Tetranychus Urticae Research Articles

The nuclear receptor gene E75 plays a key role in regulating the molting process of the spider mite, Tetranychus urticae.

The nuclear receptor gene Ecdysone-induced protein 75 (E75), as the component of ecdysone response genes in the ecdysone signaling pathway, has important regulatory function for insect molting. However, the regulatory function of E75 during the molting process of spider mites is not yet clear. In this study, the expression pattern of E75 in the molting process of the spider mite Tetranychus urticae was analyzed. The results showed that there was a peak at 8h post-molting, followed by a decline 8h after entering each respective quiescent stage across various developmental stages. During the deutonymph stage, the expression dynamics of E75, observed at 4-h intervals, indicated that the transcript levels of TuE75 peaked at 24h, coinciding with the onset of molting in the mites. To investigate the function of TuE75 during the molting process, silencing TuE75 through dsRNA injection into deutonymph mites at the age of 8h yielded a notable outcome: 78% of the deutonymph mites were unable to progress to the adult stage. Among these phenotypic mites, 37% were incapable of transitioning into the quiescent state and eventually succumbed after a certain period. An additional 41% of the mites successfully entered the quiescent state but encountered difficulties in shedding the old epidermis, leading to eventual mortality. In summary, these results suggested that TuE75 plays a key role in the molting process of T. urticae.

Beauveria bassiana submerged spores for control of two-spotted spider mite (Tetranychus urticae Koch (Acari: Tetranychidae)): production, stability, and virulence.

In this study, IBCB 66, IBCB 868, and CBMAI 1306 isolates of Beauveria bassiana were grown in liquid culture for 4days, leading to elevated submerged spores (SS) levels. The influence of the addition of different glycerol concentrations (0, 3, and 6%) (v/v) in the liquid culture was investigated regarding the stability (at 4 and 27°C) of dried formulations. The virulence of SS was compared with aerial spores (AS) against Tetranychus urticae (Koch) (Acari: Tetranychidae). The results demonstrate the potential of using SS to control T. urticae. CBMAI 1306 and IBCB 868 isolates caused T. urticae mortality rates of 91.11% and 88.89% 5days after treatment, respectively, when applied at concentrations of 1 × 108 SS mL-1. The median Lethal Time (LT50) values for these strains were 2.64 and 2.61days, respectively. The dried formulations showed potential acaricidal activity. Higher glycerol concentrations in the liquid culture medium reduced formulation stability at 27°C.

Infestation with chewing (Spodoptera frugiperda) and piercing-sucking (Tetranychus urticae) arthropod lead to differential emission and biosynthesis of HIPVs underscoring MeSA and terpenoids in chrysanthemum foliage

Many volatiles that are induced in plant foliage as a result of herbivorous insect infestation can act as cues for natural enemy attraction or for priming defense mechanisms. However, the qualitative and quantitative differences in volatile emissions in chrysanthemum plants that are fed upon by pests with different mouthparts have not been explored. In this study, Tetranychus urticats (TEU) with piercing-sucking mouthparts and Spodoptera frugiperda larvae (FAW) with chewing mouthparts were selected to infest the Chrysanthemum morifolium leaves to determine the response of volatile emission and production induced by herbivore feeding with different mouthparts. Our results showed that FAW-infestation significantly increased the emission rate of monoterpenes and specifically induced the emission of β-pinene. In contrast, TEU-infested plants significantly enhanced the emission rate of sesquiterpenes and phenylpropanoids compared to the control group. In particular, β-funebrene and methyl salicylate (MeSA) were exclusively induced in TEU-infested plants. CmSAMTs responsible for the elicited emission of MeSA, were functionally characterized. Additionally, multiple CmTPSs with strikingly elevated expression induced by TEU and FAW-infestation were subjected to enzymatic assay for the identification of their biochemical function. The products (β-pinene, α-copaene, germacrene D, β-caryophyllene, β-funebrene and β-ylangene) of two pivotal CmTPSs covered the major terpene profiles elicited by TEU and FAW feeding. Overall, these results could deepen our understanding of the corresponding defensive strategies against herbivores feeding with different mouthparts in chrysanthemum plants and provide theoretical basis for the biological control of pests in the cultivation and production of chrysanthemum.

Evaluation of the effectiveness of some acaricides in the control of the two-spotted spider mite (Tetranychus urticae Koch) on squash crops under high plastic tunnels

Evaluation of the effectiveness of some acaricides in the control of the two-spotted spider mite (Tetranychus urticae Koch) on squash crops under high plastic tunnels

Effects of water-based extracts of peppermint ( Mentha piperita L.) and French marigold (T agetes patula L.) on the transformation of larvae and nymphs of two-spotted spider mite ( Tetranychus urticae Koch)

Effects of water-based extracts of peppermint ( Mentha piperita L.) and French marigold (T agetes patula L.) on the transformation of larvae and nymphs of two-spotted spider mite ( Tetranychus urticae Koch)

Molecular diagnostics of insecticide resistance in Australian Tetranychus urticae Koch (Acari: Tetranychidae) quarantine intercepts

AbstractAustralian ports are continuously exposed to exotic and invasive mite and insect species associated with imported fresh produce. Much effort is focused on preventing the exotic species from entering Australia by product fumigation or destruction in a timely manner. However, quarantine intercepts of invasive species may contain unwanted resistance to pesticides or carry viruses that can undermine Australian agricultural sustainability. We examined pesticide resistance status in 1275 Tetranychus urticae samples from quarantine intercepts from the Department of Agriculture, Fisheries and Forestry originating from some 29 countries spread over 6 main continents (Africa [4], Asia [12], Europe [3], North America [2], Oceania [4] and South America [4]). We used a high‐throughput multiamplicon sequencing platform to screen major target‐site mutations that cause acaricide resistance in T. urticae. These included G119S, A201S, T280A, G328A and F331Y (Ace‐1) associated with mode of action (MoA) 1 insecticide (organophosphates and carbamates); M918, L925I, L1014F and F1538I (VGSC) associated with MoA 3 insecticide (pyrethroids); G314D (GluCl1) associated with MoA 6 insecticide (avermectins and milbemycins); and finally, H92R (PSST) associated with MoA 21 insecticide (fenpyroximate, pyridaben and tebufenpyrad). The results revealed that four known mutations (G119S, T280A, G328A and F331W) were abundant in the quarantine samples including those from Norfolk Island and New Zealand. The mutations L1024V, F1538I and L925V (VGSC) associated with pyrethroid resistance were widespread through many samples, but the super Kdr mutation M918 was not detected. Similarly, H92R (PSST) that causes resistance to fenpyroximate, pyridaben and tebufenpyrad was found in most of the T. urticae intercept samples. We conclude that resistance alleles entering Australia through quarantine intercepts are common, suggesting that unwanted or rare alleles could enter Australia via this route. However, exotic quarantine breaches carrying such alleles remain of most serious concern.

Development of Ethyl Formate Disinfestation Treatment Methods for the Prevention of the Introduction and Establishment of Exotic Insect Pests in Greenhouse Cultivation

Globalization has increased international trade and caused an annual increase in the number of non-native insect pest species found in quarantine sites in Korea. Since over 80% of Korean farms use greenhouses with internal conditions conducive to growing crops and hospitable to exotic pests, efficient pest control is crucial. This study evaluated the efficacy of ethyl formate (EF) against three major exotic insect pests (Aphis gossypii, Frankliniella occidentalis, and Tetranychus urticae) and beneficial organisms (earthworms, honeybees, and silkworms) via EF fumigation experiments at two concentrations. The lethal concentration–time (LCt)99 values of A. gossypii, F. occidentalis, and T. urticae were 8.96, 14.00, and 19.07 g h/m3, respectively. Four hours of fumigation of EF at 15 g/m3 left no residue on the crops or soil after a maximum of 3 h. The beneficial organisms exhibited higher tolerance levels than A. gossypii with regard to LCt99 value, but the higher EF treatment dosage needed to control F. occidentalis and T. urticae could be highly lethal to honeybees. The lower EF dose (4 g/m3) effectively controlled A. gossypii, but 15 g/m3 was needed for F. occidentalis and T. urticae. Phytotoxicity varied in severity with EF concentration. These insights can help in developing a refined disinfestation strategy for greenhouses.

Laser interference photocuring curved surface grating lenses inspired by red spider’s eyes

We present a new method based on the bionic red spider eye’s structure to fabricate a curved surface grating lens by laser interference photocuring (LIP). These results showed that the grating structure was formed on the surface of the polarized lens with different periods ∼ 1 μm, 2 μm, and 4 μm on radius of curvature ∼ 2.8 mm, 3.8 mm, and 7.5 mm, respectively. In addition, the diffraction effect has been observed on this lens for laser at λ = 532 nm and visible light, respectively. Furthermore, the transmittance of these lenses arrived at more than 75 %. In conclusion, we explored an effective and convenient way to integrate the focus lenses and grating structure, inspired by the red spider eye.

Metabolomic study of maize leaves infested by two-spotted spider mite Tetranychus urticae

Metabolomic study of maize leaves infested by two-spotted spider mite Tetranychus urticae

Toxicological studies of Thuja orientalis plant extract and Vertimec 1.8 EC against two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae) under laboratory conditions

Toxicological studies of Thuja orientalis plant extract and Vertimec 1.8 EC against two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae) under laboratory conditions

Two-spotted Spider Mite, Tetranychus urticae Control on Okra by Portulaca oleracea Extract and Cyperus rotundus Oil

The study determined the effect of alcoholic extract of common purslane, Portulaca oleracea, Java grass, and Cyperus rotundus oil in controlling the two-spotted spider mite on okra plants. The results of laboratory experiments showed the efficiency of purslane alcoholic extract was highly toxic to adult mites, but its effect was limited on eggs. In contrast, Cyperus oil was highly effective against mite eggs and adults. Cyperus oil gave the highest mortality of 86.94%, with significant differences from the purslane extract, where 68.61% mortality was observed and differed significantly from the control treatment. An increase in mortality increased with concentration, and the highest mortality of 95.83% was achieved at 5%, compared to the mortality of 59.58% at 1% treatment. The ovicidal activity was significant after the C. rotundus oil treatment compared to the purslane extract application. Cyperus oil reduced egg hatching by 42.50%. However, purslane extract did not affect the hatching significantly (91.70% hatching) and was not significantly different from the control. In general, the hatching rate decreased with increasing concentration of Cyperus oil and was only 40% at the 5% treatment compared to 60 and 96.70% at 1% treatment and controls, respectively.. KEYWORDS :Biological control, Cyperus rotundus, Insecticidal, Ovicidal, Portulaca oleracea, Tetranychus urticae

Laboratory and field evaluation of maize resistance to the two-spotted spider mite, Tetranychus urticae

Laboratory and field evaluation of maize resistance to the two-spotted spider mite, Tetranychus urticae

Study of Thermal Requirements for the Development of Two-Spotted Mites Tetranychus urticae Koch (Acariformes: Tetranychidae), Reared on Castor Leaves (Ricinus communis L.) Under Laboratory Conditions

The two-spotted spider mite Tetranychus urticae Koch (Acariformes: Tetranychidae) is an important pest affecting several important oil crops in Iraq. The aim of this study was to determine the minimum temperature and calculate the necessary heat units for the time of development of the duration of these mites stages. The application was carried out in incubators with different temperatures (10, 15, 20, 25, 30, 35 and 40 +2 °C), relative humidity (50-60 +5%) and light: 8: 16 hours dark period on the lower surface of the grown castor leaves. newly. The results showed that the development time of the egg incubation, the larval stage, the first nymphal(protonymph) stage (active + quiescence), and the second nymphal (deutonymph) stage (active + quiescence) at temperatures 15, 20, 25, 30, and 35 °C. It decreased gradually with increasing temperature. Moreover, the egg incubation period was 8.533 and 2.067 days, the larval stage (active + quiescence) 5.821 and 1.298 days, the first nymph (protonymph) (active + quiescence) 5.521 and 1.309 days, and the second nymph (deutonymph) (active + quiescence) 5.417 and 1.150. days to the effect of 15 and 35 degrees Celsius. In addition, the development time from egg to adult was 24.972 and 5.833 days at 15 and 35 °C, respectively. The temperature threshold was 9.763, 10.693, 9.543, 10.314, and 9.957 degrees Celsius, respectively. Finally, the accumulated heat units required for the growth time of each mite cycle differed according to the different temperature threshold and growth time and the mite could not grow and develop at 10 and 40 °C.

Studies on Potential Pests of Japanese Quince (Chaenomeles japonica (Thunb.) Lindl. ex Spach) in Latvia

Abstract The objective of this research was to study potential pests of Japanese quince (Chaenomeles japonica) plantations in Latvia. Studies were carried out in eight plantations during 2017–2019. Major pests that would regularly cause significant yield losses for this plant were not observed. Black-veined white (Aporia crataegi) was considered a local pest, mass outbreaks of which can occur in individual plantations and cause significant losses of plant foliage. Four species were considered minor pests: garden chafer (Phyllopertha horticola), yellow-banded weevil (Chlorophanus viridis), silver-green weevil (Phyllobius argentatus) and copse snail (Arianta arbustorum); they are also pests of plant foliage. The European red spider mite (Panonychus ulmi) was not considered as a pest of Japanese quince. A small population was observed in summers only in one plantation, which was located next to a heavily infested orchard. Overwintering eggs were not found on the plants in any year, and we concluded that the species was an accidental immigrant in this plantation. No aphid (Aphididae) colonies were observed on the quince plants. Monitoring and evaluation of potential harmfulness of four tortrix moths – large fruit-tree tortrix (Archips podana), rose tortrix (Archips rosana), codling moth (Cydia pomonella) and holly tortrix (Rhopobota naevana) – was done. It was concluded that rose tortrix is a minor fruit pest, but the other three species were not yet considered pests of Japanese quince. Significant pests of quince flowers and fruits were not detected in our study.

Efficiency of three plant extracts for controlling Tetranychus urticae Koch (Tetranychidae) in laboratory and semi-field conditions

Efficiency of three plant extracts for controlling Tetranychus urticae Koch (Tetranychidae) in laboratory and semi-field conditions

Impacts of cultivar and management practices on the diversity and population dynamics of mites in soybean crops.

The objective of this study was to evaluate the diversity and population dynamics of mites in soybean crops with different cultivars and management practices. The study was conducted in two soybean production fields in the municipalities of Mato Queimado (L1) and Três de Maio (L2), Rio Grande do Sul state, Brazil. Two transgenic cultivars were used, and insecticide applications varied among treatments. Sampling began at the V2 stage, with 60 leaves/area/collection that were sorted, mites were collected and identified using dichotomous keys. A total of 18,100 mites belonging to 12 species were found. Among the species, Tetranychus urticae Koch, Mononychellus planki (McGregor), and Tetranychus ludeni Zacher (Tetranychidae) were the most abundant, whereas the most abundant predatory mites were the phytoseiids Neoseiulus californicus McGregor and Neoseiulus idaeus Denmark and Muma, with N. idaeus being more abundant and present in all areas. The acarofauna was influenced by environmental conditions and management practices. Neoseiulus idaeus was commonly associated with populations of M. planki, T. ludeni, and T. urticae. Neoseiulus californicus tolerated pesticide use but was affected by severe water stress, whereas N. idaeus tolerated periods of low relative humidity and high temperatures.

Effect of biorationals and Predatory Mites incontrolling the Two-Spotted Spider Mite (Tetranychus urticae L) on Eggplant field in the Greenhouse

The Two-Spotted Spider Mite (TSSM) is a prevalent mite pest found worldwide and is extensively distributed in Mongolian greenhouses. In this study, we conducted a field experiment using predatory mites and botanical pesticides on eggplants infested by TSSM. We observed promising results in terms of reducing pest populations and achieving overall improved outcomes. The experiment took place in a 120 sq.m. greenhouse located at the "Agropark" training-research center of the Mongolian University of Life Sciences. The aim of this experiment was to test the effectiveness of the following treatments in controlling Two-Spotted Spider Mite (TSSM): Treatment A (predatory phytoseiid mites at a ratio of 1:5), Treatment B (predatory phytoseiid mites + Neem), Treatment C (Neem alone), Treatment D (Neem + BEB), and Treatment E (untreated control). The experiment utilized a total of 20 plots, each with a size of 6 square meters, and 24 plants were grown in each plot, resulting in a total of 480 plants. Each plot was replicated four times. To assess TSSM control, mortality rates of TSSM were calculated for each treatment as follows: - Treatment A (Predatory phytoseiid mites): 44.4% to 94.7% - Treatment B (Predatory phytoseiid mites - 1:5 + Neem - 30ml/4.5L of water): 76.3% to 96.3% - Treatment C (Neem - 30ml/4.5L of water): 61.8% to 90.8% - Treatment D (Neem - 30ml/4.5L of water + BEB - 20ml/10L of water): 68.6% to 88.2%. The combination of all these treatments have shown apromising results in controlling TSSM in the greenhouse, significantly reducing the TSSM population, according to our research findings. However, it is important to release the predatory mites after a 5-day interval following the application of botanicals (Neem). We recommend a release of predatory mites (Phytoseiilus persimilis and Amblyseius swirskii) either alone or in combination with botanicals for controlling TSSM in the greenhouse, because it is effective and a safe plant protection measurement to use in the greenhouse.

Sustainable Strategies for the Control of Pests in Coffee Crops

Coffee is a worldwide commodity, and both coffee-producing and coffee-consuming countries have real concerns about environmental problems and economic growth strategies based on the efficient use of resources. Because this crop is a perennial, pests can significantly affect coffee production, causing considerable yield losses and threatening coffee supply and security. The presence of insects and control strategies for coffee pests is becoming a challenge. Environmental sustainability, conservation of biodiversity, and safety of the coffee seed must go hand in hand with the economic sustainability of coffee growers. This is especially important, as there has been an increase in demand for coffee and new consumer interest in differentiated quality coffee. Regular pest control methods based only on the use of synthetic pesticides are no longer effective or sustainable due to the development of insecticide resistance and negative effects on the environment, human health, and biodiversity. Thus, to ensure better control and ecological sustainability, it is crucial to reduce pesticide use by adopting original alternative strategies to maintain pest populations below the economic threshold level and towards reaching the European Green Deal. In this review, we collect information available for sustainable control of the principal coffee pests in Colombia: coffee berry borer (CBB), Hypothenemus hampei; Monalonion velezangeli; coffee root mealybugs; coffee leaf miner: Leucoptera coffeella; and the coffee red spider mite: Oligonychus yothersi. The control strategies include deep knowledge of the biology of insects and the coffee plant, their relationship with weather and habitats, as well as natural controllers. These control strategies do not involve the use of insecticides, are ecologically friendly and novel, and can be applied in other coffee-producing countries.

Control of two-spotted spider mite, Tetranychus urticae, on strawberry by integrating with cyetpyrafen and Phytoseiulus persimilis

The two-spotted spider mite (TSSM, Tetranychus urticae Koch) is a significant agricultural pest, particularly in strawberries. Management of TSSM has traditionally relied on synthetic acaricides, but to mitigate dependency on these chemicals, the control of TSSM on strawberry is often combined with biological control measures and chemical control strategies. The predatory mite, Phytoseiulus persimilis, is a promising biological control agent, preying on all TSSM developmental stages. In this study, we examined the toxicity of six common acaricides on TSSM and P. persimilis, and cyetpyrafen was selected due to its highest relative toxicity value. Then, we examined the compatibility of cyetpyrafen with P. persimilis for TSSM management on strawberries. The results suggested that cyetpyrafen revealed no substantial differences in prey consumption or longevity when compared to the control, though minor effects on the development durations of protonymphs and deutonymphs were noted in the subsequent generation. Additionally, cyetpyrafen's toxicity on key pollinators, such as Apis mellifera and Bombus terrestris, was found to be low. Thus, an integrated strategy combining cyetpyrafen (0.83 mg/L) with P. persimilis (predator–prey ratio of 1:30) was examined under laboratory and field conditions. Laboratory trials demonstrated a reduction in mites per leaf from 32.72 to 14.50 within 3 days, correlating to a 70.23% control efficiency. This efficacy increased to 96.04% by day 9 and was sustained until the experiment concluded on day 27. Field trials similarly showed a reduction in TSSM from 53.93 to 9.63 mites/leaf by day 6, achieving an 83.64% control efficiency, and culminated in a 98.46% reduction by day 10. These findings suggested that an integrated approach utilizing cyetpyrafen in conjunction with P. persimilis can be an effective alternative for TSSM management on strawberry plants.

Functional response of Neoseiulus californicus (Acari: Phytoseiidae) to Tetranychus urticae (Acari: Tetranychidae) at different temperatures.

Environmental factors like temperature have a great impact on the predation potential of biological control agents. In the present study, the functional response of the predatory mite Neoseiulus californicus (Acari: Phytoseiidae) to the pest mite Tetranychus urticae (Acari: Tetranychidae) at moderate to high temperatures under laboratory conditions was determined. The study aimed to understand the prey-predator interaction under different temperatures and prey densities. Five constant temperatures (24 °C, 27 °C, 30 °C, 33 °C, and 36 °C), and thirteen prey densities (4, 5, 8, 10, 12, 15, 16, 20, 24, 25, 30, 32, and 40) of each stage (adult, nymph, larvae, and egg stage) were employed in the experiment. Observations were made 24 h after the start of each experiment. Results revealed that the predatory mites showed type II functional response to adult females of T. urticae, whereas type I to other stages (nymphs, larvae, and eggs) of T. urticae. The predation capability of adult predatory mites on T. urticae was significant at 24-36 °C. The instantaneous attack rate (a) of N. californicus increased and the handling time (Th) decreased with an increase in temperature. The maximum attack rate was recorded at 36 °C (1.28) for the egg stage. The longest handling time was (0.78) for the larval stage of T. urticae at 30 °C. Daily consumption increased with increasing prey density. Maximum daily consumption was observed at 33 °C (30.00) at the prey density of 40. Searching efficiency decreased with the increase in prey density but was found to increase with the rise in temperature. N. californicus was found to be voracious on the larval and egg stages. Conclusively, the incorporation of N. californicus at earlier stages (larvae and eggs) of T. urticae would be beneficial under warm conditions because managing a pest at its initial stage will save the crop from major losses. The results presented in this study at various temperatures will be helpful in different areas with different temperature extremes. The results of the functional response can also be applied to mass rearing, quality testing, and integrated pest management programmes.