Silencing of an odorant binding protein (SaveOBP10) involved in the behavioural shift of the wheat aphid Sitobion avenae (Fabricius).

Insects are highly reliant on their active olfactory system in which odorant binding proteins play a role to selectivity and sensitivity during odour perception and processing. This study sets out to determine whether and to which extent the antennal loaded SaveOBP10 in English grain aphid Sitobion avenae, contributes in olfactory processing during host selection. To understand this possible relationship, we purified the SaveOBP10 recombinant protein and performed fluorescence ligand binding tests, molecular docking, RNA interference (RNAi) and behavioural trials. The results showed that SaveOBP10 had strong binding affinities (Ki ≤5 µM) with most of wheat plant volatiles at pH 5.0 as compared to pH 7.4. In Y-tube olfactometer bioassays, the S. avenae was attracted behaviourally towards pentadecane, butylated hydroxytoluene, tetradecane and ß-caryophyllene however repelled by naphthalene. After RNAi of SaveOBP10, the aphid showed nonattraction towards ß-caryophyllene and nonsignificant behavioural response to pentadecane, butylated hydroxytoluene and tetradecane. Furthermore, the three-dimensional structure modelling and molecular docking of SaveOBP10 were performed to the volatiles with high binding abilities. Together these findings indicate that SaveOBP10 can bind more strongly to the volatiles that involved in S. avenae behaviour regulation and possibly will contribute effectively in S. avenae integrated pest management.

Expression Profiles and Biochemical Analysis of Chemosensory Protein 3 from Nilaparvata lugens (Hemiptera: Delphacidae).

Insects have evolved highly sensitive olfactory sensory systems to detect plant hosts and mates, with plant volatiles playing an important role in informing insect behavior. Chemosensory proteins (CSPs) are thought to play a key role in this process, but in this respect, there is limited information on brown planthopper Nilaparvata lugens, one of the most destructive pests of rice. To expand our understanding of CSP function in N. lugens we explored expression profiles and binding characteristics of NlugCSP3. The ligands with higher binding affinity were also validated by molecular docking and behavioral assays. NlugCSP3 mRNA was expressed at relatively higher levels in antennae and abdomen of 3-day-old unmated macropterous males as well as in antennae of 3-day mated macropterous and brachypterous females. Fluorescence competitive binding assays revealed that 5 out of 25 candidate volatiles are strong binders (Ki < 10 µM). Behavioral assays revealed that nonadecane and 2-tridecanone, which have high binding affinities in fluorescence competition-binding assays, displayed strong attractiveness to N. lugens. Pursuing this further, molecular docking analysis identified key amino acid residues involved in binding volatile compounds. Overall, our data provide a base for further investigation of the potential physiological functions of CSP3 in Nilaparvata lugens, and extend the function of NlugCSP3 in chemoreception of N. lugens.

An Odorant Binding Protein (SaveOBP9) Involved in Chemoreception of the Wheat Aphid Sitobion avenae.

Odorant binding proteins play a key role in the olfactory system and are involved in the odor perception and discrimination of insects. To investigate the potential physiological functions of SaveOBP9 in Sitobion avenae, fluorescence ligand binding experiments, molecular docking, RNA interference, and behavioral tests were performed. Fluorescence binding assay results showed that SaveOBP9 had broad and high (Ki < 10 µM) binding abilities with most of the wheat volatiles, but was more obvious at pH 7.4 than pH 5.0. The binding sites of SaveOBP9 to the volatiles were predicted well by three-dimensional docking structure modeling and molecular docking. Moreover, S. avenae showed a strong behavioral response with the four compounds of wheat. The reduction in mRNA transcript levels after the RNA interference significantly reduced the expression level of SaveOBP9 and induced the non-significant response of S. avenae to the tetradecane, octanal, decanal, and hexadecane. This study provides evidence that SaveOBP9 might be involved in the chemoreception of wheat volatile organic compounds and can successfully contribute in the integrated management programs of S. avenae.

Prediction of Protein Submitochondrial Locations by Incorporating Dipeptide Composition into Chou's General Pseudo Amino Acid Composition.

Mitochondrion is the key organelle of eukaryotic cell, which provides energy for cellular activities. Submitochondrial locations of proteins play crucial role in understanding different biological processes such as energy metabolism, program cell death, and ionic homeostasis. Prediction of submitochondrial locations through conventional methods are expensive and time consuming because of the large number of protein sequences generated in the last few decades. Therefore, it is intensively desired to establish an automated model for identification of submitochondrial locations of proteins. In this regard, the current study is initiated to develop a fast, reliable, and accurate computational model. Various feature extraction methods such as dipeptide composition (DPC), Split Amino Acid Composition, and Composition and Translation were utilized. In order to overcome the issue of biasness, oversampling technique SMOTE was applied to balance the datasets. Several classification learners including K-Nearest Neighbor, Probabilistic Neural Network, and support vector machine (SVM) are used. Jackknife test is applied to assess the performance of classification algorithms using two benchmark datasets. Among various classification algorithms, SVM achieved the highest success rates in conjunction with the condensed feature space of DPC, which are 95.20 % accuracy on dataset SML3-317 and 95.11 % on dataset SML3-983. The empirical results revealed that our proposed model obtained the highest results so far in the literatures. It is anticipated that our proposed model might be useful for future studies.

Nexus of the CSR disclosures and corporate financial performance: evidence from Asian countries climate policy uncertainty.

Financial performance is a critical aspect of a company's overall health and sustainability. It directly influences investor decisions, stock market performance, credit ratings, and the company's ability to access capital. Corporate financial performance is influenced by multitude of facts, both internal and external such as disclosure of the information, and social and environmental factors. On the ground of the facts, we aimed to investigate non-financial firms that belong to Asian economies affected by climate policy uncertainty and corporate social responsibility disclosures in terms of their financial performance. To conduct quantitative study analysis, we used the two effective statistical tools such as two-stage regression method and generalized method of movement (GMM). Our results show that corporate high value of social responsibility disclosure and climate policy uncertainty has significant negative impact on return on asset (ROA) of the listed organizations of China, Pakistan, and India. Moreover, CSR disclosure attributes higher values such as social (SC) and governance score (GOV), and climate policy uncertainty (CPU) has significant negative relationship with return on equity (ROE) and earning per share (EPS) respectively, while a higher value of ESG total score and the environmental (ENV) score has a significant positive impact on ROE and EPS. Additionally, the research concludes that climate policy uncertainty is a key factor that motivates CSR disclosure practices, which ultimately improves corporate financial performance. Moreover, we concluded from our finding that the climate policy uncertainty creates ambiguity surrounding government regulations, international agreements, or market mechanisms that affect financial performance. Moreover, environmental disclosure information that has the large part in total ESG scores attract the investors around the globe which leads to rise in the financial performance, while the other attributes of the CSR disclosure decrease performance. This study advocated the great implications for researchers, investors, the government, and regulatory authorities. Policy makers can make the policy about the CSR disclosure for creating the good image of the organization to attract investors around the globe.

Role of the government towards stock markets and carbon emissions: evidence from wavelet approach.

The government of any country can play a great role in promoting economic and environmental policy reforms in both normal and crisis periods, but during the crisis period, the role of the government should take the economy into a recovery position. The stock market is the backbone of the financial system that needs the government's attention, especially in the period of financial stress and environmental protection is the responsibility of every economy to live in a healthy environment. Combining this motive, this study analyzed the role of the government towards the stock market and carbon emission by using different approaches, including the wavelet approach, OLS regression, and the Granger causality test. The wavelet approach is useful for analyzing the role of the government at different time intervals by using the time horizon from 1993 to 2021. World governance's six indicators in terms of voice and accountability, control of corruption, rules of law, regulatory quality, political stability, and government effectiveness are used as the proxy for the role of the government. Our findings show that all WGI indicators have a positive relationship with the stock market of Malaysia except voice and accountability while concerning voice and accountability, the role of the government of Malaysia is negative on the stock market. Similarly, our findings also show that the effective government governance mechanism through WGI indicators has a significant positive impact on CO2 emission due to industrialization. Furthermore, findings of the Granger causality test reveal that all the WGI indicators cause to stock market of Malaysia, and political stability has bi-directional causality indicating stock market index is also a factor that caused the political stability within Malaysia. In the Granger causality results of the CO2 and WGI indicators, there is unidirectional causality found between rules of law and regulatory quality with CO2 emission. This study advocated strong implementations for the investors for investment decisions in effective governance countries and implications for the government to remove their weakness by making effective governance related to the economy and as well as the environments within the country.

Risk and causality Co-movement of Malaysia's stock market with its emerging and OECD trading partners. Evidence from the wavelet approach.

The growing trend of interdependence between the international stock markets indicated the amalgamation of risk across borders that plays a significant role in portfolio diversification by selecting different assets from the financial markets and is also helpful for making extensive economic policy for the economies. By applying different methodologies, this study undertakes the volatility analysis of the emerging and OECD economies and analyzes the co-movement pattern between them. Moreover, with that motive, using the wavelet approach, we provide strong evidence of the short and long-run risk transfer over different time domains from Malaysia to its trading partners. Our findings show that during the Asian financial crisis (1997-98), Malaysia had short- and long-term relationships with China, Germany, Japan, Singapore, the UK, and Indonesia due to both high and low-frequency domains. Meanwhile, after the Global financial crisis (2008-09), it is being observed that Malaysia has long-term and short-term synchronization with emerging (China, India, Indonesia), OECD (Germany, France, USA, UK, Japan, Singapore) stock markets but Pakistan has the low level of co-movement with Malaysian stock market during the global financial crisis (2008-09). Moreover, it is being seen that Malaysia has short-term at both high and low-frequency co-movement with all the emerging and OECD economies except Japan, Singapore, and Indonesia during the COVID-19 period (2020-21). Japan, Singapore, and Indonesia have long-term synchronization relationships with the Malaysian stock market at high and low frequencies during COVID-19. While in a leading-lagging relationship, Malaysia's stock market risk has both leading and lagging behavior with its trading partners' stock market risk in the selected period; this behavior changes based on the different trade and investment flow factors. Moreover, DCC-GARCH findings shows that Malaysian market has both short term and long-term synchronization with trading partners except USA. Conspicuously, the integration pattern seems that the cooperation development between stock markets matters rather than the regional proximity in driving the cointegration. The study findings have significant implications for investors, governments, and policymakers around the globe.

The temporal-spatial expression and functional analysis of three gustatory receptor genes in Solenopsis invicta using sweet and bitter compounds.

The insect gustatory system participates in identifying potential food sources and avoiding toxic compounds. During this process, gustatory receptors (GRs) recognize feeding stimulant and deterrent compounds. However, the GRs involved in recognizing stimulant and deterrent compounds in the red imported fire ant, Solenopsis invicta, remain unknown. Therefore, we conducted a study on the genes SinvGR1, SinvGR32b, and SinvGR28a to investigate the roles of GRs in detecting feeding stimulant and deterrent compounds. In this current study, we found that sucrose and fructose are feeding stimulants and the bitter compound quinine is a feeding deterrent. The fire ant workers showed significant behavior changes to avoid the bitter taste in feeding stimulant compounds. Reverse transcription quantitative real-time polymerase chain reaction results from developmental stages showed that the SinvGR1, SinvGR32b, and SinvGR28a genes were highly expressed in fire ant workers. Tissue-specific expression profiles indicated that SinvGR1, SinvGR32b, and SinvGR28a were specifically expressed in the antennae and foreleg tarsi of workers, whereas SinvGR32b gene transcripts were also highly accumulated in the male antennae. Furthermore, the silencing of SinvGR1 or SinvGR32b alone and the co-silencing of both genes disrupted worker stimulation and feeding on sucrose and fructose. The results also showed that SinvGR28a is required for avoiding quinine, as workers with knockdown of the SinvGR28a gene failed to avoid and fed on quinine. This study first identified stimulant and deterrent compounds of fire ant workers and then the GRs involved in the taste recognition of these compounds. This study could provide potential target gustatory genes for the control of the fire ant.

The effects of the COVID-19 pandemic period on stock market return and volatility. Evidence from the Pakistan Stock Exchange.

The COVID-19 pandemic has emerged as a significant event of the current century, introducing substantial transformations in economic and social activities worldwide. The primary objective of this study is to investigate the relationship between daily COVID-19 cases and Pakistan stock market (PSX) return volatility. To assess the relationship between daily COVID-19 cases and the PSX return volatility, we collected secondary data from the World Health Organization (WHO) and the PSX website, specifically focusing on the PSX 100 index, spanning from March 15, 2020, to March 31, 2021. We used the GARCH family models for measuring the volatility and the COVID-19 impact on the stock market performance. Our E-GARCH findings show that there is long-term persistence in the return volatility of the stock market of Pakistan in the period of the COVID-19 timeline because ARCH alpha (ω1) and GARCH beta (ω2) are significant. Moreover, is asymmetrical effect is found in the stock market of Pakistan during the COVID-19 period due to Gamma (ѱ) being significant for PSX. Our DCC-GARCH results show that the COVID-19 active cases have a long-term spillover impact on the Pakistan stock market. Therefore, the need of strong planning and alternative platform should be needed in the distress period to promote the stock market and investor should advised to make diversified international portfolio by investing in high and low volatility stock market to save their income. This study advocated the implications for investors to invest in low volatility stock especially during the period of pandemics to protect their return on investment. Moreover, policy makers and the regulators can make effective policies to maintain financial stability during pandemics that is very important for the country's economic development.

Moderating role of political stability and economic policy uncertainty between country governance practice and stock market performance. A comparative analysis of Pakistan and Kurdistan Region of Iraq.

The objective of the study is to explore the relationship between country governance practices along with political stability and Economic policy uncertainty, and stock market performance of two different economies, Pakistan and Kurdistan region of Iraq. To meet our objectives, we used the 25 years past data from 1996 to 2021. Data is collected from the DataStream database. The regression analysis is used as the method of estimation for linear and moderation effect. Our results show that regulatory quality, rules of law and political stability has significant positive relationship with stock market performance of Pakistan, but all the governance indicators have significant positive relationship with stock market performance of the Kurdistan Region of Iraq. Moreover, political stability has significant moderating impact between the governance practices and the performance of the stock markets of both economies indicating that the governance practices perform well with the political stability that leads to rise in the stock market indices of selected countries. Economic policy uncertainty has significant negative moderation impact due to creating the risk in both economies that decrease the performance of the stock markets of the selected economies. Finally, our study advocated some implications for the investors to increase their confidence on the stock of high political stability and low economic policy uncertainty economies. Government can take significant measures to control the uncertainty of the policy and portfolio managers can adjust their risk on the ground of the political stability and efficient governance practices countries.

Juvenile hormone induces reproduction via miR-1175-3p in the red imported fire ant, Solenopsis invicta.

Juvenile hormone (JH) acts in the regulation of caste differentiation between queens and workers (i.e., with or without reproductive capacity) during vitellin synthesis and oogenesis in social insects. However, the regulatory mechanisms have not yet been elucidated. Here, we identified a highly expressed microRNA (miRNA), miR-1175-3p, in the red imported fire ant, Solenopsis invicta. We found that miR-1175-3p is prominently present in the fat bodies and ovaries of workers. Furthermore, miR-1175-3p interacts with its target gene, broad-complex core (Br-C), in the fat bodies. By utilizing miR-1175-3p agomir, we successfully suppressed the expression of the Br-C protein in queens, resulting in reduced vitellogenin expression, fewer eggs, and poorly developed ovaries. Conversely, decreasing miR-1175-3p levels led to the increased expression of Br-C and vitellogenin in workers, triggering the "re-development" of the ovaries. Moreover, when queens were fed with JH, the expression of miR-1175-3p decreased, whereas the expression of vitellogenin-2 and vitellogenin-3 increased. Notably, the suppression of fertility in queens caused by treatment with agomir miR-1175-3p was completely rescued by the increased vitellogenin expression induced by being fed with JH. These results suggest the critical role of miR-1175-3p in JH-regulated reproduction, shedding light on the molecular mechanism underlying miRNA-mediated fecundity in social insects and providing a novel strategy for managing S. invicta.

Research on dye sensitized solar cells: recent advancement toward the various constituents of dye sensitized solar cells for efficiency enhancement and future prospects.

It is universally accepted that the financial advancement of a state is essentially dependent upon the energy sector as it is essential in the growth, development, and improvement of the farming, mechanical, and defense sectors. A dependable source of energy is expected to enhance society's expectation of everyday comforts. Modern industrial advancement, which is indispensable for any nation, relies upon electricity. The principal explanation behind the energy emergency is rapidly increasing the use of hydrocarbon resources. Thus, the use of renewable resources is essential to overcome this dilemma. The consumption of hydrocarbon fuels and their discharge has destructive consequences on our surroundings. Third-generation photovoltaic (solar) cells are latest encouraging option in solar cells. Currently, dye-sensitized solar cells (DSSC) utilize organic (natural and synthetic) dye and inorganic (ruthenium) as a sensitizer. The nature of this dye combined with different variables has brought about a change in its use. Natural dyes are a feasible alternative in comparison to expensive and rare ruthenium dye owing to their low cast, easy utility, abundant supply of resources, and no environmental threat. In this review, the dyes generally utilized in DSSC are discussed. The DSSC criteria and components are explained, and the progress in inorganic and natural dyes is monitored. Scientists involved in this emerging technology will benefit from this examination.

An environmental field assessment of soil quality and phytoremediation of toxic metals from saline soil by selected halophytes.

The current study has aims to investigate the soil quality and phytoextraction of cadmium (Cd), chromium (Cr), and lead (Pb) from saline soils using Alhagi maurorum (camelthorn), Tamarix aphylla (saltcedar), Salvadora persica (mustard bush), and Suaeda nigra (bush seep weed). The saline bulk soil, rhizospheric soil, and different parts of selected plants were oxidized using the acid mixture and determined Cd, Cr, and Pb by atomic absorption spectrometry. The bio-concentration factor (BCF) and translocation factor (TF) of also examined. The quality parameters of soil like pH (< 8.5), and electrical conductivity (EC; > 4.00 dS m-1) indicated the soil is saline. The salinity of soil was lower the organic matters, and total nitrogen contents in studied saline bulk soil due to deterioration condition of soils. However, the rhizospheric soil showed the improved quality of saline soil reflected the good phytoextraction of salts from saline soil. The high contents of Cd in roots and shoots (1.02 and 0.65 µg g-1) of Alhagi maurorum, Cr in the roots and shoots (6.20, and 6.75 µg g-1) of Tamarix aphylla and Pb in the roots and shoots (5.63, and 5.75 µg g-1) of Suaeda nigra. The BCF and TF showed the Tamarix aphylla and Alhagi maurorum for Pb, Alhagi maurorum, and Salvadora persica for Cr considered as hyperaccumulator plants. Based on BCF and TF values of Alhagi maurorum, Tamarix aphylla for Cd, and Salvadora persica for Cr and Pb have the efficiency to uptake toxic metals from saline soil. Thus, it can be concluded that selected plant species may have ability for the phytoextraction the Cd, Cr and Pb from saline soil.

Appraisal of MsepCSP14 for chemosensory functions in Mythimna separata.

Chemosensory proteins (CSPs) have great contributions in performing diverse functions in insects. However, physiological appraisal of chemosensory protein genes still remains elusive in insects. We studied expression patterns and binding affinities of MsepCSP14, a chemosensory protein, in Mythimna separata. The distinct functions of MsepCSP14 were validated by employing different molecular techniques. The MsepCSP14 had high resemblance of sequence with chemosensory proteins of other insect family members. The MsepCSP14 expression was higher in antennal tissues of females than other tissues. Fluorescence binding assay validated that binding of nine out of 21 ligands to MsepCSP14 was higher at pH 7.4 than at pH 5.0. Three dimensional modeling (3D) and docking analysis predicted that amino acid residues of MsepCSP14 were involved in binding of compounds, and behavior assay displayed that adults of M. separata considerably responded to four volatiles from compounds demonstrating strong binding ability to MsepCSP14. Results of the present study suggest that MsepCSP14 is likely to mediate chemosensory functions in M. separata.

Respiratory dyskinesia--an under-recognized side-effect of neuroleptic medications.

Respiratory dyskinesia is an under-recognized side effect of neuroleptic administration. There are only few studies that have addressed the prevalence of respiratory dyskinesia in patients with tardive dyskinesia. Our case report highlights the need to regularly examine patients on antipsychotics for any evidence of dyskinetic movements including respiratory musculature. Since RD is underrecognized and misdiagnosed, early detection can improve long term prognosis as treatment options are few and usually of only limited effect. A 62-year-old Asian male, retired civil engineer, had more than 20 years history of depressive illness, developed antidepressant induced hypomania, and was given risperidone upto 1 mg per day. He developed extrapyrmidal side effects as tremors, rigidity and later dyskinetic movements of lips with shortness of breathing, dyspnoea, grunting or gasping. He was referred to the pulmonologist who got the neccessary medical work up done, which was normal. A diagnosis of respiratory dyskinesia was made. Respiratory dyskinesia is an under-recognised and distressing condition that clinicians need to be aware of when treating patients with anti-psychotic medications. And also there is a need to regularly examine patients on antipsychotics for any evidence of dyskinetic movements including respiratory musculature for early diagnosis and better outcome. This case report also is worth reading for professionals of other specialties also because of the presentation of this patient, it can be easily misdiagnosed and result in poor outcome.

Evaluation of Larvicidal Efficacy of Ricinus communis (Castor) Plant Extract and Synthesized Green Silver Nanoparticles against Aedes albopictus.

BACKGROUND: Aedes mosquitoes are the most important group of vectors having ability of transmitting pathogens including arboviruses that can cause serious diseases like Chikungunya fever, Dengue fever and Zika virus in human. Biosynthesis and the use of green silver nanoparticles (AgNPs) is an important step in the search of reliable and ecofriendly control of these vectors. METHODS: In this study an aqueous leaves extract of Ricinus communis (castor) and silver nanoparticles (AgNPs) synthesized from this extract were evaluated as larvicidal agent for 2nd and 3rd instar larvae of the Aedes albopictus. Different concentrations (50, 100, 150, 200 and 250ppm) of plant extract and synthesized nanoparticles were prepared and applied on second and third instar larvae. The percent mortality was noted after 6, 12, 18, 24, 30, 36, 42 and 48H of exposure and subjected to probit analysis to calculate LC50 and LC90. RESULTS: Synthesized Ag+ nanoparticles were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (XRD). The nanoparticles were more toxic against larvae of Ae. albopictus with LC50 value (49.43ppm) and LC90 value (93.65ppm) for 2nd instar larvae and LC50 (84.98ppm) and LC90 (163.89ppm) for 3rd instar larvae as compared to the plant extract (149.58ppm, 268.93ppm) and (155.58ppm, 279.93ppm) for 2nd and 3rd instar larvae of Ae. albopictus respectively after 48H. CONCLUSION: Our results suggest the extract of R. communis and synthesized nanoparticles as excellent replacement of chemical pesticides to control the vector mosquitoes.

Role of Prophylactic Antibiotics in Critical Care of Stroke Patients - A Preventive Approach to Post-stroke Infections?

Post-stroke complications are very common worldwide and the most common complication is infection. This contributes the most to the mortality rate in stroke patients. Among the infections, pneumonia and urinary tract infections are most common. Hyperthermia following stroke is associated with neuronal damage and worse outcomes. Post-stroke immunosuppression and activation of inflammatory mediators also cause infections. Based on the high mortality caused by post-stroke infections, various trials were done to seek the advantage that prophylactic antibiotics can give in the critical care of stroke patients. Antibiotics, including ceftriaxone (cephalosporin), levofloxacin (fluoroquinolone), penicillin, and minocycline (tetracycline), were used and the stroke patients were followed up to analyze the primary and secondary outcomes. It was concluded that early antibiotic therapy (mostly within 24 hours) leads to a reduced rate of post-stroke infections and reduced fever spikes, whereas follow-up for a longer period of time showed no better functional outcome. Furthermore, mortality and morbidity benefits were also not seen with prophylactic antibiotic therapy. This review helped us to put a nail in the coffin to the earlier thoughts that prophylactic antibiotics are necessary for the critical care of stroke patients.

The role of chemosensory protein 10 in the detection of behaviorally active compounds in brown planthopper, Nilaparvata lugens.

Chemosensory proteins (CSPs) play important roles in insects' chemoreception, although their specific functional roles have not been fully elucidated. In this study, we conducted the developmental expression patterns and competitive binding assay as well as knock-down assay by RNA interference both in vitro and in vivo to reveal the function of NlugCSP10 from the brown planthopper (BPH), Nilaparvata lugens (Stål), a major pest in rice plants. The results showed that NlugCSP10 messenger RNA was significantly higher in males than in females and correlated to gender, development and wing forms. The fluorescence binding assays revealed that NlugCSP10 exhibited the highest binding affinity with cis-3-hexenyl acetate, eicosane, and (+)-ß-pinene. Behavioral assay revealed that eicosane displayed attractant activity, while cis-3-hexenyl acetate, similar to (+)-ß-pinene significantly repelled N. lugens adults. Silencing of NlugCSP10, which is responsible for cis-3-hexenyl acetate binding, significantly disrupted cis-3-hexenyl acetate communication. Overall, findings of the present study showed that NlugCSP10 could selectively interrelate with numerous volatiles emitted from host plants and these ligands could be designated to develop slow-release mediators that attract/repel N. lugens and subsequently improve the exploration of plans to control this insect pest.

Evaluation of larvicidal efficacy of Ricinus communis (Castor) and synthesized green silver nanoparticles against Aedes aegypti L.

Aedes mosquitoes are the most important group of vectors that transmit pathogens, including arboviruses, and cause human diseases such as dengue fever, yellow fever, Zika virus, and Chikungunya. Biosynthesis and the use of green silver nanoparticles (AgNPs) is a vital step to identify reliable and eco-friendly controls for these vectors. In this study, Aedes (Ae.) aegypti larvae (2nd and 3rd instar) were exposed to leaf extracts of Ricinus communis (Castor) and AgNPs synthesized from the extract to evaluate their larvicidal potential. Synthesized AgNPs were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (XRD). Ae. aegypti larvae were treated with different concentrations (50-250 ppm) of the leaf extract and synthesized AgNPs. There were five replicates per treatment, in addition to a positive (temephos) and negative control (dechlorinated water). Mortality was recorded after 12, 24, 36, and 48 h and the data were subjected to Probit analysis. The nanoparticles were more toxic (LC50 = 46.22 ppm and LC90 = 85.30 ppm) than the plant extract (106.24 and 175.73 ppm, respectively). The leaf extracts of Ricinus communis were subjected to HPLC analysis to identify their chemical constituents. This study suggests that plant extracts and synthesized nanoparticles are excellent alternatives to hazardous chemical pesticides used to control vector mosquitoes. This is a potentially useful technique that can reduce aquatic toxicity from insecticide use.

A chemosensory protein MsepCSP5 involved in chemoreception of oriental armyworm Mythimna separata.

Chemosensory proteins (CSPs) have been suggested to perform several functions in insects, including chemoreception. To find out whether MsepCSP5 identified from Mythimna separata shows potential physiological functions in olfaction, gene expression profiles, ligand-binding experiments, molecular docking, RNA interference, and behavioral test were performed. Results showed that MsepCSP5 was highly expressed in female antennae. MsepCSP5 showed high binding affinities to a wide range of host-related semiochemicals, and displayed that 26 out of 35 candidate volatiles were highly bound (Ki < 10 µM) at pH 5.0 rather than pH 7.4. The binding sites of MsepCSP5 to candidate volatiles were well predicted by three-dimensional structure modeling and molecular docking experiments. Pursuing further, biological activities of M. separata to highly bound compounds elicited strong behavioral responses, such as alcoholic compounds displayed strong attractiveness whereas terpenes showed repellency to M. separata. The transcript expression level of MsepCSP5 gene significantly decreased after injecting target dsRNAs, and resulted in non-significant preference responses of M. separata to semiochemicals, such as 3-pentanol and 1-octene-3-ol. In conclusion, MsepCSP5 may involve in semiochemical reception of M. separata.