSSM lethality. Linamarin-β-GLU (lima bean-derived) presented prompt HCN release, and molecular docking indicated higher binding energy and more robust binding sites compared with other two groups, i.e., lotaustralin-β-GLU (lima bean-derived) and amygdalin-β-GLU (almond-derived). Meanwhile, this combination led to higher TSSM mortality. Moreover, we found that the median lethal concentration of this combination will significantly prolong the developmental duration, and decrease the longevity and fecundity of TSSM. Besides, the population growth was also significantly suppressed. Furthermore, the sustainable activation of enzyme activity and the encoding gene expression related to physiological process such as detoxification (cytochrome P450, glutathione S-transferase, UDP-glucuronosyltransferase and β-cyanoalanine synthase), antioxidation (superoxide dismutase, catalase and peroxidase), neural transduction (acetylcholinesterase) and respiration (cytochrome c oxidase) were attributed to the detrimental impact on development and reproduction of TSSM. The present findings can provide insight regarding reasonable utilization of toxic chemicals in pest management and creation of novel pest-resistant germplasm.

Two-spotted Spider Mite as a Factor for Occupational Asthma in Non-Farmer Apple Packing Workers

Two-spotted Spider Mite as a Factor for Occupational Asthma in Non-Farmer Apple Packing Workers

Resistance of Chitti bean genotypes of promising to two-spotted spider mite Tetranychus urticae Koch in greenhouse conditions

Resistance of Chitti bean genotypes of promising to two-spotted spider mite Tetranychus urticae Koch in greenhouse conditions

Acaricidal activity and efficacy of oxymatrine-based biopesticide against peanut red spider mite

Acaricidal activity and efficacy of oxymatrine-based biopesticide against peanut red spider mite

Infrared radiation, as a physical control method on Tetranychus urticae Koch. Under laboratory circumstances

Infrared radiation, as a physical control method on Tetranychus urticae Koch. Under laboratory circumstances

Exploration of bioactive molecules from Sesbania grandiflora (L.): identification of squalene as an effective compound against the two-spotted spider mite, Tetranychus urticae Koch, through molecular docking.

Two-spotted spider mite (TSSM), Tetranychus urticae Koch is a devastating polyphagous mite causing considerable economic loss. Acaricides are showered in crops to manage this pest. The pest is known for developing resistance to several classical acaricides. The study was aimed at the exploration of botanical acaricide for the management of TSSM, T. urticae. Adulticidal action of ethyl acetate, ethanol and water extracts of leaves of Sesbania grandiflora (Fabaceae) were tested on T. urticae. The results showed that ethyl acetate extract showed the maximum mite mortality of 94.44 per cent, followed by ethanol extract at 87.78 per cent at 5 per cent concentration. LC50 of ethyl acetate and ethanol extracts were 1.00 and 4.19 per cent, respectively. The aqueous extract gave 94.44 per cent mortality at a very high concentration of 15% with LC50 of 8.57%. Molecules from the GC-MS analysis of S. grandiflora ethyl acetate leaf extract were subjected to molecular docking using acetylcholine esterase as the target molecule. The major phytomolecules identified in the ethyl acetate leaf extract of S. grandiflora were stigmasterol (15.45%), phytol (13.60%), beta-amyrone (8.72%), and squalene (7.51%). Squalene, a biomolecule with the lowest binding energy was selected from the docking result. The toxicity of squalene was evident from the fact that it caused 81.11, 85.55 and 87.78 per cent mortality at 1800, 2000 and 2200 ppm, respectively at 48h after treatment. After, 72h, 100 per cent mortality was recorded at 1800 ppm. This study reveals that squalene can be formulated and used as the best alternative to tackle T. urticae.

Sublethal effects of chlorfenapyr and acequinocyl on the functional and numerical responses of the predatory mites Phytoseiulus persimilis and Neoseiulus californicus (Acari: Phytoseiidae) feeding on Tetranychus urticae (Acari: Tetranychidae).

Tetranychus urticae Koch, commonly known as two spotted spider mites, is a major agricultural pest that causes significant economic loss. Predatory mites, such as Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus (McGregor)are important biological control agents for this pest. However, the efficacy of these predators can be compromised by pesticide application. This study investigated the impact of two acaricides, chlorfenapyr and acequinocyl, on the functional and numerical responses of P. persimilis and N. californicus feeding on T. urticae. Bioassay tests were conducted using a leaf disk dipping method at various pesticides concentrations. Chlorfenapyr exhibited approximately five times higher toxicity than acequinocyl for both predatory mite species and N. californicus exhibited higher tolerance to both acaricides compared to P. persimilis. Functional response experiments assessed the predation rates of 10-day-old predatory mites on different densities of T. urticae nymphs. Analysis of functional response data indicated a Type II response across all treatments. The sublethal concentrations of both acaricides negatively affected the predatory efficiency of both species by reducing attack rate and daily prey consumption and increasing handling times. The numerical response data showed a reduction in egg production correlating with increased pesticide concentrations. Additionally, the efficiency of conversion of ingested food (ECI) decreased with increasing pesticide concentrations. These findings highlight the detrimental effects of pesticides on beneficial arthropods and emphasize the need for integrated pest management strategies that minimize the reliance on chemical control.