Research Overview on Occurrence and Control of Tetranychus urticae Koch in China

Tetranychus urticae Koch;Insecticide resistance;Chemical control This paper elaborates the occurrence factors and damage characteristics of Tetranychus urticae Koch in China,and emphatically summarizes three main control strategies of T.urticae,namely agricultural control,chemical control and biological control,as well as research progress in its resistance mechanisms.The problems existing in controlling T.urticae and its resistance management strategies are put forward,to provide a theoretical basis for the resistance management and comprehensive control of T.urticae.

Occurrence and Control of Tetranychus truncatus and T. urticae on Corns of Yanbian Area

The situation of occurrence and hazards by Tetranychus truncatus and T. urticae on corns in test garden of Agricultural College of Yanbian University were narrated in detail. The characteristics of distribution and damage by T. truncates and T. urticae, morphological characteristics, the rule of currencies and its relation- ship with environment were summarized, and the methods of comprehensive treat- ment were put out, which could effectively control the hazard degree of T. truncates and T. urticae on corns.

Acaricidal activity of different extracts from Syzygium cumini L.Skeels(Pomposia) against Tetranychus urticae Koch

Objective:To investigate the acaricidal activity of different extracts from Syzygium cumini(S.cumini)(Pomposia)againsst Tetranyckus urticae Koch(71 urticae)and the biochemical changes in antioxidants enzymes.Methods:Six extracts of S.cumini(Pomposia)at concentrations of 75,150 and 300μg/mL were used to control T.urticae(Koch).Results:The ethanol extract showed the most efficient acaricidal activity agent against T.urticae(98.5%)followed by hexane extract(94.0%),ether and ethyl acetate extract(90.0%).The LC_(50)values of the promising extract-were 85.0,101.0,102.0 and 98.0μ/mL,respectively.The activities of enzymes including ascorbate peroxidase(APX),peroxidase(POD),superoxide dismutase(SOD)and catalase(CAT)in susceptible mites were increased.The activities of all antioxidant enzymes reach the maximum value in mites at LC_(50)with ethanol and ethyl acetate extracts,respectively.Conclusions:The extract of S.cumini has acaricidal acivity against T.urticae,and the ethanol extract is the most efficient.

The Effect of Lion’s Ear (<i>Leonotis nepetifolia</i>) and African Basil (<i>Ocimum gratissimum</i>) Plant Extracts on Two-Spotted Spider Mites (<i>Tetranychus urticae</i>) for Improved Yield and Quality of French Beans

An experiment to evaluate the bio-control potential of Leonotis nepetifolia and Ocimum gratissimum plant extracts against two-spotted spider mites on French beans was conducted in the field. Five plant extract concentrations (1.5%, 3.0%, 6.0% and 12.0% w/v) were applied with water and Abamectin 0.6 ml/L as controls. Mite counts were done before and after treatment application and expressed as corrected percent efficacy. The impact of the mites on the French beans was evaluated by recording percent leaf reduction and quality and quantity by number of pods, pod length, diameter and yield. There was a dose dependent response in percent mite and leaf reduction, number of pods and yield. Treatments applied at 12% w/v indicated higher mite reduction (82.75%) for L. nepetifolia and 69.06% for O. gratissimum compared to abamectin (65.76%). The lowest percent leaf reduction of 1.71% for L. nepetifolia 0.39% for O. gratissimum and abamectin (20.46%) was also at 12% w/v. Similarly, the highest number of pod (61.00) for L. nepetifolia, 48.67 for O. gratissimum compared to 28.33 abamectin and yield (0.88 kg) for L. nepetifolia and 0.90 kg for O. gratissimum was also recorded at 12% w/v compared to 0.36 kg for abamectin. There were no significant differences in pod diameter and pod length between the extracts concentrations and abamectin. The study demonstrated the efficacy of L. nepetifolia and O. gratissimum in managing two-spotted spider mite and subsequent increase in French bean yield under field conditions.

Temperature-dependent development of Neoseiulus barked （Acari： Phytoseiidae） on Tetranychus urticae （Acari： Tetranychidae） at seven constant temperatures

The effect of seven constant temperatures of 15, 20, 25, 27, 30, 35 and 37℃ on developmental time ofNeoseiulus barkeri Hughes were determined in laboratory conditions under 65% - 5% RH and a photoperiod of 12 ： 12 （L ： D） h on nymphal stages of Tetranychus urticae Koch. Total developmental time of females （from egg to adult emergence） at the above-mentioned temperatures was 26.59, 14.43, 6.32, 5.64, 4.59, 3.98 and 4.67 days, respectively. Developmental rate of the N. barkeri increased as temperature increased from 15 to 35℃, but declined at 37℃. A linear and two nonlinear models were fitted to developmental rate of immature stages ofN. barkeri to predict the developmental rate as a function of temperature, as well as to estimate the thermal constant （K） and critical temperatures （i.e., Tmin, Topt and Tmax）. The estimated values of the Tmin and K for total developmental time using the linear model were 12.07℃ and 86.20 degree-days （DD）, respectively. The Trnin and Tmax estimated by the Sharpe-Schoolfield-Ikemoto （SSI） model were 11.90℃ and 37.41℃, respectively. The estimated Topt for overall immature stage development ofN. barkeri by the Lactin and SSI models were 33.89℃ and 24.51℃, respectively. Based on the biological criteria of model evaluation, the linear and SSI models were found to be the best models for describing the developmental rate of overall immature stages of N. barkeri and estimating the temperature thresholds.

Toxicity, inheritance and biochemistry of clofentezine resistance in Tetranychus urticae

This study evaluates the toxicological and biochemical response of two-spotted spider mites to clofentezine selection pressure. The mortality rate of Tetranychus urticae in adult females depends on increased clofentezine concentration and clofentezine was found to be effective against females. The resistance rate of the CUM strain selected 12 times once per generation with clofentezine was increased from 1.28- to 105.27-fold. The interaction of some synergists with clofentezine was analyzed in the clofentezine-resistant CLOF 12 strain. Synergists had no effect on clofentezine toxicity. The clofentezine-resistant CLOF 12 strain showed resistance against chlorpyrifos, abamectin, propargite, fenpyroximate and amitraz. The modes of inheritance of resistance to clofentezine were found to be incompletely dominant and not sex-linked. Esterase enzyme activity was detected both by gel electrophoresis and microplate reader methods, while glutathione S-transferase （GST） and monooxygenase （P450） activity were detected only by the microplate reader method. During the selection period the esterase, the GST and the P450 enzymes activities were raised from 7.69, 7.09 and 0.003 3 to 18.40, 13.11 and 0.003 7 milli-optical density/rain/rag proteins, respectively. An increase was observed in the band intensity of esterases and esterase enzymes may play a role in clofentezine resistance in T. urticae.

Frequencies and mechanisms of pesticide resistance in Tetranychus urticae field populations in China

The two-spotted spider mite Tetranychus urticate is an important agricultural pest worldwide.It is extremely polyphagous and has developed resistance to many pesticides.Here,we assessed the pesticide resistance of seven field populations of T.urticae in China,their target site mutations and the activities of their detoxification enzymes.The results showed that abamectin and the traditional pesticides pyridaben,profenofos and bifenthrin had higher resistance or lower toxicity than more recently developed pesticides including chlorfenapyr,spinetoram,cyflumetofen,cyenopyrafen,bifenazate and B-azolemiteacrylic.The frequency of point mutations related to abamectin resistance,G314D in the glutamate-gated chloride channel 1(GluCl1)and G326E in GluC13,ranged 47%-70%and 0%-97%,respectively.The frequency of point mutations in A1215D and F1538I of the voltage-gated sodium channel gene(VGSC),which may increase resistance to pyrethroids,ranged 88%-100%and 10%-100%,respectively.For target sites related to organophosphate resistance,mutation frequencies ranged 25%-92%for G119S and 0%-23%for A201S in the acetycholinesterase gene(Ace).Mutation G126S in the bifenazate resistance-related cytochrome b gene(Cytb)was observed in three of the seven T.urticae populations.Higher activities of detoxification enzymes(P450,GST,CarEs and UGTs)were observed in two T.urticae populations,with significant difference in the XY-SX population.These results provide useful information on the status of pesticide resistance of T.urticae in China and suggest that T.urticae field populations may have multiple resistance mechanisms.

Analgesic alkaloids from Urticae Fissae Herba

Objective:To investigate the analgesic substances in the aerial part of Urtica fissa(Urticae Fissae Herba),commonly used for rheumatoid and rheumatism arthritis.Methods:The analgesic constituents were isolated with the active guidance of hot plate and acetic acid writhing models,and identified by comprehensive spectroscopic analysis.Results:Thirteen alkaloids(1–13),two lignans(14,15),and three amides(16–18)were isolated from the active fractions.Among them,compound 1 was a new alkaloid,and compound 6 was a new natural product.The activity evaluation in vivo indicated that various pyrrole alkaloids(1,3,6,and 12)possessed significant analgesic activities,they could significantly inhibit the mice pain response induced by acetic acid and hot plate at the dosage of 2 mg/kg BW.Conclusion:The study revealed that the pyrrole alkaloids played important roles in the analgesic activities of Urticae Fissae Herba.

Divergent methylation pattern in adult stage between two forms of Tetranychus urticae （Acari： Tetranychidae）

The two-spotted spider mite, Tetranychus urticae Koch has two forms： green form and red form. Understanding the molecular basis of how these two forms established without divergent genetic background is an intriguing area. As a well-known epigenetic process, DNA methylation has particularly important roles in gene regulation and developmental variation across diverse organisms that do not alter genetic background. Here, to investigate whether DNA methylation could be associated with different phenotypic conse- quences in the two forms of T. urticae, we surveyed the genome-wide cytosine methylation status and expression level of DNA methyltransferase 3 （Tudnmt3） throughout their entire life cycle. Methylation-sensitive amplification polymorphism （MSAP） analyses of 585 loci revealed variable methylation patterns in the different developmental stages. In particular, principal coordinates analysis （PCoA） indicates a significant epigenetic differentiation be- tween female adults of the two forms. The gene expression of Tudnmt3 was detected in all examined developmental stages, which was significantly different in the adult stage of the two forms. Together, our results reveal the epigenetic distance between the two forms of T. urticae, suggesting that DNA methylation might be implicated in different developmental demands, and contribute to different phenotypes in the adult stage of these two forms.

The medicinal chemistry of Urtica dioica L.:from preliminary evidence to clinical studies supporting its neuroprotective activity

Urtica dioica is a perennial herb from the family of Urticaceae that is commonly known as stinging nettle.This plant is widespread in Europe,Africa,America,and a part of Asia,as it adapts to different environments and climatic condi-tions.The leaves,stalk,and bark of U.dioica found applications in the field of nutrition,cosmetics,textile,pest control and pharmacology.In this connection,bioactive chemical constituents such as flavonoids,phenolic acids,amino acids,carotenoids,and fatty acids have been isolated from the plant.With this review,we aim at providing an updated and comprehensive overview of the contributions in literature reporting computational,in vitro,pre-clinical and clini-cal data supporting the therapeutic applications of U.dioica.Experimental evidence shows that U.dioica constituents and extracts can provide neuroprotective effects by acting through a combination of different molecular mecha-nisms,that are discussed in the review.These findings could lay the basis for the identification and design of more effective tools against neurodegenerative diseases.

延边玉米截形叶螨与二斑叶螨的危害及防治

阐述了延边大学玉米试验地、大棚及温室内的截形叶螨(Tetranychus truncatus)与二斑叶螨(T.urticae)的危害状况,总结了其分布和危害特点、形态特征、发生规律及其与环境的关系,并提出综合治理的方法,以便有效控制2种叶螨的危害。

智利小植绥螨防治设施西瓜二斑叶螨的研究与应用

为探明智利小植绥螨(Phytoseiulus persimilis Athias-Henriot)防治设施西瓜二斑叶螨的关键技术和持续控害效果,研究了不同释放时期和释放量条件下智利小植绥螨对西瓜二斑叶螨的防治效果,并持续调查了连续4年释放智利小植绥螨的防治效果。结果表明,释放时期显著影响智利小植绥螨对二斑叶螨的防治效果,二斑叶螨平均数量≤2头/片叶时,释放智利小植绥螨对二斑叶螨的控制效果最好,最大防治效果为82.3%,当二斑叶螨平均数量>50头/片叶时,防治效果较差,不宜释放;释放量也显著影响智利小植绥螨对二斑叶螨的防治效果,按照25头/m^(2)和30头/m^(2)释放智利小植绥螨7、14 d的防治效果均能超过80%,14 d的防治效果显著高于43%联苯肼酯悬浮剂;连续4年定点定棚使用智利小植绥螨防治二斑叶螨,天敌释放量逐年降低,10头/m^(2)释放量即可有效控制二斑叶螨为害,防治效果为89.7%。

异株荨麻β-谷甾醇提取工艺的优化

用正交试验和方差分析研究异株荨麻(Urtica dioica L.)β-谷甾醇的超声波辅助提取工艺,以β-谷甾醇得率为指标,优选出了最佳的提取工艺。结果表明,最佳的提取工艺为料液比1∶20(m/V,g∶mL)、提取时间30 min、提取温度60℃。用超声波辅助提取异株荨麻中的β-谷甾醇,操作简单、安全、快速、萃取率高。

HPLC法测定异株荨麻茎叶中绿原酸和黄酮类化合物

建立了一种可同时测定异株荨麻(Urtica dioica L.)茎叶中绿原酸和黄酮类化合物的高效液相色谱法,色谱柱为钻石C18柱,流动相为甲醇和0.4%磷酸混合液(体积比为55/45),检测波长355 nm,柱温25℃,流速1.0 mL/min。结果表明,本法简便、快速、有效、准确、重现性好,可用于异株荨麻茎叶中绿原酸和黄酮类成分的定量分析。

Hepatoprotective effects of Nigella sativa L and Urtica dioica L on lipid peroxidation, antioxidant enzyme systems and liver enzymes in carbon tetrachloride-treated rats

AIM： To investigate the effects of Nigella sativa 1 （NS） and Urtica dioica 1 （UD） on lipid peroxidation, antioxidant enzyme systems and liver enzymes in CCl4-treated rats. METHODS： Fifty-six healthy male Wistar albino rats were used in this study. The rats were randomly allotted into one of the four experimental groups： A （CCl4-only treated）, B （CCl4＋UD treated）, C （CCl4＋NS treated） and D （CCl4＋UD＋NS treated）, each containing 14 animals. All groups received CCl4 （0.8 mL/kg of body weight, sc, twice a week for 60 d）. In addition, B, C and D groups also received daily i.p. injections of 0.2 mL/kg NS or/and 2 mL/kg UD oils for 60 d. Group A, on the other hand, received only 2 mL/kg normal saline solution for 60 d. Blood samples for the biochemical analysis were taken by cardiac puncture from randomly chosen-seven rats in each treatment group at beginning and on the 60th d of the experiment. RESULTS： The CCl4 treatment for 60 d increased the lipid peroxidation and liver enzymes, and also decreased the antioxidant enzyme levels. NS or UD treatment （alone or combination） for 60 d decreased the elevated lipid peroxidation and liver enzyme levels and also increased the reduced antioxidant enzyme levels. The weight of rats decreased in group A, and increased in groups B, C and D. CONCLUSION： NS and UD decrease the lipid peroxidation and liver enzymes, and increase the antioxidant defense system activity in the CCl4-treated rats.

Two new secolignans from the roots of Urtica mairei Levi.

Two new secolignans （1 and 2） were isolated from the roots of Urtica mairei Levi. The structures of these two compounds were determined on the basis of extensive spectroscopic methods including HR-EI-MS, 1D and 2D NMR experiments.

Antilithic Effects of Extracts from Urtica dentata Hand on Calcium Oxalate Urinary Stones in Rats

This study examined the potential antilithic effects of a traditional Chinese medicine Urtica dentata Hand （UDH） in experimental rats and screened the optimal extract of UDH as a possible therapeutic agent for kidney stones. The rat model of urinary calcium oxalate stones was induced by intragastric （i.g.） administration of 2 mL of 1.25% ethylene glycol （EG） and 1% ammonium chloride （AC） for 28 days and was confirmed by Color Doppler ultrasound imaging. The rats in different experimental groups were then intragastrically given petroleum ether extract （PEE）, N-butanol extract （NBE）, aqueous extract （AqE） of UDH, Jieshitong （positive control drug）, and saline, respectively. Treatment with NBE significantly reduced the elevated levels of urinary calcium, uric acid, phosphate, as well as increased urinary output. Accordingly, the increased calcium, oxalate levels and the number of calcium oxalate crystals deposits were remarkably reverted in the renal tissue of NBE-treated rats. In addition, NBE also prevented the impairment of renal function to decrease the contents of blood urea nitrogen （BUN） and creatinine. Taken together, these data suggest that NBE of UDH has a beneficial effect on calcium oxalate urinary stones in rats by flushing the stones out and protecting renal function.

Suitability of Nettle Fiber for Textile Production

Nettle plants widely exist in China, but up to now there is no research regarding Chinese nettle fiber properties, especially about its spinnability. This paper has studied the properties of Chinese nettle fiber and its spinnability. The research results show that the average length of nettle fiber is about 34 mm, the nettle fiber fineness ranging from 0.589 to 0.769 tex. Nettle fiber has high breaking strength, low breaking extension and high initial modulus. Both the biochemical method and chemical method can meet the requirement of nettle degumming, with the residual being less than 4%. Nettle fiber can be utilised as textile material and can be spun in rotor-spinning machines after well degummed.

Optimization of Extraction Process for Polysaccharides of Urtica fissa E. Pritz.

[Objectives] To study the optimal extraction process for polysaccharides of Urtica fissa E. Pritz. [Methods] Leaves of wild U. fissa E. Pritz. collected in Nyingchi of Tibet were used as raw materials. Water extraction method was used to extract polysaccharides from U. fissa E. Pritz. Besides,comparison was made for the effects of extraction time,extraction temperature and solid-to-liquid ratio on the yield rate of polysaccharides from U. fissa E. Pritz. In addition,using the extraction time,extraction temperature and solid-to-liquid ratio as factors,L9( 33) orthogonal experiment was carried out to determine the optimal process parameters for water extraction of polysaccharides from U. fissa E. Pritz.[Results] The optimal process parameters: hot water extraction time was 4 h,the extraction temperature was 90℃,and the mass ratio of water to leaves of U. fissa E. Pritz. was 1∶ 25. Under such extraction conditions,the yield rate of polysaccharides from U. fissa E. Pritz.was up to 11. 611%. [Conclusions]This experiment is expected to provide certain reference for reasonable development and utilization of wild U. fissa E. Pritz. resources in Tibet.

Effect of nettle(Urtica dioica) extract on gentamicin induced nephrotoxicity in male rabbits

Objective:To investigate the antioxidant ef ect of an orally administered ethanol extract of nettle(Urtica dioica) and its protective role in preventing or ameliorating oxidative stress as a major factor in gentamicin-induced nephrotoxicity in male rabbits. Methods: Twenty rabbits were divided into 4 equal groups:(G1) control group,(G2) gentamicin treated group(100 mg/kg),(G3) nettle treated group(100 mg/kg),(G4) combination treated group with both gentamicin(100 mg/kg) and nettle(100 mg/kg) for 10 days. The antioxidant properties of nettle were evaluated using dif erent antioxidant tests, such as determination of glutathione and malondialdehyde levels and total phenolic content analysis. Results: Biochemical and histopathological study revealed that gentamicin caused nephrotoxicity observed clearly in the histopathological section of the kidney in the gentamicin treated group. Serum creatinine and blood urea nitrogen were biochemical indicators for nephrotoxicity which increased signii cantly in gentamicin treated group; other groups have no signii cant change in these two parameters. Nettle extract protected the rabbits from alteration in the level of blood urea nitrogen and serum creatinine when given after inducing of gentamicin nephrotoxicity. The nettle treated group showed a great ef ect as an antioxidant factor by increasing the glutathione level and reducing malondialdehyde level. No signii cant changes in biochemical parameters and no renal histopathological changes observed in the groups treated with nettle extract, which meant nettle had powerful antioxidant activity. Conclusions: Therefore, it can be assumed that the nephroprotective ef ect shown by nettle in gentamicin-induced nephrotoxicity can reserve intracellular levels of biological pathways and supportively enhance excretion of toxic levels of gentamicin.