Adaptive evolution of the enigmatic Takakia now facing climate change in Tibet.

The most extreme environments are the most vulnerable to transformation under a rapidly changing climate. These ecosystems harbor some of the most specialized species, which will likely suffer the highest extinction rates. We document the steepest temperature increase (2010-2021) on record at altitudes of above 4,000 m, triggering a decline of the relictual and highly adapted moss Takakia lepidozioides. Its de-novo-sequenced genome with 27,467 protein-coding genes includes distinct adaptations to abiotic stresses and comprises the largest number of fast-evolving genes under positive selection. The uplift of the study site in the last 65 million years has resulted in life-threatening UV-B radiation and drastically reduced temperatures, and we detected several of the molecular adaptations of Takakia to these environmental changes. Surprisingly, specific morphological features likely occurred earlier than 165 mya in much warmer environments. Following nearly 400 million years of evolution and resilience, this species is now facing extinction.

A randomized trial of treatment for anterior cruciate ligament reconstruction by radial extracorporeal shock wave therapy.

OBJECTIVE: The aim of this study was to explore the effects of radial extracorporeal shock wave therapy (rESWT) in patients with anterior cruciate ligament(ACL) reconstruction(ACLR). METHODS: We conducted a randomized, controlled trial involving 72 eligible patients with ACL reconstruction in which we compared two strategies: the experimental group was standard rehabilitation plus rESWT and the control group was standard rehabilitation plus sham rESWT. The outcome was the change from baseline to 24 weeks in the average score on Lysholm knee joint score (LKS), range of motion (ROM), visual analogue scale (VAS) and International Knee Literature Committee (IKDC). RESULTS: Of 36 subjects assigned to rehabilitation plus rESWT, 4 lost to follow up. Of 36 assigned to rehabilitation plus sham rESWT, 5 lost to follow up. The LKS, ROM and IKDC scores of the experimental group were markedly increased at 3 and 6 weeks after treatment (P < 0.001), and the VAS was notably decreased (P < 0.001). However, there were no significant differences in the LKS, ROM, IKDC and VAS between the groups at 24 weeks after treatment (P > 0.05). CONCLUSION: The strategy of rehabilitation plus rESWT had better functional outcomes after ACL reconstruction. As such, our study demonstrates that rESWT is essential for patients with ACL reconstruction. Early use of rESWT can improve joint function, pain relief and ability of daily living. rESWT has a positive effect on the overall rehabilitation of patients.

The application of extracorporeal shock wave therapy in the treatment of temporomandibular joint disorders in a preliminary, small sample study.

OBJECTIVE: The aim of this study was to investigate the efficacy of low-intensity, high-frequency shock waves in the treatment of temporomandibular joint disorders. METHODS: Twenty-six patients with temporomandibular joint disorder admitted to the Second Hospital of Shanxi Medical University from August 2022 to December 2022 were selected as study subjects and randomly divided into two groups, A and B, with 13 patients each. In Group A, there were 5 males and 8 females with an average age of 38.85 ± 11.03 years. In Group B, there were 4 males and 9 females with an average age of 39.15 ± 11.16 years. Group A was the control group, which received routine treatment (manual massage + transcutaneous electrical nerve stimulation + ultrashort wave therapy) plus sham shock wave therapy; Group B was the experimental group, which received routine treatment (manual massage + transcutaneous electrical nerve stimulation + ultrashort wave therapy) plus shock wave therapy. The routine treatment was administered once/day, five times per week for a total of 2 weeks of treatment. In addition, shock wave therapy was administered once every 5 days, and the treatment was administered three times. The treatment period was 2 weeks, and the two groups were compared before treatment, at the end of the treatment period, and 4 weeks after treatment. The pain level of the two groups was assessed by the visual analogue scale (VAS) before and after treatment, and the temporomandibular opening index (TOI) before and after treatment was compared between the two groups. VAS and TOI scores were evaluated using the Mann-Whitney U-test, the Kruskal-Wallis H-test and two-way ANOVA. RESULTS: There was no significant difference in the VAS score and temporomandibular opening index between the two groups before treatment (p = .829 and .75, respectively). After 2 weeks of treatment, the VAS score and temporomandibular joint opening index of both groups were significantly improved compared to those before therapy. In addition, the VAS score and temporomandibular joint opening index in the experimental group were significantly better than those in the control group (p < .001 and <.001, respectively). There was a small increase in scores 4 weeks after the treatment compared to just after the treatment period, but the difference was not significant. CONCLUSION: This is a preliminary small sample study that demonstrates the positive effect of using low-intensity, high-frequency shock waves on the treatment of temporomandibular joint disorders and is worthy of clinical promotion.

Vaginal homeostasis features of Vulvovaginal Candidiasis through vaginal metabolic profiling.

Vulvovaginal candidiasis (VVC) is an inflammatory disease primarily infected by Candida albicans. The condition has good short-term treatment effects, high recurrence, and seriously affects the quality of life of women. Metabolomics has been applied to research a variety of inflammatory diseases. In the present study, the vaginal metabolic profiles of VVC patients and healthy populations (Cnotrol (CTL)) were explored by a non-targeted metabolomics approach. In total, 211 differential metabolites were identified, with the VVC group having 128 over-expressed and 83 under-expressed metabolites compared with healthy individuals. Functional analysis showed that these metabolites were mainly involved in amino acid metabolism and lipid metabolism. In addition, network software analysis indicated that the differential metabolites were associated with mitogen-activated protein kinase (MAPK) signaling and NF-κB signaling. Further molecular docking suggested that linoleic acid can bind to the acyl-CoA synthetase 1 (ACSL1) protein, which has been shown to be associated with multiple inflammatory diseases and is an upstream regulator of the MAPK and NF-κB signaling pathways that mediate inflammation. Therefore, our preliminary analysis results suggest that VVC has a unique metabolic profile. Linoleic acid, a significantly elevated unsaturated fatty acid in the VVC group, may promote VVC development through the ACSL1/MAPK and ACSL1/NF-κB signaling pathways. This study's findings contribute to further exploring the mechanism of VVC infection and providing new perspectives for the treatment of Candida albicans vaginal infection.

Candida albicans is the main pathogen that causes VVC. Through non-targeted metabolomics, this study shows that VVC caused by C. albicans has unique vaginal metabolic characteristics, the changed metabolites might provide useful diagnostic and therapeutic methods for VVC.

Insulin-induced gene 2 expression is associated with cervical adenocarcinoma malignant behavior.

BACKGROUND: The incidence of cervical adenocarcinoma (CA) as a malignant tumor has increased over the past few decades due to its low detection rate and malignant biological behaviors. Insulin-induced gene 2 (INSIG2), a membrane protein of the endoplasmic reticulum (ER), plays a crucial role in cancer progression. However, there is little known about the connection between INSIG2 and CA. METHODS: The Human Protein Atlas (HPA) and the Cancer Genome Atlas (TCGA) Cervical Cancer (CESC) data were applied to study the alteration in INSIG2 expression. Biological functions were performed to test the change of malignant behavior. Bioinformatics analysis was conducted to explore the potential affection of INSIG2 in CA progression. RESULTS: Our study confirmed that the high INSIG2 expression levels had a poor prognosis. INSIG2-knockdown inhibited the CA cell proliferation, migration, and invasion of CA cells while downregulating the epithelial-mesenchymal transition (EMT)-associated gene expression levels. Moreover, the enrichment analysis of DEGs showed more potential functions of INSIG2 in the CA progression. CONCLUSION: We found that INSIG2 knockdown may play a suppressor role in the CA progression, and may provide the potential functional influence in inhibiting of CA development.

Metabonomics profile analysis in inflammation-induced preterm birth and the potential role of metabolites in regulating premature cervical ripening.

BACKGROUND: Preterm birth (PTB) is the primary cause of infant morbidity and mortality. Moreover, previous studies have established that PTB is related to premature cervical ripening. However, the underlying mechanism remains to be elucidated. This study sought to identify differentially expressed metabolites and investigate their potential biological functions in PTB. METHODS: Pregnant C57BL/6 J mice were treated with either LPS or normal saline and cervical alterations before labor were detected by staining. Metabolic profiles in the plasma of PTB and control mice were examined through non-targeted metabonomics analyses, quantitative polymerase chain reaction and immunofluorescence staining were performed on human cervical smooth cells. RESULTS: The study demonstrated that the mRNA and protein levels of α-SMA, SM-22, and calponin in cervical smooth muscle cells of PTB mice were lower while OR was higher at both mRNA and protein levels compared to the CTL group. A total of 181 differentially expressed metabolites were analyzed, among them, 96 were upregulated, while 85 were downregulated in the PTB group. Differentially expressed metabolites may play a role in STAT3, RhoA, mTOR, TGF-ß, and NK-κB signaling pathways. Furthermore, when treated with taurine, the levels of α-SMA and SM-22 in human cervical smooth muscle cells were elevated, whereas that of connexin-43 was decreased. CONCLUSION: Our study highlighted the changes of metabolites in the peripheral blood changed prior to PTB and revealed that these differentially expressed metabolites might participate in the development of premature cervical ripening. Taurine was identified as an important metabolite may modulate human cervical smooth muscle cells. Our study provided new insights into the mechanism underlying premature cervical ripening in PTB.

YAP manipulates proliferation via PTEN/AKT/mTOR-mediated autophagy in lung adenocarcinomas.

BACKGROUND: Autophagy is a double-edged sword during the initiation and progression of multiple tumors. The Hippo pathway effector YAP has been proved to be involved in autophagy processes. The present study aimed to investigate how YAP regulates cell proliferation via autophagy in lung adenocarcinomas (LUAD). METHODS: Data of LUAD chip GSE43458 was obtained from Gene Expression Omnibus (GEO). RT-qPCR and Western blot were performed to assess YAP expression in LUAD cell lines. CCK-8 assay, xenograft tumor model, immunochemistry and GFP-mRFP-LC3 fusion proteins were utilized to evaluate the effect of YAP on autophagy of LUAD cells in vitro and in vivo. Autophagy inhibitor treatment and rescue experiments were carried out to elucidate the mechanism by which YAP manipulates autophagy in LUAD cells. RESULTS: YAP was significantly overexpressed in samples of LUAD patients and its expression level is related to 5-year survival. YAP manipulated the proliferation and autophagy in A549 and H1299 LUAD cells. YAP could induce activation of Akt/mTOR signaling pathway via suppressing PTEN in a Hippo-pathway-dependent manner. 3-Methyladenine impeded autophagy flux and promoted the proliferation in vitro and in vivo. CONCLUSIONS: Hippo pathway critical transcriptional coactivators YAP manipulates the proliferation of lung adenocarcinoma, which is regulated by PTEN/AKT/mTOR autophagic signaling.

A comprehensive analysis of IDO1 expression with tumour-infiltrating immune cells and mutation burden in gynaecologic and breast cancers.

Gynaecologic and breast cancers share some similarities at the molecular level. The aims of our study are to highlight the similarities and differences about IDO1, an important immune-related gene in female cancers. The NGS data from TCGA of cervical squamous cell carcinoma (CESC), ovarian serous cystadenocarcinoma (OV), uterine corpus endometrial carcinoma (UCEC), uterine carcinosarcoma (UCS) and breast invasive carcinoma (BRCA) were analysed to identify molecular features, and clinically significant and potential therapeutic targets of IDO1. We found IDO1 was significantly up-regulated in four gynaecologic cancers and breast cancer. According to breast cancer PAM50 classification scheme, IDO1 expression was higher in tumours of basal than other subtypes and showed better survival prognosis in BRCA and OV. Through immune infiltration analysis, we found a strong correlation between IDO1 and immune cell populations especially for dendritic cells and T cells. In addition, we investigated the association between IDO1 and tumour mutation burden (TMB) and found that IDO1 was significantly correlated with TMB in BRCA and CESC. GSVA revealed that hallmarks significantly correlated with IDO1 were involved in interferon gamma response, allograft rejection and inflammatory response. We also found PD-L1 and LAG3 were highly positive related to IDO1 in gynaecologic cancers when comparing with their corresponding normal tissues. Our results indicated that IDO1 participated in anti-tumour immune process and is correlated with mutation burden. These findings may expand our outlook of potential anti-IDO1 treatments.

Analysis of the Time-Concentration-Mortality Response of Nilaparvata lugens (Hemiptera: Delphacidae) to Paichongding.

Paichongding is an adicyclicnitromethylene neonicotinoid insecticide with a cis-configuration. Bioassay of paichongding was conducted against Nilaparvata lugens Stål under a laboratory condition. Mortality of N. lugens was analyzed by time-concentration-mortality (TCM) regressions based on the complementary log-log (CLL) model. The conditional mortalities of test individuals increased with the exposure time after treatments with different concentrations, showing that the speed of insecticidal action is concentration dependent. Meanwhile, the conditional mortalities of N. lugens increased as the concentrations of paichongding increased for all developmental stages from instars I-II to macropterous females. Correspondingly, LC(50) and LC90 values to N. lugens gradually decreased with the developmental stages, in which instars I-II were the most sensitive to paichongding, with LC(50) values of 6.31, 0.45, 0.09, and 0.03 mg/liter for 24, 48, 72, and 96 h after treatments, respectively, while macropterous females were the least sensitive among all developmental stages, with LC(50) values of 309.03, 11.48, 1.35, and 0.19 mg/liter at 24, 48, 72, and 96 h after the treatments, respectively. The time-concentration-mortality modeling was mathematically and biologically robust to evaluate the effects of paichongding on N. lugens. The results suggest that paichongding would be an effective alternative pesticide for controlling N. lugens considering its potent effects.

Physiological efects of paichongding applied to rice on the Nilaparvata lugens (Stå l), the brown planthopper.

Nilaparvata lugens (Stål) is a major rice pest in Asia. Paichongding is a novel neonicotinoid insecticide developed in 2008. The effects of this insecticide on the activity of detoxification enzymes of N. lugens and on rice resistance to the pest were examined in the laboratory. The results showed that paichongding could significantly decrease the acetylcholinesterase and GSHs transferase activities of N. lugens. The variation tendency of mixed function oxidase (MFO) activity was similar with that of the esterase. After 12 h treatment, there was no significance between the treatment and control. However, the activities of MFO and esterase increased after 24 and 48 h treatment, which suggested that MFO and esterase may play an important role in the detoxification of paichongding for N. lugens. Our results also demonstrated that treated with paichongding, damage levels of rice plants were significantly lower than those of control plants except 15 days after treatment. Compared with the control, injury indices decreased 70.22, 49.12, 34.44, and 23.23% at 3 , 6 , 9, and 12 days after paichongding treatment, respectively. The laboratory results suggested that paichongding may be effective for the control of brown planthopper.

POLE -related gene signature predicts prognosis, immune feature, and drug therapy in human endometrioid carcinoma.

The POLE subtype of Endometrial carcinoma (EC) is linked to a favourable prognosis in the molecular classification. We proposed to ascertain the potential connection between the POLE subtype and improved prognosis. In order to forecast the prognosis, least absolute shrinkage and selection operator (LASSO) Cox regression analysis and weighted gene co-expression network analysis (WGCNA) were employed, and a POLE-related risk signature (PRS) model was developed and validated. Single-sample gene set enrichment analysis (ssGSEA) with the "GSVA" package was employed to analyse immunity characteristics. Drug susceptibility studies were conducted to compare the half-maximal inhibitory concentration (IC50) of medicines between high- and low-risk groups. The PRS model was generated employing the LASSO Cox regression coefficients of the ELF1, MMADHC, andAL021707.6 genes. Our study demonstrated that the risk score was linked to tumour stage, grade, and survival. Furthermore, the low-risk group possessed elevated levels of gene expression connected with immunological checkpoints and HLA. Our outcomes emerged that the PRS model might have value in identifying patients with a good prognosis and in facilitating personalised treatment in the clinic.

Arachidonic acid inhibit granulosa cell function by affecting metabolic function of liver in brown adipose transplantation rats.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a gynecological endocrine disease and could be considered a metabolic disease because it is often accompanied by obesity and insulin resistance. Brown adipose tissue (BAT) transplantation has been shown to be effective in treating PCOS rats. RESULTS: The study demonstrated that BAT successfully recovered the reproductive and metabolic phenotype of PCOS rats. The disorder estrous cycle, abnormal hyperglycemia and the expression of liver factors were improved. Differentially expressed metabolites were analyzed, among them, arachidonic acid may play a role in inhibiting cell proliferation, enhancing oxidative stress reaction, promoting estrogen expression, and reducing progesterone level in KGN cells. CONCLUSION: Our findings suggest that BAT transplantation may be a therapeutic strategy for PCOS by changing the expression of some cytokines and metabolites. Differentially expressed metabolites might be crucially important for the pathogenesis of PCOS.

Study on methane degradation by microbial agents based on chelating wetting agent carriers.

Due to the low permeability characteristics of the deep gas-containing coal seam, the conventional prevention and control measures that cannot solve the problems of gas outbursts are unsatisfactory for the prevention and control of the coal and gas outbursts disaster. Therefore, in this study, a strain of methane-oxidizing bacteria M07 with high-pressure resistance, strong resistance, and high methane degradation rate was selected from coal mines. The growth and degradation abilities of M07 in chelating wetting agent solutions to assess its adaptability and find the optimal agent-to-M07 ratio. It provides a new method for integrating the reduction of impact tendency and gas pressure in deep coal mines. The experimental results show that M07 is a Gram-positive bacterium of the genus Bacillus, which has strong resistance and adaptability to high-pressure water injection. By degrading 70 mol of methane, M07 produces 1 mol of carbon dioxide, which can reduce gas pressure and reduce the risk of gas outbursts in coal mines. As the experiment proves, the best effect was achieved when the M07 concentration of the chelating wetting agent was 0.05%. The methane-oxidizing bacteria based on the chelating wetting agent as carriers prove a new prevention and control method for the integrated prevention and control of coal and gas outbursts in coal mines and also provide a new idea for microbial application in coal mine disaster control.

Sublethal effects of paichongding on Nilaparvata lugens (Homoptera: Delphacidae).

Nilaparvata lugens (Stål) is a major rice pest in Asia Paichongding is a novel neonicotinoid insecticide developed in 2008. The effects of this insecticide on life-table parameters and wing formation of N. lugens were examined in the laboratory. The results showed that paichongding could significantly reduce the fecundity of N. lugens, demonstrating further activity against this pest in addition to direct toxicity. The fecundity of N. lugens treated with LC20, LC30, LC40, and LC50 of paichongding were 87.44, 79.63, 63.31, and 52.66% of the control, respectively. The relative fitness values were 0.55, 0.41, 0.21, and 0.09, respectively, for LC20, LC30, LC40, and LC50 paichongding treatments. Sublethal concentrations of paichongding showed significant induction of macropterous offspring, which would be one kind of coping mechanism of N. lugens response to insecticide stress.

Differences in metabonomic profiles of abdominal subcutaneous adipose tissue in women with polycystic ovary syndrome.

Introduction: Polycystic ovary syndrome (PCOS) is a complex endocrine disorder that often coexists with a metabolic disorder. Studies have demonstrated that the malfunction of adipose tissue, particularly abdominal adipose tissue, could exacerbate reproductive and metabolic problems in PCOS patients. Adipose tissue-secreted signaling mediators (e.g., lipids and metabolites) would then interact with other body organs, including the ovary, to maintain the systemic equilibrium. Methods: In this study, we examined adipose samples from PCOS patients and unaffected individuals using a liquid chromatography-mass spectrometry-based metabonomics approach (LC-MS/MS). PCOS biomarkers were selected using multivariate statistical analysis. Results: Our pathway analysis revealed that these differential metabolites could be engaged in inflammatory diseases and mitochondrial beta-oxidation. We further developed an in vitro PCOS cell model to examine the effects of hyperandrogenism on granulosa cells and related metabolic disorders. We noted that isoleucine recovered the promotive effect on cell apoptosis, inhibitory effect on cell proliferation, sex hormone secretion, and mitochondrial function induced by dehydroepiandrosterone. Our gas chromatography-mass spectrometry targeted analysis (GC-MS/MS) revealed that isoleucine was significantly decreased in PCOS patients. Discussion: Based on these results, we speculate that metabolome alterations are vital in ameliorating PCOS symptoms. This may be a novel therapeutic target for PCOS treatment. Our study provides preliminary evidence that these findings will enhance our ability to accurately diagnose and intervene in PCOS.

Association of Glycosylation-Related Genes with Different Patterns of Immune Profiles and Prognosis in Cervical Cancer.

(1) Background: Although the application of modern diagnostic tests and vaccination against human papillomavirus has markedly reduced the incidence and mortality of early cervical cancer, advanced cervical cancer still has a high death rate worldwide. Glycosylation is closely associated with tumor invasion, metabolism, and the immune response. This study explored the relationship among glycosylation-related genes, the immune microenvironment, and the prognosis of cervical cancer. (2) Methods and results: Clinical information and glycosylation-related genes of cervical cancer patients were downloaded from the TCGA database and the Molecular Signatures Database. Patients in the training cohort were split into two subgroups using consensus clustering. A better prognosis was observed to be associated with a high immune score, level, and status using ESTIMATE, CIBERSORT, and ssGSEA analyses. The differentially expressed genes were revealed to be enriched in proteoglycans in cancer and the cytokine-cytokine receptor interaction, as well as in the PI3K/AKT and the Hippo signaling pathways according to functional analyses, including GO, KEGG, and PPI. The prognostic risk model generated using the univariate Cox regression analysis, LASSO algorithm and multivariate Cox regression analyses, and prognostic nomogram successfully predicted the survival and prognosis of cervical cancer patients. (3) Conclusions: Glycosylation-related genes are correlated with the immune microenvironment of cervical cancer and show promising clinical prediction value.

Neural mechanisms of priming effects of spicy food pictures induced analgesia.

In this study, the effects of the priming of spicy food pictures on pain perception were evaluated in female participants using standardized methods of pain. Results from behavior tests revealed that the priming of spicy food pictures significantly reduced pain perception, particularly at high-pain intensities. Electrophysiological analysis showed that the analgesic effects of spicy food pictures were linked to decreased pain-related event-related potentials, such as N2 and P2 amplitudes, and suppressed θ-oscillations in the sensorimotor cortex. Both N2 amplitudes and θ-oscillations activities were found to be correlated with participants' pain perception. These results suggest that spicy-arousal stimuli may act as an "antagonist" to the increase in N2 amplitudes and θ-oscillations power induced by pain and influence the neuronal networks involved in integrating spontaneous nociceptive resources, which supports the dissociation theory of pain sensation and affection. These findings highlight the potential use of spicy-arousal stimuli as an analgesic and emphasize the importance of considering both the intensity of the stimuli and the individual's emotional state in the assessment and treatment of pain.

Study on the effect of SDBS and SDS on deep coal seam water injection.

Coal seam water injection, as an important disaster prevention means in the process of coal mining, can effectively suppress coal dust, add water injection additives, can effectively improve the wettability of coal body, improve the permeability of coal body, so as to achieve the prevention of rock burst. To improve the wettability of coal in coal seam water injection, the surfactant is often added to water, but sodium dodecyl benzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS) have limitations in improving wettability of deep coal seam by injecting water. Therefore, it is very important to determine the influencing factors of SDBS and SDS to improve the wettability of coal. In this paper, the effects of oxygen-containing functional groups and minerals in coal on the wettability of coal are revealed, and the wettability mechanism of SDBS and SDS is expounded from the microscopic point of view. SEM was used to characterize the interaction between coal surface and surfactant, and the contact angle experiment was used to verify the influence of minerals in coal on wettability. Inductively coupled plasma atomic emission spectroscopy (ICP) and dynamic light scattering (DLS) tests were used to characterize the interaction of SDBS, SDS with minerals and the size of precipitation generated by the interaction of SDBS, SDS and mineral ions. The results showed that SDBS and SDS interact with Ca2+ to produce precipitation and block the flow of water in coal, which is not conducive to improving the wettability of deep coal seam to a certain extent. The significant chelating effect of chelating agent and Ca2+ provides a feasible solution to this problem.

Application of chitosan with different molecular weights in cartilage tissue engineering.

Cartilage tissue engineering involves the invention of novel implantable cartilage replacement materials to help heal cartilage injuries that do not heal themselves, aiming to overcome the shortcomings of current clinical cartilage treatments. Chitosan has been widely used in cartilage tissue engineering because of its similar structure to glycine aminoglycan, which is widely distributed in connective tissues. The molecular weight, as an important structural parameter of chitosan, affects not only the method of chitosan composite scaffold preparation but also the effect on cartilage tissue healing. Thus, this review identifies methods for the preparation of chitosan composite scaffolds with low, medium and high molecular weights, as well as a range of chitosan molecular weights appropriate for cartilage tissue repair, by summarizing the application of different molecular weights of chitosan in cartilage repair in recent years.

Evaluation of the predatory mite Amblyseius hainanensis (Acari: Phytoseiidae) and artificial rainfall for the management of Brevipalpus obovatus (Acari: Tenuipalpidae).

Brevipalpus obovatus Donnadieu is an important pest mite on tea plants in South China. In the current study, predatory mites of B. obovatus in the tea gardens of Guangzhou were extensively surveyed. In total, 13 species of predatory mites (four families with seven genera) were recorded. The population proportion of Amblyseius hainanensis Wu et Qian was the highest (68.6 %), followed by that of Anystis baccarum (L.) (8.4 %) and A. theae Wu (6.3 %). The effects of starvation time, habitat size and pest population density on the predatory efficiency of the most dominant species, A. hainanensis, feeding on B. obovatus were assessed. In addition, the effectiveness of artificial rainfall in reducing B. obovatus populations was evaluated. After starvation for 48 h, the predatory efficiency of A. hainanensis was significantly higher than those that had been starved for 24 or 72 h when 30-50 B. obovatus eggs were made available. The predation of A. hainanensis on B. obovatus also increased with increasing prey density. The number of prey attacked by A. hainanensis in a 3.2 cm(2) habitat was significantly higher than in a 6.3 cm(2) habitat. The average predation of A. hainanensis was 31.7 eggs per day when offered 100 B. obovatus eggs on a tea leaf. This decreased to 17.8 eggs per day when four A. hainanensis shared 100 B. obovatus eggs. B. obovatus populations can be reduced by artificial rainfall, with the reduction affected by rainfall intensity. With an intensity of 40 mm in 15 min, 90.2 % mortality of B. obovatus occurred; lower mortalities were recorded (13.3 and 29.8 %) when the intensity was 2 or 4 mm in 15 min. Combination of the predatory mite A. hainanensis and artificial rainfall for the integrated pest management of B. obovatus is discussed.